# Makita 18V LXT batteries....



## maverick

I have a few Makita 18V LXT Li-Ion cordless power tools. Recently, one of my battery packs wouldn't take a charge using the default charger. Since the battery is out of warranty anyway, I plan to take the battery apart to have a look when I get the time. Does anyone here know what type of cells Makita uses to build these packs? I saw a video on YouTube of someone taking one apart and know that there are 10 cylindrical cells in a 5S, 2P configuration. If the fault is the result of one or two dead cells, would it be as simple as replacing those cells? The thing I'm most unsure about is whether or not the charger will reject the new cell(s) inside the pack since Makita claims that the charger communicates with the pack when charging. 

On a different note, my cheapo no-brand multimeter just died on me and I'm looking for a replacement for it. I want to step up to a Fluke but find myself inundated with different model choices. I don't mind spending more for extra features so as to be sure I won't need upgrade if/when I decide to get more involved in electronics. I would appreciate any recommendations.


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## Alan B

Makita reportedly uses Sony Konion LiMn cells. Generally it is the first pair. There are 10each 18650 cells in 5S2P.

Replacing the first two cells is possible, and has been done. I found a video about it on Utube. Not a lot of detail on replacement but lots of info about taking the pack apart.

The problem is the battery memory chip tells the charger the pack was bad. Once that happens it is not clear how to get it to try charging again. You could charge with some other charger. But if the memory on the battery tells the Makita charger the pack was bad it apparently won't try to charge it any more.

I have not verified this but there is lots of info on some of the eBike forums on these batteries.


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## abarth_1200

I have found a few 'dead' makita 18V LXT batteries on ebay for cheap, is it maybe worth while getting one and bump starting it, with a higher voltage.

I have succesfully done this with one of my AW cells that went dead and read zero on my volt meter, I just zapped it with a 9V battery and its fine now, holds its charge well and takes the usuall time to recharge.


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## joegreen42

I have successfully repaired a Makita LXT 3 AH pack by replacing the dead cells with good cells from a donor pack. The battery memory chip prevents the pack from being charged from a Makita charger but you can use a charger that terminates at 21vdc. I took my repaired pack to Makita's headquarters in La Mirada, CA. They had no way to reset it and offered no other advice.


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## TheEpeter

This thread is exactly why I signed up for this forum! Awesome!

Now, has anyone figured out how to "fix" or replace the memory chip so that you can replace the cells and then reuse the battery in the charger? 

Also, is there a way that any of us knows about to remove any memory restrictions?

I ask because my father used the fully charged batteries for about 5-10 minutes each then threw them back on the charger. Now they only hold a charge for 5-10 minutes of power which sux. I'd rather not have to replace them. If I could just hack the chip and reset the memory values, that'd be best/easiest.


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## Toolmon

I did a lot of research on the net about early failure of Makita lithium batteries. My conclusion: this
battery has design flaw that shuts down these batteries prematurely.  If the battery sits discharged for a long
time, it's very likely to spuriously fail.  The symptom is flashing red and green lights on the charger, for a battery with infrequent use.  [This is not the same as an actual worn out battery that is several years old and has many charges on it, say 500 charges or more.  That is normal wearout, not the premature failure I mentioned.  See below for some ways to fix a worn out battery.]<br><br>The good news is Makita will replace the battery free if it has a low charge count (for sure under 150, some say under 300), regardless of warranty.  The bad news is you lose time and money dealing with it, and a lot of people don't know about the free replacements. Makita should recall the batteries, but they are quietly ignoring the problem.  Most people just buy a new battery, so Makita has a conflict of interest here.  Most of my power tools are Makita, and they usually last for years, top quality.   I'm very surprised at the way Makita is (not) dealing with this lemon.<br><br>Background: Lithium batteries
can burn or explode if abused. They need monitoring, for safety reasons.
So Makita put in a smart control board in the battery
pack. The control board monitors charging voltage, current, battery
temperature, number of charges, and remembers all that. Good idea,
right? But.. there is a design bug. The battery control board draws
power only from the first cell of the 5 cells in the battery. If you
leave it sitting for a while, the control board will deep discharge that
first cell to zero, while the others remain charged. To the control
board or possibly the charger, that looks like a shorted cell, which
could overheat, and the control board remembers it.  If you try to charge
it more than 3 times with an apparently deep discharged cell, the conservative software in the control board locks the battery permanently! The
control board tells the Makita charger that the battery is unsafe to charge,
and prevents charging in the Makita charger.  Once "bricked", the battery cannot be reset.<br><br>This is a design bug.  The
key evidence is the apparent dead cell is almost always that first cell, the
one that powers the control board.  Once locked, the control board can't be reset.  This problem is so common that Makita Service Centers will replace your dead battery if it shows very low usage, under 150 charges, regardless of warranty status.  So, they know about the problem, but have not recalled the battery officially.  They let you buy a new battery instead!  That's not right.   We should not have to deal with premature failures
caused by a known design defect.  Who has time on the job, and who has
money to throw away?<br>
<br>If you have a locked battery with low use, contact the Makita Service Center near you for a replacement.  If they won't replace it, it may still be usable.  The workaround is to charge it on third party chargers, that ignore
the control board. Aftermarket chargers cost about $60 on eBay, a lot less than a new battery.  They take longer to charge the battery, 2 hours instead of 20 minutes for the Makita charger.  No free lunch, but at least you can save your perfectly usable battery from landfill.<br><br>I can think of many engineering changes to fix this. For
example, Makita could reprogram the battery control board or charger so
it did not lock up a good battery, or the control board could draw power
from all 5 cells so this is less likely to happen to a single cell, or
use a separate coin cell for the control board, or ... well, as you can
see there are many technical options.  My point is that
Makita's engineers need to pick a solution and fix this problem.<br><br>This serious
problem has been identified, and it needs to be fixed. In my opinion,
Makita should recall these batteries and fix this problem, and release a revised battery design for new sales. If not, Makita's reputation will
continue to suffer, and there could be a class action lawsuit too.
Makita is infuriating customers and harming its reputation. <br>________________<br><br>Worn out lithium batteries:  If your batteries are many years old and have had a lot of use or been subjected to high heat, they could simply be worn out.  That's a different problem.  Lithium cells do wear out, and they also permanently lose capacity each year - about 20% per year, faster if stored hot.  Makita knows this and they derated these batteries to allow for shelf life.  The cells are actually good for 2400 Mah when new, but Makita rates them as 1500 Mah to be conservative.  <br><br>You can repair these batteries by replacing cells, either some or all.  Watch this youtube video on how to open the battery pack:  <br><br>http://www.youtube.com/watch?v=Z5taguEdlkY<br><br>The cells are Sony 18650 size in 2400 mah capacity.  These are not sold retail, only to manufacturers and repair centers.  You have to get them from another Makita pack, or many laptop batteries use them.  There are 5 in the 1815 battery, 10 in the 1830 battery.  If the failure is just in the first cell, I'd take it to Makita for possible replacement.  <br><br>You may be able to trickle charge a cell and bring the pack back to life.  The Tenergy Combo charger is a safe charger for this:<br>http://www.amazon.com/Combo-Special-Tenergy-Balance-Charger/dp/B00466PKE0<br><br>If more cells are bad, measure the voltage on each cell or cell pair,
and replace as needed.  If you have more than half bad, replace them
all, becasue the rest will go soon.  If you replace them all, they don't
have to be Sony, just any quality cell, 18650 size 2400 mah or better,
from a good maker.  You can find them on ebay.<br><br>Here is a website that deals with repairing an older NiCd pack.  The cells are different but the procedure is similar.  Good photos step by step:<br>http://www.kichline.com/chuck/fixit/makita/Default.htm<br><br><br>


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## 2saddlehorn

I've been researching the Makita batteries for someone who tried to fix it himself. I saw your post and wanted to thank you for the information. Can Toolmon contact me directly for more detailed questions?


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## MakitaBatteryExpert

Toolmon said:


> I did a lot of research on the net about early failure of Makita lithium batteries. My conclusion: this
> battery has design flaw that shuts down these batteries prematurely.  If the battery sits discharged for a long
> time, it's very likely to spuriously fail.  The symptom is flashing red and green lights on the charger, for a battery with infrequent use.  [This is not the same as an actual worn out battery that is several years old and has many charges on it, say 500 charges or more.  That is normal wearout, not the premature failure I mentioned.  See below for some ways to fix a worn out battery.]<br><br>The good news is Makita will replace the battery free if it has a low charge count (for sure under 150, some say under 300), regardless of warranty.  The bad news is you lose time and money dealing with it, and a lot of people don't know about the free replacements. Makita should recall the batteries, but they are quietly ignoring the problem.  Most people just buy a new battery, so Makita has a conflict of interest here.  Most of my power tools are Makita, and they usually last for years, top quality.   I'm very surprised at the way Makita is (not) dealing with this lemon.<br><br>Background: Lithium batteries
> can burn or explode if abused. They need monitoring, for safety reasons.
> So Makita put in a smart control board in the battery
> pack. The control board monitors charging voltage, current, battery
> temperature, number of charges, and remembers all that. Good idea,
> right? But.. there is a design bug. The battery control board draws
> power only from the first cell of the 5 cells in the battery. If you
> leave it sitting for a while, the control board will deep discharge that
> first cell to zero, while the others remain charged. To the control
> board or possibly the charger, that looks like a shorted cell, which
> could overheat, and the control board remembers it.  If you try to charge
> it more than 3 times with an apparently deep discharged cell, the conservative software in the control board locks the battery permanently! The
> control board tells the Makita charger that the battery is unsafe to charge,
> and prevents charging in the Makita charger.  Once "bricked", the battery cannot be reset.<br><br>This is a design bug.  The
> key evidence is the apparent dead cell is almost always that first cell, the
> one that powers the control board.  Once locked, the control board can't be reset.  This problem is so common that Makita Service Centers will replace your dead battery if it shows very low usage, under 150 charges, regardless of warranty status.  So, they know about the problem, but have not recalled the battery officially.  They let you buy a new battery instead!  That's not right.   We should not have to deal with premature failures
> caused by a known design defect.  Who has time on the job, and who has
> money to throw away?<br>
> <br>If you have a locked battery with low use, contact the Makita Service Center near you for a replacement.  If they won't replace it, it may still be usable.  The workaround is to charge it on third party chargers, that ignore
> the control board. Aftermarket chargers cost about $60 on eBay, a lot less than a new battery.  They take longer to charge the battery, 2 hours instead of 20 minutes for the Makita charger.  No free lunch, but at least you can save your perfectly usable battery from landfill.<br><br>I can think of many engineering changes to fix this. For
> example, Makita could reprogram the battery control board or charger so
> it did not lock up a good battery, or the control board could draw power
> from all 5 cells so this is less likely to happen to a single cell, or
> use a separate coin cell for the control board, or ... well, as you can
> see there are many technical options.  My point is that
> Makita's engineers need to pick a solution and fix this problem.<br><br>This serious
> problem has been identified, and it needs to be fixed. In my opinion,
> Makita should recall these batteries and fix this problem, and release a revised battery design for new sales. If not, Makita's reputation will
> continue to suffer, and there could be a class action lawsuit too.
> Makita is infuriating customers and harming its reputation. <br>________________<br><br>Worn out lithium batteries:  If your batteries are many years old and have had a lot of use or been subjected to high heat, they could simply be worn out.  That's a different problem.  Lithium cells do wear out, and they also permanently lose capacity each year - about 20% per year, faster if stored hot.  Makita knows this and they derated these batteries to allow for shelf life.  The cells are actually good for 2400 Mah when new, but Makita rates them as 1500 Mah to be conservative.  <br><br>You can repair these batteries by replacing cells, either some or all.  Watch this youtube video on how to open the battery pack:  <br><br>http://www.youtube.com/watch?v=Z5taguEdlkY<br><br>The cells are Sony 18650 size in 2400 mah capacity.  These are not sold retail, only to manufacturers and repair centers.  You have to get them from another Makita pack, or many laptop batteries use them.  There are 5 in the 1815 battery, 10 in the 1830 battery.  If the failure is just in the first cell, I'd take it to Makita for possible replacement.  <br><br>You may be able to trickle charge a cell and bring the pack back to life.  The Tenergy Combo charger is a safe charger for this:<br>http://www.amazon.com/Combo-Special-Tenergy-Balance-Charger/dp/B00466PKE0<br><br>If more cells are bad, measure the voltage on each cell or cell pair,
> and replace as needed.  If you have more than half bad, replace them
> all, becasue the rest will go soon.  If you replace them all, they don't
> have to be Sony, just any quality cell, 18650 size 2400 mah or better,
> from a good maker.  You can find them on ebay.<br><br>Here is a website that deals with repairing an older NiCd pack.  The cells are different but the procedure is similar.  Good photos step by step:<br>http://www.kichline.com/chuck/fixit/makita/Default.htm<br><br><br>


Success! Thanks for the info. I was able successfully replace 2 of the defective cells from an original Makita BL1830 lithium battery. The trick is to replace as soon as the charger report an red-and-green warning light. If you tried to charge the defective battery for more than 3 times, it bricks the battery permanently and the only 2 ways now to fix that is to use a 3rd party Li-Ion charger or swap out the circuit board.


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## jbrett14

Does anyone know if there has been a lawsuit yet?

This has been a very informative thread. Thanks to all who posted.


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## nelstomlinson

Could someone post a link to an aftermarket charger that will charge a bricked battery, please? Google doesn't seem to know about them.

Is there some way to get the Makita charger to ignore the chip in the battery pack? A switch to turn off that check would probably be cheaper than a second charger.


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## 2saddlehorn

Yes, there is pending investigation for a class action lawsuit. I would be interested to know if I can get direct contact information from anyone interested in recovering their losses on the battery. The more consumers who have evidence, the better likelihood of success on the case. If the moderator will allow it, I will be happy to post the status of the lawsuit and try to get those compensated who have a defective battery. I would need to have direct contact between me and the consumers.



jbrett14 said:


> Does anyone know if there has been a lawsuit yet?
> 
> This has been a very informative thread. Thanks to all who posted.


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## jcssj2

For anyone interested, I had the internal pc board brick 3 of my LXT batteries. The interesting part is the cells aren't bad. No need to replace any of them. The problem is they won't charge in the factory charger ever again. To my understanding if you try to charge with the makita charger 3 times the battery will never charge in the makita charger again. These batteries take a charge and hold a charge and are usable. They just won't charge because of the internal chip. For future reference if anybody has a dead battery, take a good battery and use jumpers from the good battery to the bad one and they will take a charge. I just use a couple of 10mm or (1/4" if they aren't 2 thick) washers slipped in the clips and alligator clips to jump. It takes only about 5 minutes to recharge them like this. They will read 17+ volts that quick and will charge in the factory charger then. 

PS Anybody have more information on a potential class action suit. I'm sitting here looking at 23 dead makita batteries (only 3 are the lxt, 12 Nimh, 8 Nicd just sat too long there is the same type of issue where the charger won't charge whether there are dead cells or not) and the fact that I have 3 good batteries that won't charge due to this design flaw on the LXT and lack of any kind of support or help from makita is intolerable.


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## Therapy0

Hi everyone, 
I come across this thread via a google search.
I am a tradie who abuses the crap out of the LXT batteries, in 5 years I have had 2 fail. I have also collected a few 1830 packs that are buggered also.

I am quite competent when it comes to sussin' out faults, and I can report on all my failed packs it is always the first parelleled pair that goes. Some times they even seem to be reverse polarity!

I have loaded up a genuine makita pack with a "bricked chip" with new cells as required, but no deal, the charger ( blue fast charger ? ) rejects it instantly and on monitoring the current passed to the battery from the charger shows absolutely nothing.

Interestingly, there are a bunch of knock off cheap chinese packs on ebay for about $60, more for curiosity than anything I bought 1, it failed within about 2 months after reasonably heavy use, the same fault, the first 2 cells are basically a bit of wire.
I popped 2 new cells in and tried to charge, but after about 15 seconds the charger rejects it. Before the charger gives it the boot, it does actually take on a charge. The pack as a whole is still only about 16v, so very flat. I think the charger is rejecting based on an unbalanced situation, as the new cells at 3,8v the others much less.

It doesnt seem to matter how many times I put on the knock off pack, it always seems to charge for a bit then carck it, the real deal does not take a charge at all.

I might jump the dead pack with a good full one, and see if i can get the volts high enough for the charger to take it.

Would be nice if some brainiac works out how to render the smart chip not so smart. In the mean time there is the universal route!


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## Lurveleven

If you had a RC-charger, then you could try to charge and balance the cells before assembling the pack back together.


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## alpg88

i have 3 such drils at work, all still going strong, and are used almost daily. i have taken them apart, just to see how they are made. despite having multicontact plug, in addition to +,-, temp. the cells are not ballanced, in factory charger. the last sell, has wire soldered to negative and to the pcb. the cells are of that chemistry that alows overcharging, so the pcb basicly monitiors soc of the last cell, overcharging the rest in proccess. it is entirely possible to make a charging\ballanced plug\tail, and charge those in hobby charger, it wil be slower however. 
even thou i have 3 li ion makitas at work, i still prefer nicd milwaukee drill.


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## toolguru3

Hi fella's,

I have had my Makita lxt600 combi kit for about 4 months and have found that the batteries were letting me down. I have read the posts below and i can say that i think taking the batteries apart etc is way too technical for me. I am happy using the tools etc but taking them apart i`d rather take them to a shop and get them replaced. This leading me to my point, when i bought my combi kit from SCR*WF/X i had 2 batteries go down within 2 weeks. So i went back with my receipt and the complete kit in the same box as purchased and when i asked for a replacement under the warranty, i was blatantly denied. To simply put it, i was told "NO, You have to deal with Makita for that". So i spoke to a few lads on site and was told that they should replace them for me free of charge. I went to another tool store local to me A One Tools & Fixings Brighouse, and was absolutely amazed when i asked if they could help me with any advise and they told me to bring the batteries in for them to look at and if they were deemed faulty, that they would swap the batteries out for me with brand new ones under the warranty claim. This to me was the biggest blessing about buying this kit, aonetools helped me out so much regarding this and i`m just wondering if anyone else had has this scenario where they were blatantly told to go away but then found that another company would help them with there warranty claims??


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## nichol

So can you balance the Makita 1830 batteries with an RC Charger?


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## alpg88

nichol said:


> So can you balance the Makita 1830 batteries with an RC Charger?



theoreticly yes, but why??? 

all cells charge fully with factory charger, even thou most get overcharged in the process, but cells chemistry allows it somewhat. and you would have to take apart the pack, and solder balance tail to it. and at the end, you will, most liklely, not get any improvment, over factory set up. not to mention good bye warranty


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## itguy07

alpg88 said:


> all cells charge fully with factory charger, even thou most get overcharged in the process, but cells chemistry allows it somewhat. and you would have to take apart the pack, and solder balance tail to it. and at the end, you will, most liklely, not get any improvment, over factory set up. not to mention good bye warranty




I would think all LiIon tool batteries that are more than 4v would balance automatically as part of the charge circuitry. You don't want to overcharge LiIon and over time they can become un-matched and really be nasty in a tool (high current) environment.


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## alpg88

itguy07 said:


> I would think all LiIon tool batteries that are more than 4v would balance automatically as part of the charge circuitry. You don't want to overcharge LiIon and over time they can become un-matched and really be nasty in a tool (high current) environment.



thoses are not regular li co cells, (in factroy batteries), those cells can take overchrge, and are made for high current, and no, li ion cells do not balance automaticly, in those batteries, since there is no balance circuit. just monitoring of last cell in the pack. take one apart you'll see what i'm talking about.
i have few li ion drils at work that are used almost daily, we had no problems so far with batteries, all still work fine.


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## itguy07

alpg88 said:


> thoses are not regular li co cells, (in factroy batteries), those cells can take overchrge, and are made for high current, and no, li ion cells do not balance automaticly, in those batteries, since there is no balance circuit. just monitoring of last cell in the pack. take one apart you'll see what i'm talking about.
> i have few li ion drils at work that are used almost daily, we had no problems so far with batteries, all still work fine.



Then Makita is selling some junky LiIons. Even the lowly Ryobis have a cell balancer built in. Look at this page:
http://toolboyworld.com/eBay/Ryobi_Batt_Rebuild.htm 

Lots of circuitry and you can see that there are connections to the motherboard from each cell.

Also Miwaukee states they have balance circuitry in their batteries:
http://www.milwaukeetool.com/lithium-ion
http://www.facilitiesnet.com/equipmentrentaltools/article/Building-a-Better-PowerTool-Battery--3001#

Good LiIon tool batteries need to have balancing built in, either in the battery or the charger.


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## alpg88

i beg to differ, makitas work just fine, that i see firsthand, for years, how they do it, makes no difference to me. they use sony cells btw. 

Good li ions are those that work good, and makita does just that, if they can acheave it with simpler circuit, good for them, not a negative point by any means, ime.


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## Chodes

deleted
missed "reply with quote" - post made no sense without ti..


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## Chodes

alpg88 said:


> theoreticly yes, but why???
> 
> all cells charge fully with factory charger, even thou most get overcharged in the process, but cells chemistry allows it somewhat. and you would have to take apart the pack, and solder balance tail to it. and at the end, you will, most liklely, not get any improvment, over factory set up. not to mention good bye warranty



I believe Lurveleven suggestion was for Therapyo to balance charge the pack he was unable to chage with makita charger due to first 2 cells (same problem with his knockoff pack).
He had pack apart, so hope was to balance charge to restore pack then continue to use with Makita charger.


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## dwminer

Does this problem still exist with the newer 18volt XLT batteries and
the DC18RA charger? Thanks Dave


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## alpg88

dwminer said:


> Does this problem still exist with the newer 18volt XLT batteries and
> the DC18RA charger? Thanks Dave


i,m not aware of any changes made to makita batteries or chargers lately, neither i'm aware of any problems they have, i have few of them at work that are used daily, no problems with either.


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## SemiMan

On a related note, had a similar issue with a Lenovo laptop battery pack. The laptop was broken and one of the internal cell connections for the balancing, not the power connection, came off. No worries thought I, just a little bit of solder and we are good to go. Unfortunately, the battery management chip bricked the battery pack and there was nothing that could be done about it. Went on the web and found numerous complaints about situations where the pack just bricked even though it still had a lot of capacity and nothing could be done about it.

Bad corporate citizenship at the end of the day .... along the lines of bricking printer cartridges but I would say in this case even worse as battery packs are likely a small replacement market overall.

Semiman


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## Nate154

Can someone speak to whether you can replace your battery, if defective, regardless of warranty, like someone above mentioned? I called Makita and they weren't having that.


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## mucek

I have started reverse engineering on the Makita LiIon battery pack. So far it's clear, that the communication between the MCU and charger is done by UART on MCU (MCU connects to battery management chip via I2C). There will be plenty of thing to find out until the hacking of the locked chip will be possible. In addition, there's also EEPROM in the battery management chip, which may also contains some "lock". 

In next days I'll first try to replace battery managment chip between locked and unlocked battery to see, if the issue is in MCU's eeprom or in battery management chip. (first option is more possible) I'll also try to "sniff" on the data lines to see, what messages are exchanged between the battery and the charger. Lots to doo, so if any has some more information on the protocol itself, I'd be glad to know it ...

Follow this for more details: http://www.ecat.si/2013/09/makita-hacking-part-i/?lang=en

Regards,
Gregor


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## elduderino970

Hi Guys,
This thread is great! Glad I found it!
I have an 1830 battery that is giving the red/green flash from the factory charger. I know this sequence has happened at least twice. Hopefully the control board isn't already bricked. I opened up my pack and found one cell showing 0 volts. I have tried to charge just that cell with my Accucell 6 charger but it won't take a charge. So, that means I am down to replacing the cell. I have read above that these packs actually use Sony *LiMn instead of the usual* *LiPo* 18650s. I have lots of 18650s but none are LiMn. I am concerned that it isn't safe to mix the two types in the same pack. So far, I haven't found any info to that idea on google. *Do you guys know if I can drop a LiPo into the mix with the LiMn cells?*
Thanks!
John


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## Bullzeyebill

elduderino970 said:


> *Do you guys know if I can drop a LiPo into the mix with the LiMn cells?*
> Thanks!
> John



Welcome to CPF. The answer is no, do not mix different chemistries. Please start your own thread with this question as it is OT here. Thanks,

Bill


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## elduderino970

Bullzeyebill said:


> Welcome to CPF. The answer is no, do not mix different chemistries. Please start your own thread with this question as it is OT here. Thanks,
> 
> Bill



Thanks for the welcome. I tried to join several months ago and I was auto-banned. I found this thread and some more searching lead me to the faq on the IP/domain whitelist issue. I used another email and it worked!
With my new found knowledge, I will be shopping/diving for some LiMn cells. Thanks again!
John


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## mucek

Try to search for Konion LiIon cells - those are "the ones".

In the midtime I already did some research as well as some analisys. Looks like that protocol is not UART (regardless that it's UART0 pins of the microprocessor are used).
I have recorded some data with good and locked battery, you can check here for the osciloscope image as well as data (.CSV)
http://www.ecat.si/2013/10/makita-hacking-part-two/?lang=en

Regards,
Gregor


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## delus

I have eight of these batteries and lock most of them in my truck toolbox year round. It's gotta get pretty hot in there in the summer, and cold in the winter. Have not had a failure since I switched to makita two years ago. I am quite impressed with makita tools all around.
Thought I'd sneak in my slightly off-topic trick for getting Makita tools on the cheap.

They have a few of those display trucks that travel to events around the country. FIND ONE. They attend a lot of NASCAR and Motocross events. Trade shows. You might ask the right person at your closest Makita factory authorized repair center. The makita website has an events calendar. Just figure out some way to FIND ONE of those trucks.
Go to the event with some C-Notes, and wait until it's over. Wait until almost everyone has gone home. Wait until they are just about to pack up and leave. The guys in that truck are now ready to deal.
Walk around and don't look too interested, say something like "i have a few DeWalts now, but I liked your stuff every time I used one."

With this technique in 2011 I got a 15 tool set, the biggest set they offer, for $1050, which is $450 less than it is offered anywhere else.
A few weeks ago I got a BRUSHLESS impact-driver and drill set for $230, which is $50 less than I've seen the non-brushless kind.


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## keithwins

delus said:


> Have not had a failure since I switched to makita two years ago. I am quite impressed with makita tools all around.



Interesting point I just figured out: in watching a youtube video disassembling a Makita BL1830 battery pack http://www.youtube.com/watch?v=3yBnY54o2vw, I noticed he said he was working on the newer style, within the last couple years (video was posted a year ago). I realized, as I watched, that his battery was different than mine, and had leads to each set of parallel cells. So the newer Makitas are capable of balance charging, whether or not they actually do it (I would assume they do). This is actually sort of interesting, and even makes me wonder if I could add official Makita balancing to my current batteries: all the leads are there except a couple short internal wires inside the battery itself... I had noticed that the Makita battery connection had just enough leads for a balance charger, but in mine they aren't used. I've been gearing up to try to recondition/repair/swap cells in some of the 5 dead batteries I have lying around, and even splurged $20 for an IMAX B6 charger for the project. I regret I don't have the newer Makita battery/charger, and I may open up my charger to see if it has balancing set up, just for kicks. I also imagine that ebay no-name cheap batteries may not have this balancing set up... In fact, both the batteries I've just open are precisely that, but I've got several dead official Makita batteries also, I'll check them soon. Most of these are 3-6 years old.

Note, in the two batteries I've opened, one or two sets of cells were dead, and everything else was reading near 3V or better, so they should be salvageable, though the control chip in the battery bricks the battery if it's registered as dead and recharge is attempted 3 times, as I understand. I can't help but wonder if setting up the official Makita balancing system wouldn't reset this... Hmmm. Gotta wonder.

Keith


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## elduderino970

The good news is the Makita Girls are working today. The bad news is that they are in Alaska. Makita Appearances
Makita has a separate calendar for trade shows and is empty for the rest of the year. Tradeshows

I just talked to someone at Interstate Batteries. He said he has worked there for six years and was capable of discussing LiMn etc. He said they are similar enough to replace with a Li-Ion. I am wondering about the experiences of others in this 3 year old thread, several have replaced cells. I wonder if any have been non-LiMn and how that is working out...


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## keithwins

So: I'm realizing now that Makita has officially released a balancing charger, which presumably interacts with the newer batteries. The older Makita batteries are definitely not wired for balancing, though all the contacts are there. The newer "rapid" chargers are the dc18rc, vs. the older dc18ra. I don't know of any way of identifying whether the batteries you have are the newer balancing type by looking at them, although one could measure the voltage across the balancing leads without having to open the case... Now that I'm down to one working battery, next time I have money I might switch over to the newer system, but it would end up costing several hundred dollars...


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## mucek

@keithwins:
Can you please post some macro shoots of the PCB for 18 V BMS circuit inside the battery? Currently I am only working on a protocol analisys with 36 V batteries, which DO HAVE some balancing incorporated through bq77pl900 battery managment chip, but I am not sure about the 18 V; I assume they should use quite the same protocol for the smaller batteries (need to get one  ).

I also noticed, that Makita uses a BIG safety reserve on a charging voltage, as cells, charged with Makita charger, only reach 4,00 V per cell. Usual charging voltage for this cell type is 4,10 - 4,20 V, which practically means around 25% of the usable capacity (tested with 4 36 V packs, used for caving hammer drill - charged with Makita charger, 8-9 holes were drilled before the battery went empty; charged with custom charger (and balancing) to 4,15 V, 12-13 holes were drilled (which isn't significant, if you first have to climb in a cave for several hours to get to the point, where you do the drilling!). 

However, charging to lower voltage for sure increases battery lifetime, but having set limit to 4,00 V is just a bit to low for my taste. Well - if they would like to have a REAL lifetime, then they should protect the cells from over-DISCHARGING! (Which they don't! Machine runs slower and slower and slower ... As the battery doesn't have some MOSFET or something to disconnect it when one of the cells is (too) low, I would expect that the drilling machine would have done it. But - as the machine work also without BMS circuit, only the full pack voltage can be measured - if even so?!)

I am working on a simulating the communication between the charger and the Makita BMS and then I'll see, if faking only initial pulse is enough to make the charger "alive" or more will have to be done ...

Regards,
Gregor


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## keithwins

Hi Gregor:

I only have the old-style Makita 18v batteries, that don't have balancing built in. I would expect that they might dare come closer to fully charging the battery when using a balancing charger, but I have no idea if that's true. I also wonder if you fixed dead cells in a dead battery, and re-wired it to balance, and used a balancing charger, would it notice/care that it had been "bricked" by a non-balancing charger? As far as I can tell, there's no reason for it to, since the charger would be able to tell that each of the cell pairs is fine. But that comes down to how they build/program the BMS. I don't know that much about batteries, honestly, but it does seem like over-discharge protection would be nice... Other people use my tools, and I just can't get them to stop using them after they start to slow down, they often run them dead. Hence my big pile of dead batteries.

I'm going to try to attach a pic, but it's not going to be that helpful I think: I can't take a pic of the back of the BMS PCBs without removing them, and I can't do that without desoldering/cutting, and I don't feel like doing that, since I don't need to. You might be able to find this elsewhere, or get someone like drbass on youtube who I believe regularly dismembers these batteries.


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## Bullzeyebill

Your image is not working.

Bill


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## keithwins

No, I guess I have to host images on the web elsewhere to post them here? I think that's too much of a hassle. I'll email it to you if you want. Since it doesn't show the IC's that are on the back side, I'm not sure it's very useful to you.


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## Bullzeyebill

Try this, and this.

Bill


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## keithwins

Wow. That's pretty much of a PITA compared to most of the forums I participate in. But so be it.


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## Firedog91902

I've been able to repair Makita 18V Lithium batteries; use and charge them safely. I've found most bad Makita batteries, don't have bad cells. They have, for some reason gone out of Makita's safety range (usually voltage too low) and the battery's circuit blocks them from recharging . To Makita's credit, it's not easy to do, since most or all tools turn off at a set minimum voltage. So far, no one has found away to reset the battery's circuit failure mode.

A few bricked Makita batteries will have a bad cell or pair. There is a plethora of similarly failed laptop batteries with perfectly good, 18650 cells available for donor replacement cells. Usually, they are free or almost. 

The 18650 cells used in tools are a slightly different design than used in laptops. Laptop batteries discharge over 4 hours. Tools require higher currents for short bursts and faster charging. In addition, the older Makita batteries, for safety, are never fully charged (to 4.2 v/cell). Since the cells are charge in series and each cell's voltage is not monitored, it would be too risky. It's rare, but if the cells become unbalanced one might reach 4.5v while it's neighbor is only 3.9v and the circuit wouldn't know it. Because of this, each Makita cell is rated 1.5AH while 18650's harvested from old laptop batteries are rated 1.8 to 2.8 AH.

When ever possible, I use good Makita cells to replace bad Makita cells. But, I've also picked strong cells from laptop batteries and they seem to work fine. My favorite solution is to use all laptop cells in a Makita case but wire 3 cells in parallel instead of 1 or 2. That's 15 cells total so the battery is slightly taller and heavier, but the current load is now shared by 3 cells and the capacity is about double a 3.0AH Makita. Saws and grinders work much better than with genuine Makita 10 cell batteries. Converting a 5 or 10 cell case to 15 is simple. Screw 4, 4-40 circuit board standoffs into the top screw holes. Use long, 4-40 machine screws cut to the required length to assemble the bottom to the rest of the battery. This leaves a gap which can be wrapped with tape. The critical edges are still protected by the case and the battery is very sturdy.

To monitor and balance each of the 5 series wired cells or parallel cell sets, a connection is needed to the cell's positive and negative. That requires 6 wires. RC batteries use in line female connectors with .1" spacing between pins. These connectors are cheap and very common. Glue a 6 pin connector to the outside of the battery, holes pointing down (towards the label) on the end opposite the white release button. Then solder a 28 gauge insulated wire to the 1st pin of the connector and the other end to the battery negative. The 2 pin gets wired to the common connection of cell 1 and 2 and so on down the line until the 6th pin gets wired to the positive of the battery. 

It is best to balance and test cells before assembly, but you can also test cells in an assembled battery if you add the above discussed 6 pin connector. Or, simply use alligator clips to test the suspect cell(s). Use care, short are easy to do and the resulting sparks unpleasant.

I use 3 steps to test cells.

1. Charge the cell(s) with a single cell Li-ion charger. I use one from DealExtreme.com, Item # 132558, $5.40. These are designed to charge a bare cells to 4.2volts, but it is a simple matter to open them and solder 2 wires; one to the positive and one to the negative. On the other end solder to a 2 pin male that will plug into the 6 pin female connector. Each time you shift the charger pins one space, you are charging a different cell in the battery. Try to keep positive and negative straight, but if you get it reversed the charger senses the problem stops any damage. 

If the cell voltage below 2.5 v, the charger won't start the charge. If the low voltage is caused by an internal short, it's toast. More likely the cell was stored with an external load and it might still recover. Here's a safe method to find out. Connect a small Ni-MH cell (1.2 v) to the cell (positive to positive) and see if the voltage starts to recover. The internal resistance of the NI-MH cell will prevent very high current if the Li cell is internally shorted, but if the voltage doesn't start up in a few seconds it's bad. If the Li cell charges to 1 volt, switch to 2 Ni-MH cells in series. If it reaches 2 volts the charger should now work and charge the cell.

2. Store the charged cell 24 hours to see if the open circuit voltage drops below 4 v. If it does there is likely an internal short or other problem and the cell won't hold a charge.

3. Connect a 2 ohm resistor capable of 2 amps to the cell and note the voltage after 60 seconds. If it stays above 3.7 v it will probably work fine in a tool battery. If it's less, use it in a flashlight or other low drain device.

If all goes well, you now have a full charged, balance and tested battery with an added 6 pin connector. Purchase a RC voltage monitor (DealExtreme.com, Item #20024, $3.26). It comes with 7 pins on .1" centers (to monitor 6 cell batteries) but we use only the first 6 pins for our 5 cell, 18v system. Plug it into the added 6 pin socket and it will report cell 1, it's voltage, and so on through cell 5. Finally, it reports the total battery voltage.

Test the battery on various tools with the V monitor plugged in to see how the cells are doing under various loads. If one is especially weak then consider replacing it.

To recharge the battery after use, one could theoretically use the single cell charger 5 times. Of course that is ridiculously slow and time consuming. An RC balanced chargers is the preferred solution and it should plug into the 6 pin connector and charge the complete battery in one shot, carefully monitoring the voltage of each cell. They are a bit expensive and I don't have one so I don't have a purchase suggestion. 

Another way is to use a 19v or 20v DC laptop charger to charge all 5 cells wired in series. If the cutoff voltage maximum is 4.2v/cell then 21volts is the absolute maximum for safety. Connect the laptop charger to the battery's main + & - and monitor each cell's voltage. 20 volts works out to be 4.0V/cell which although not a full 4.2v charge, it is substantial and you probably wouldn't notice the difference in days work. 

I use a Kensington Universal Power adapter which can be set to any voltage from 0 to 24 volts, by changing the value of one 1 resistor. I set the voltage of the Power adapter to 1 volt above the battery's discharged voltage and increase it gradually during the first few minutes of charge. I then leave it over night with the charger at 20.5 v (4.1 v/cell) and get excellent performance. 

If the cells become out of balance, as shown by the V monitor, charge all 5 to 4.2V, in turn, using the single cell charger. 

One final consideration. Makita's chargers are fast. If an overnight charge isn't fast enough, then your are pretty much stuck frequently buying new batteries from Makita and using their chargers.


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## elduderino970

Thanks for the detailed info Firedog!
I recently replaced a bad pair from my 3.0ah pack with 2 Samsung INR-18650-15M (Knowingly against advice posted here). I matched the charge carefully and the pack was stable for a few days. However, with just a few minutes of use in a reciprocating saw, the whole pack was hot and the Samsungs were 10 degrees hotter at 115F. 
I have been scrounging for a failed Makita pack but I can't seem to find one. Right now, the only type of identical cells I have 15 of are IMR-18650BB from two 5s2p Graco packs. I already have the RC charger and voltage monitor.


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## mucek

Firedog91902 said:


> Another way is to use a 19v or 20v DC laptop charger to charge all 5 cells wired in series. If the cutoff voltage maximum is 4.2v/cell then 21volts is the absolute maximum for safety. Connect the laptop charger to the battery's main + & - and monitor each cell's voltage. 20 volts works out to be 4.0V/cell which although not a full 4.2v charge, it is substantial and you probably wouldn't notice the difference in days work.
> 
> I use a Kensington Universal Power adapter which can be set to any voltage from 0 to 24 volts, by changing the value of one 1 resistor. I set the voltage of the Power adapter to 1 volt above the battery's discharged voltage and increase it gradually during the first few minutes of charge. I then leave it over night with the charger at 20.5 v (4.1 v/cell) and get excellent performance.
> 
> If the cells become out of balance, as shown by the V monitor, charge all 5 to 4.2V, in turn, using the single cell charger.
> 
> One final consideration. Makita's chargers are fast. If an overnight charge isn't fast enough, then your are pretty much stuck frequently buying new batteries from Makita and using their chargers.



Charging 5 LiIon cells in series without supervising each cell voltage can be dangerous!!! Either use BMS circuit, which monitors the cells or AT LEAST put a 4V2 1W zener diode over each cell (reverse polarity), which may take some power instead of cells. Because especially when mixing old and new cells (or - even worse - hi power cells (machines) with low power cells (laptops etc)), there may be pretty great differencies between cells within single packet. Or - perhaps the simplest solution - use a charger with built in balancing circuit (hobbyking.com sells them for real small price!). This way you can also quick charge the cells ... (depends on a charger and cells offcourse).


Regards,
Gregor


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## ginbot86

I just did some research into the bq77PL900, and it appears to only be an analog front-end for the microcontroller in the battery pack. Although the bq chip has support for standalone protection, the use of a microcontroller in the battery tells me that it's being used in "host-control" or non-standalone mode. The bq chip also doesn't appear to have any sort of permanent fault shutdown like many laptop batteries have; this tells me that all the charge-disabling functions are done inside the microcontroller. I have the PC interface and software that Texas Instruments provides, but don't have any batteries around that I can test out with the software.

Long story short, the bq77PL900 chip is not one of the droids that we are looking for.


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## elduderino970

I have three separate topics within this post.
1.
So my other 3.0ah battery gave me the red/green flashing lights once. Now that I know about the "3 strikes and your battery is bricked" rule, I don't want to try it again until I ask the experts. On this occasion, I connected the battery to the charger and then plugged the charger into the wall instead of connecting to the wall THEN connecting the battery. Would that cause the red/green flashing lights? I checked each cell with a volt meter and they are all reading around 3.95. My only other guess is maybe some of the cells have developed high internal resistance. Is there a specific list of conditions that cause the red/green flashing lights? Any ideas for saving this pack?

2.
Thanks to F*iredog91902*'s suggestion, I made a super pack out of two rescued recycled Graco packs! It seems to work well and hasn't disintegrated in the reciprocating saw.  pic1. pic2.

3. After I spent way too much time tinkering on my super battery, I found that Amazon and eBay sell non-genuine replacement packs in several varieties - just the cells and circuit, a fully assembled 3.0ah pack and a fully assembled 4.0ah pack. Search "Makita Replacement Battery" on either site, do check reviews, warranties etc.

John


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## torukmakto4

Nice super pack.

I have built a number of packs from these high power 18650 cells (bought new, not scavenged) which I use in place of lipos for various purposes and I really like these sort of batteries. Sooner or later I am going to build a big 6S (possibly 6s2p) pack for an old drill of mine and make a custom hard case with the original slide adapter for the drill. I am thinking 6s2p with Samsung INR18650-20R, 22.2V 4.0Ah 44A continuous, should beat the old 20s 4/5SC nicad pack and garbage charger hands down.

What firedog suggests, I would say falls into the "not recommended" category. That is about how RC Lipo was handled in the early 2000s when it was new and everyone wanted to be a LiPo cowboy and use the latest tech, and what do you know, there were a ton of preventable fires caused by what we now know as stupidity.

Improvised chargers (I'm not talking about homebrew or adapted CC/CV chargers, I am talking about using a wallwart power supply to charge) are dangerous. You have no proper current limiting and no termination. Going only to 4.1 is safer but that type of rig to charge Li-ion is just not worth it, hobby chargers are about $20 now, get one! Plus with a hobby charger you can charge as fast or faster than Makita does with the OEM charger, up to the charge current limit published by the cell manufacturer, and that will be a balancing charger that is aware of cell voltages and much safer. Unbalanced Li-ion chargers belong with the dinosaurs, dead and buried.

Laptop cells, let's generalize as 2000mAh 2C = 4A continuous discharge rating. 3p is 12 amps. I've seen worse misapplications I guess, but still exceeding cell manufacturer's specs, I would not run that on a tool that can generate huge current transients. The stock packs have high power, low IR cells in them for a reason. Don't put LiCos in them, that's just scary.


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## elduderino970

Thanks for the quick reply* torukmakto4*! Btw, I am using an Accucell 6 and I have a voltage monitor to use to watch the pack. The cells in the two Graco packs are these: Model Number IMR18650BB, Nominal Capacity 1200mAh,Nominal Voltage 3.8V, Weight 45g, Size(diameter×Height) 18mm×65mm, Charging Temperature 0~45°C, Discharging Temperature -20~80°C, Storage Temperature -20~35°C, Cathode Material LiMn2O4. 
If any cells start to go bad, I can try to reconfigure them as 3s instead of 4s. But that might not cut it with these cells. Which model of loose cells do you recommend for purchasing new and replacing all at once? The Samsung INR18650-20R you mentioned? I don't use this too often but I do like knowing it will work when I need it.
Any thoughts on the red/green flashing from my other pack that appears healthy from my volt meter? My dad is using this pack so I will probably have to replace it with the 'best' knock off pack I can find instead of switching to hobby charging. I have asked one seller what type of cells are used in his packs but I don't think he wants to open one up to find out.

John


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## mucek

I guess, the original cells are Konion 18650 - they were used in RC hobby world as well and were very reliable, but expensive. DO MIND, that you must not mix old cells with new one ... Not good idea at all: if you do built a new pack, then use only new cells (same type, if possible same series).

About your "flashing battery": try to load the battery with some load (i.e. car bulbs - do mind, that you connect them in parallel to get enough voltage, otherwise they won't light for a long time  ) and then measure the cell's voltage. If one of cells has significantly different internal resistance, this will be clearly shown, as this battery (under load) will have lower voltage.
I would also try to do a cycle with those batteries using RC charger with balancer (but only charge to 4,00 V/cell and discharge to 3,30 V/cell). It might be, that cells are too unbalanced (Makita balancing circuit isn't really a powerful one ...).

Regards,
Gregor


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## mucek

Huh, and some more words about hacking the Makita's BMS unit ... 

Currently I am so busy, that I didn't make any significant improvement in the protocol decoding. However, I have designed a programmable 6S BMS with proper data output, which will be (later) able to replace (locked) original Makita's BMS in 18 V batteries. Basic BMS functions are already working, but I have to dig deeper in order to persuade Makita charger to give me some power ... 

Regards,
Gregor


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## torukmakto4

elduderino970 said:


> The cells in the two Graco packs are these: Model Number IMR18650BB



Lishen IMR18650BB. Chinese made LiMn (IMR) cell, kind of cheap and not top notch, probably not as long lived as the name brand hybrid cells, but a stock cell in many tool packs. If you look at the Dewalt Owners Forum you will see them show up in a lot of teardowns.

The pack should be good for current capability, even if you cut it down to 3p. I googled and am seeing a lot of 2p tool packs with them.



elduderino970 said:


> Which model of loose cells do you recommend for purchasing new and replacing all at once? The Samsung INR18650-20R you mentioned? I don't use this too often but I do like knowing it will work when I need it.



For making a "super pack" and using a hobby charger and other commonplace Li-ion management tools: Use whatever is appropriate, and you like. There are tons of cells out there.

I use quite a number of Sanyo UR18650SAX. Only 1300mAh, but 25A continuous rated and cheap, they make good robust high performance RC-type packs for low cost. Sanyo also has the successor WX and RX, 1500 and 2000mAh 20A cont.

Sony is a serious contender. You can't go wrong with the US18650VTC3, 1600mAh 30A cont. or the US18650VTC4, same rating and more capacity. I wouldn't mess with the older V and VT, 4.1 charge voltage, less than 20A and less than 1500mAh, Konions anymore for a DIY pack.

Samsung, has the 20R and a new 24R, 2000/2400mAh 22A cont.

LG apparently has a 2500mAh 30A cell!

If you are recelling a stock pack to use the stock BMS? I dunno, I will just note that some makita and other packs do not balance or monitor individual cells, and I would not use anything but the original (proven safe and balance-maintaining) Sony Konion V/VT.

Also I would not assemble by soldering. I made myself a tab welder.


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## jackbombay

Lurveleven said:


> If you had a RC-charger, then you could try to charge and balance the cells before assembling the pack back together.





Lurveleven said:


> If you had a RC-charger, then you could try to charge and balance the cells before assembling the pack back together.



I disassembled my makita pack and remoed the electrical connectors from the circuit board, then used a 5" grinder with a 36 grit sanding disc to removed everything from the circuit board, then put the connectors back on the circuit board with JB weld, and used the 6 connectors on the yellow plastic fitting on the pack as balance charge leads. Now, I can balance charge my packs every time I charge them, I use the fitting from the makita charger and an aftermarket Lion charger to charge the packs. 

The makita packs are designed to fail, the circuit board only pulls power from one of the cells in the pack, thats why the dead cell is always the 1st one, once that cell gets discharged disproportionately compared to the rest of the cells the makita charger will no longer charge the pack. The makia charger does not balance charge the pack, it is a truly terrible design. 

I really like the 18v tools or I would have quit using makita long ago, the cordless concrete vibrator and the 6.5" circular saw are so nice, and the the vibe was expensive enough that I "need" to keep it. I hope that by eliminating the curcuit board from the battery and them getting a proper balance charge each time they are charged I will get 2-3 times the life from the pack. I don;t use my cordless tools as much as I used to, but I was always quite concious about not discharging my batterys too far, kepping them inside during winter/freezing weather/etc... and the batteries never lasted long for me, 4 batteries in 3 years is not acceptable IMO.


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## delus

One of my 18V LXT batteries went dead. At least it will not charge on a factory charger. I lined them all up, and it turns out I have exactly 11 of them, and all the rest take a charge. Then I noticed they all have a little star on the sticker, except for two. The dead one does not have a star. Next i looked at the makita website and found this.
http://www.makitatools.com/en-us/Modules/Tools/LXTAdvantage/StarProtection.aspx This star identifies the "new" type of battery.
Makita does not mention anything about cell balancing, but looking at clues in this thread, I'm 90% sure that the star means it includes balancing. 
Most of my tools also have a star where the battery is attached.
I also have five chargers, four of the older green ones, and one of the new smaller black-plastic design. They all have a star except for my oldest green charger. 
I had a couple of drills before i got into Makita in a big way, at Xmas 2010. So i think these star batteries started to become available around the same time this thread started, late 2010.

In any case, I still want to get that one dead battery working again. I'm drawn to the quick and easy, but dirty way. Quote from "JCSSJ2". (A lot of people with low post counts in this thread.)


jcssj2 said:


> For anyone interested, I had the internal pc board brick 3 of my LXT batteries. The interesting part is the cells aren't bad. No need to replace any of them. The problem is they won't charge in the factory charger ever again. To my understanding if you try to charge with the makita charger 3 times the battery will never charge in the makita charger again. These batteries take a charge and hold a charge and are usable. They just won't charge because of the internal chip. For future reference if anybody has a dead battery, take a good battery and use jumpers from the good battery to the bad one and they will take a charge. I just use a couple of 10mm or (1/4" if they aren't 2 thick) washers slipped in the clips and alligator clips to jump. It takes only about 5 minutes to recharge them like this. They will read 17+ volts that quick and will charge in the factory charger then.



If my other non-star battery is wasted it's not a giant loss, i figure it doesn't have much time left anyway.
My question is.. I reverse the polarities right? I'll use the two non-star batteries and wire them positive on the good battery - to negative on the bad battery, is this correct? 
I'll wear a full face shield and some other rubber protective equipment designed for working with acid. And I'll do it outdoors on concrete, with a fire extinguisher ready.


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## ginbot86

delus said:


> My question is.. I reverse the polarities right? I'll use the two non-star batteries and wire them positive on the good battery - to negative on the bad battery, is this correct?



No! You don't want to reverse the polarity as you'll get a short circuit.  If you want to charge this way, connect all + to +, and all - to -.


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## woodworking

hey everyone. I came across his forum when looking to replace 2 old 18v li-ion batteries, these are about 5 yrs old and age has gotten the better of them. I'm wondering if these have the chip in them, I don't think they do. I believe Milwaukee has a battery that is inter changeable, although I don't know how good it is for the battery. The way I see it, instead of spending $180 on new batteries, I'm going to buy a new tool set probably Milwaukee, replacing the 3 Makita tools I have. Any thoughts on a good replacement brand? Has anyone tried switching battery brands?


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## gibberoo

Hi all I'm new to all this,my query is that I rebuilt 1 of my batteries replacing some dead cells and fitted a new pcb board now when I put it on the charger it just flashes red as though the battery temp is to high sadly not charging but when I put the battery in one of my tools it runs fine I'm stumped


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## Etsu

woodworking said:


> hey everyone. I came across his forum when looking to replace 2 old 18v li-ion batteries, these are about 5 yrs old and age has gotten the better of them. I'm wondering if these have the chip in them, I don't think they do. I believe Milwaukee has a battery that is inter changeable, although I don't know how good it is for the battery. The way I see it, instead of spending $180 on new batteries, I'm going to buy a new tool set probably Milwaukee, replacing the 3 Makita tools I have. Any thoughts on a good replacement brand? Has anyone tried switching battery brands?



I use Dewalt cordless tools, with NiCad batteries. LiIon have never served me well when it comes to longevity. When I can avoid them, I do.


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## elduderino970

gibberoo said:


> Hi all I'm new to all this,my query is that I rebuilt 1 of my batteries replacing some dead cells and fitted a new pcb board now when I put it on the charger it just flashes red as though the battery temp is to high sadly not charging but when I put the battery in one of my tools it runs fine I'm stumped



I'm no expert but here are my thoughts on your question.
I assume that you have read that the pcb will brick itself on the third occurence if you try to charge when in error condition.
You might try checking the voltage of each set of cells in the pack to make sure they are close. If not, try charging just that set to get them close to the rest. This process would take some sort of li ion or lipo charger.
If all else fails, you can use a hobby charger, a voltage monitor, and make a balance connector to attach to the pack. See my posts above for more info.
HTH
John


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## bwDraco

Sorry if I'm reviving an old thread, but I use DeWalt 20V Max and can definitely state that DeWalt does perform cell balancing on their batteries. With Makita pushing lightning-fast (9 amp!) charging speeds, it's a bit disappointing to find that their battery control circuitry draws on only one cell, causing the whole pack to fail prematurely if it isn't used regularly. It's also an odd decision to disable the entire pack on three failed charge attempts—I understand the safety concern, but this isn't necessary if the battery can simply communicate to the tool/charger that one or more cells have failed. Unfortunately, this seems to be necessary because not all Makita tools can digitally communicate with their batteries, and not all batteries can communicate with the tool; older Makita 18V LXT tools and batteries without a star mark don't have the company's "STAR Protection Computer Controls". (I'm not here to bash Makita—they make great tools, but are a bit backwards in their battery design. Then again, they were the first to introduce an all-lithium 18V battery platform. The 18V LXT platform dates back to 2005, so their initial implementation was apparently missing the digital communication features new batteries and tools have.)

The DeWalt battery has B+ and B- connectors where the main 18-20V output is supplied to the tool. However, there's a total of eight connectors on the battery, four of which are specifically for cell balancing. Along with the B+ and B- connectors, the C1-C4 contacts are hooked up to the individual cells: from negative to positive, B- to C1 for the first cell, C1 to C2 for the second cell, C2 to C3 for the third cell, C3 to C4 for the fourth cell, and C4 to B+ for the fifth cell. They are hooked up internally in series and all of the pins are present on the charger, which performs the cell balancing. Fresh off the charger, each cell should have a voltage of about 4.1 V for a total voltage of 20.5 V. (Side note: The remaining two pins on the battery are marked ID and TH. I'm guessing ID is to identify the battery type, perhaps for communication between the battery and tool/charger to distinguish between 20V Max and the nearly electrically compatible 12V Max, which might simply not have pins for C3 and C4. The TH contact is probably for temperature sensing. My DeWalt DCD790 drill has pins for B+, B-, TH, and C3, but I'm don't know why it needs the C3 contact.)

What I'd like to know is whether Makita has these cell-balancing contacts on their 18V LXT batteries. Can someone check one of their Makita batteries to find out?

--DragonLord

*Edit:* So I read through the thread again, and it seems that the newer batteries and chargers do have cell-balancing connectors. If only Makita would fix the single-cell discharge issue...



torukmakto4 said:


> I use quite a number of Sanyo UR18650SAX. Only 1300mAh, but 25A continuous rated and cheap, they make good robust high performance RC-type packs for low cost. Sanyo also has the successor WX and RX, 1500 and 2000mAh 20A cont.



I believe DeWalt uses the Sanyo (now Panasonic) UR18650RX cells for their 20V Max XR 2 Ah and 4 Ah batteries. These cells are rated for 22 A maximum discharge rate, so the DCB204 premium 4 Ah battery (which has 10 cells in 5S2P) can reliably supply up to 44 amps of current. Not sure what the upcoming DCB205 5 Ah batteries will use, though.


----------



## ddwaner

I have 2 BL1830 Battery packs that after 2 years of easy use both went bad within 2 weeks time. I couldn't get the packs open with the screws so I drilled both to open them. In both packs duel battery cell set #4 (4th one in from +) were BAD. I tried to charge even individual cells and found from about 0VDC they would charge to about 3 volts then drop and heat! I removed 2 good battery's from one of the packs to make 1 and did. I slow balanced all 5 pairs 2 places past the (3.012) and sometimes 3 past the (.), of the low battery set voltage and tried to charge with the Makita charger made for the tool set which was in my case a Impact driver and Drill set. I had already passed the 3 fails light so again I got the same fail'd battery condition. The battery's I have were made from the positive terminal on the board, 3 sets of 2 cells then were tapped to the circuit board and from there 2 sets of 2 cells to the negitive terminal to the board. I charged the battery pack with a Lithium Ion charger but had a limitation of 3 or 2 cells so I charged the 3 cell set first then the 2 cell set till the charger show'd ready to use, the balance was ok across individual cell sets and found that the battery packs ran the tools ok. I intend to buy a iMax B6 OEM Battery Balance Charger for 1-6 cell Lipo, Li-io, LiFe from Amazon for about $22.08 and add a 5 cell balance terminal to the battery.

I have been flying RC helicopters and airplanes since long before battery's were considered even possible, I started using battery's to fly when the LiPo's were starting. The way these packs were made is NOT my idea of how to charge this type of battery pack. The cells should have 5 tap points and be balanced in individual pairs during the charge. The circuit board in these battery packs have a lot of parts on them and even more on the bottom side of the board including 1 very large 30+ legged chip. Looks like Makita has made good tools but kept the weakest link where they could profit the most with an excuse. A new Makita battery at HomeD is about $99.99 and I did buy ( 1 ) and it works. I will probably buy a cheep 18V replacement battery when I buy the charger from Amazon if for no other reason for some replacement battery's for the Makita packs I have.

Makita you :devil:.


----------



## iv2013

Today I tried using my Makita tools but both batteries were drained from not being used over the last 3 months. I put both on the charger and had the red/green flashing lights on the charger. Looked up the info on this forum and decided I would call the local Makita service centre before attempting to make repairs my self. At first they told me that my batteries were defective and that I would have to buy new ones since they were past the 1 year warranty, but when I told them that they had less than 150 charges (as mentioned on this forum) and that Makita should replace them, they told me to bring them in. I went the same day and had them both replaced, no questions asked, free of charge. The guy did put them on a charger to verify that there were indeed less than 150 charges on them.

Just want say thanks for the useful info, this forum has saved a bunch of us from buying new batteries!

p.s. Pretty disappointing that the guy was going to force me to buy new batteries before admitting that Makita replaces all batteries that have had less than 150 charges regardless of warranty. I bet a lot of people get caught on this.


----------



## NotMyCupOfTea

iv2013 said:


> Today I tried using my Makita tools but both batteries were drained from not being used over the last 3 months. I put both on the charger and had the red/green flashing lights on the charger. Looked up the info on this forum and decided I would call the local Makita service centre before attempting to make repairs my self. At first they told me that my batteries were defective and that I would have to buy new ones since they were past the 1 year warranty, but when I told them that they had less than 150 charges (as mentioned on this forum) and that Makita should replace them, they told me to bring them in. I went the same day and had them both replaced, no questions asked, free of charge. The guy did put them on a charger to verify that there were indeed less than 150 charges on them.
> 
> Just want say thanks for the useful info, this forum has saved a bunch of us from buying new batteries!
> 
> p.s. Pretty disappointing that the guy was going to force me to buy new batteries before admitting that Makita replaces all batteries that have had less than 150 charges regardless of warranty. I bet a lot of people get caught on this.



Today I went to my local Makita service center and the guy said Makita is no longer replacing batteries after he tested my 2 at 37, and 39 charges. This is all so arbitrary to me, is there an official statement by Makita saying it will replace batteries under 150 charges? 

Anyway, later I did call Makita direct, and after telling them how disappointed I was they said for me to mail it to them and they'd probably replace the batteries.
Side note: I still have a Makita battery from over 20 years ago, IT STILL CHARGES, doesn't last long, at all, but hey it charges :rock:


----------



## delus

Makita BL-1840 with FOUR amp-hours has been available in the USA for a few months now.  $130. It is said to contain 10 of the 2Ah 18650 cells (most likely provided by Sony). Same exact shape and weight as the previous BL1830 3Ah model with the 1.5Ah cells.  

Makita BL-1850 with FIVE amp-hours is on the way... I can't find it anywhere that accepts American Dollars. Here is makita australia...http://http://www.makita.com.au/products/lithium-ion/item/bl1850-18v-li-ion-battery

Some questions about tool compatibility are evident, but ToolGuyD has asked Makita UK, and says that the star logo, and/or a yellow plastic part at the battery connector plate, indicates your tool is compatible with the new batteries.
http://toolguyd.com/makita-18v-lxt-5-0ah-battery/

http://toolguyd.com/makita-18v-lxt-tools-and-bl1840-battery-compatibility/


----------



## KDM

Is there a certain test to tell the amount of charge cycles? Does Makita have to perform the test?


----------



## delus

Yes, Makita service centers have a special charger/computer that will read charge cycles and some other info from the battery's chip.

Find your closest authorized service center here. http://www.makita.com/en-us/Modules/Service/ServiceCenters.aspx


----------



## jackbombay

delus said:


> This star identifies the "new" type of battery.
> Makita does not mention anything about cell balancing, but looking at clues in this thread, I'm 90% sure that the star means it includes balancing.



Wishful thinking IMO.

Why would they kill their own cash cow? This is Murrica, the stock holders demand profits!



I now have 4 makita batteries that I have opened and re-engineered so they are for sure getting balanced charged with a "hobby charger", they all run like world champions, and I charge them at a 3 amp charge rate instead of 6-9 amps as the factory charger does which in itself is terrible for the batteries.


I have plenty of friends that use makita tools regularly and they still go through batteries same as they ever did despite the introduction of the packs/tools with the stars on them, fwiw.


----------



## jackbombay

There is nothing in the "star battery pack" literature that indicates those packs are balanced charged,

http://www.makitatools.com/en-us/Modules/Tools/LXTAdvantage/StarProtection.aspx


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## Bucks

Just making sure I am in the correct thread. I have a DC18RA charger for Makita ion 18v batteries. I purchase 2 years ago and I use for home use. Today went to charge battery. Once on charger, it flashes green and then after 15 seconds, turns red and shuts down. Tried 2nd battery, same thing. I tried searching similar problem but found nothing. Any help would be much appreciated.


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## alpg88

jackbombay said:


> There is nothing in the "star battery pack" literature that indicates those packs are balanced charged,
> 
> http://www.makitatools.com/en-us/Modules/Tools/LXTAdvantage/StarProtection.aspx



did you really want to find in depth details on consumer aimed publication??? you wont find such details there, but you are not far off, however. 

pack soc is monitored by last cell, when it gets fully charged, than charging stops, other cells may overcharge a bit, that is why they get really hot during charging, and thus the fan inside the charger, and gaps between cells, so the air circulates in the pack. we had another thread about it, with detailed pics of the board and pack. when I took mine apart, shrinkwrap was mostly melted, but pack worked just as good as the first day I got it.


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## ifixthings

First, I don't do many post to forums just read, read, read and learn, learn learn. But this could help some folks so...


Here is some information on how to possibly reset the charging chip in the Makita 18 Volt 3.0 AH (OLD STYLE) that WORKED FOR ME... Your mileage may very...


If you don't want details and background, skip down to CHARGING TEST.




Some history.


I purchased my Makita 18 Volt LXT 4 tool kit in Nov. 2006. It came with 2 - 3.0 AH batteries. I purchase 1 additional 3.0 battery and 2 - 1.5 AH batteries a few months later. (NOTE: In order to use the 1.5 HA batteries, I had to cut the stop lug off of each tool so that these smaller batteries would work... If you every tried to use a 1.5 AH battery in a tool designed for a 3.0 battery, you know what I'm talking about...)


In 2008, I had 1 of the 3.0 batteries lock up and 1 of the 1.5 lock up. Over the the years I would keep trying to charge them but the Makita DC18SC factory charger refuse to allow these batteries to be charged. To this day, 2 of the 3.0 AH batteries and the 1.5 AH battery are still very usable and are functioning. Since the time of the kit purchase, at least one or more of the tools in the kit are used about every week.


FYI, I have rebuilt many of my Dewalt 18 volt Ni-Cad batteries using new Ryobi 18 Ni-Cad battery packs and other Ni-Cad tool packs with Ni-MH where possible.


1.5 AH Pack Disassembly.


About a month ago, I was in Harbor Freight and found the screw driver bits (a pack of long security bits with many sizes) that are required to remove the 4 screws on the bottom of the Makita battery packs. So last week I finally got around to disassembling the Makita 1.5 AH pack. It was much more complex than any of the Ni-Cad packs I have seen but thought "No Guts, No Glory" and total disassembled the pack which contained 5 - 18650 batteries. 1 of the batteries tested at 4 volts, 3 @ 3.8 and 1 @ 0 volts. The one @ 0 volts also had some leakage. I was able to top off the one 4 volt battery using my Nitecore charger (used for my flashlights of course!) however, the 3 - 3.8 volts single cells charge VERY slowly and would keep resetting the Nitecore charger... I decided that I would keep the one battery that started out at 4 volts for future use and set aside the 3 other batteries from that pack for additional testing and charge cycling later.


3.0 AH Pack Disassembly.


Next, I disassembled the 3.0 HA pack. This time with the thought of just changing out any bad cells and reassemble the pack so I could use it again. So, like others have found in this thread, the first upper and lower pair of cells were bad... 1 @ 0 volts and 1 @ -.05 volts (it was reverse charged!). The other 8 cells were all between 3.6 and 3.8 volts. Please remember, these locked up packs have been sitting in the garage since 2008! I was impressed!


Detail Disassembly.


When disassembling this pack I carefully un-soldered the one heavy black wire going from the circuit board to the front set of batteries (looking at the battery with the WHITE RELEASE tab in front of you, it would be the black wire on the top left - SEE PICTURES) and then the tab the goes up from the bottom into the circuit board's charging lug from the connections on the right side of the battery pack. Next, I removed the screw that holds the circuit board to the top of the pack and lifted the circuit board to the side gently. (I left the 2 green and 2 black wires attached.)


Now the hard part! Getting the 10 cell pack out of the case took some time because I didn't want to damage anything since my plan was to reuse this puppy. The top black plastic piece under the circuit board came off easy enough. Next the cells had to be removed. I just keep prying with a straight blade screw driver all around the 10 cell pack until it finally popped out! In the process of this I did tear the green plastic on one of the cells. When I reassembled the cells, I applied some clear silicone to the cell with the rip in the plastic.


Next, I un-soldered the front 2 cells that were bad after remove the paper covering each side of the cells Positive & Negative contacts. I charged the remaining 8 batteries up to a little over 16 volts (they were still all soldered together) . I replace them with good cells from a Ridgid Lithium-Ion pack that were good. But first I charged the Ridgid cells to 4.2 volts each. Next, I resoldered the 2 Ridgid batteries back into where they belong and applied electrical tape to the positive and negative contact where the paper use to be. Next, I put everything back together. Of course I soldered the heavy black wire and tab inserted into the circuit board too! (see photo.)


Once assembled the voltage was 21 volts! Ah, good as new! Tested it in a tool and it worked great! Thought I was done...




Charging Test.


I put the reconstructed pack into the Makita charger and BAM! IT FAILED!!! The red and green lights flashed to say that the pack was still broken!! WHAT? All this work and no pack!.. So, The next day I called Makita Service center to find out how to reset the internal battery circuit board. After talking to a few techs, I finally got the answer...


To learn more, just PalPay me $10.00 to .... Just kidding...


As it turns out Makita only would say they don't service batteries! Like their tools, hate they help!


Once again, I put the battery in the charger and it still gave me the lockup / repair message.


Wait For It...


So, I unplugged the charger and let the reconstructed battery both sit in the garage overnight (it was in the high fifties and low sixties that night) for almost 24 hours.


The next evening, I took the reconstruct battery and put it in the circular saw and ran it a few minutes to get the charge down. WITH THE CHARGER UNPLUGGED, I inserted the reconstructed battery and plugged the charger in. BAM! THE CHARGER STARTED TO AND COMPLETED CHARGING THE RECONSTRUCTED BATTERY PACK!!!!!!!!!!!!!!!!!!!!! 


NO MORE REPAIR CODES!!!!!!!!!!!!! (SEE PICTURES)


Now this worked for me using the first gen batteries (Non-Star) and older charger. Your results could be different... Don't Flame or Blame me if it doesn't work for you.


Final Thought.


I do not know for sure why this pack reset. I think it was one of two things or a combination of the two.


1. The reconstructed pack sat over night. This new addition voltage may have told the circuit board that the pack was fixed.


2. The charger was left unplugged over night. Maybe it is the charger that remembers the bad battery - OR-


3. By inserting the battery into the UNPLUGGED charger first, then plugging the charger in, it caused the battery circuit board to "reboot" and check the battery voltage BEFORE giving the Fail message.


I know this is long (I guess that is why I don't do many posts...) but I hope it helps someone else using Makita tools.


Thanks for reading and Please post if it works for you or even if it doesn't!


----------



## pipster55

ifixthings

It has taken some serious searching but finding your post has answered questions that I have had for some time concerning Makita's internal battery circuit board and a possible work around. Others have suggested hacking the board which I am okay with but I am working towards a fix for those who don't want to monitor anything, just plug and play, safe.


It's been a few months since your posting. How is your repair standing up to the test of time?


Thanks for the write-up. I shall make the attempt.


----------



## ifixthings

pipster55 said:


> ifixthings
> 
> It has taken some serious searching but finding your post has answered questions that I have had for some time concerning Makita's internal battery circuit board and a possible work around. Others have suggested hacking the board which I am okay with but I am working towards a fix for those who don't want to monitor anything, just plug and play, safe.
> 
> 
> It's been a few months since your posting. How is your repair standing up to the test of time?
> 
> 
> Thanks for the write-up. I shall make the attempt.





Update...

The rebuilt pack lasted and was rechargeable until the first part of Oct. 2015. At that time, it once again started to give the charging error message. I have not had a chance to disassemble the pack yet, but suspect that maybe another cell went bad. Will provide another update concerning that pack once I get a chance to disassemble and test it again.

Keep us posted on your progress too!


----------



## wookey

Hi people, 

I am very interested in Makita's battery design foibles as I have 14 of the 14.4V packs (BL1430). Like mucek we use them for caving. The drill system is great except for the idiotic software in the battery packs, which means that 6 out of our 14 packs now have to be charged on an RC charger instead of the Makita ones (which is fine but slower, and more complicated for our users).

I see that mucek hasn't made any published progress since Oct 2013. Has anyone else? Battery vendors are selling replacement packs so they must have worked out enough of the protocol to make batts that charge. I have just bought one to see how it holds up (and what I can discover).

For our use-case the batts get well-used use (charged/discharged every day or 3) for a month and then sit around all year. I give them all a charge/discharge test each year and store them at 40% charge to improve battery life. We seem to get an average of 3% capacity degredation each year, which seems acceptable.

I have taken them to bits and rebuilt some packs by taking 'dead' 18V packs, stripping off one cell pair and re-assembling. The 14.4V packs are not even balanced by the annoying charge circuit. It only has a sense wire to the middle of the pack - so they presumably check '1st two cells' and 'other two cells', but that's all. Pretty shoddy. The 18V donor packs I have do at least have balance wires. 

The best plan seems to be to bin the stupid monitoring circuit, repurpose the yellow connector as a balance connector, and use a sensible charger (I have an Accucel 6). But this is a faff, and it would be nice to work out how to reprogram the packs to stop being so dumb. I have the tech but not enough time for the reverse engineering.

On this point, does anyone know the type of that yellow connector - can I buy a mating half (as opposed to canibalising makita chargers).

Also does anyone know of a good balancing lion charger that does the job of the accucel 6, but can be programmed to 'just start, for 4 cells' on battery insertion so there is no fancy button-pushing to be done (this confuses our less-technical users, and is not needed of rigging up a single-purpose chargeer).

Anyway, if anyone (mucek?) wants to collaborate further on getting to the bottom of this, I am quite keen. Just heading off to expo again for this year, back in 3.5 weeks. With more data and probably some more 'bricked' batteries.


----------



## bwDraco

Welcome to CPF! :welcome:

Unfortunately, I don't have any Makita tools or batteries so I wouldn't be able to help you here. I'm rather surprised that Makita has not resolved this design issue after all these years. Can't they just wire the monitoring circuit to each and all of the cells in parallel so that it draws upon them evenly?

I've had my DeWalt 20V MAX batteries for more than two years with absolutely no trouble.

_Draco_


----------



## finn

The new 18xx batteries have led gauges, and model numbers end in "B". You can see one disassembled half way through this:
https://www.youtube.com/watch?v=JXf6yHIKdvQ

They at least appear to be fully balanced now.


----------



## simsinater

mucek said:


> Huh, and some more words about hacking the Makita's BMS unit ...
> 
> Currently I am so busy, that I didn't make any significant improvement in the protocol decoding. However, I have designed a programmable 6S BMS with proper data output, which will be (later) able to replace (locked) original Makita's BMS in 18 V batteries. Basic BMS functions are already working, but I have to dig deeper in order to persuade Makita charger to give me some power ...
> 
> Regards,
> Gregor




I'm currently eagerly waiting on parts and tools so that I can start rebuilding my Makita batteries. So glad I found this thread! Any updates on the hacking?


----------



## delus

*Makita "Refreshing" charger.*

This morning I was looking at some makita chainsaws online... need to complete my collection.
Noticed something very refreshing. The Makita ADP03 (SKU 193681-B) MAKSTAR Refreshing Battery Adapter. 
Don't know much about it yet. Don't know how long it's been available to the public. it doesn't show up in Makita's "New Products" website or catalog. you can find it at MakitaUSA.com with a search for "refreshing". 
Has anybody seen this thing before?


It appears that it WILL re-animate dead Makita batt packs. Maybe. Pasted from a seller:
This Battery Charger accessory helps restore inactive MAKSTAR&trade Ni-MH batteries that have been inactivated. Refreshing batteries allows you to stretch the overall battery life of your batteries which will save you from having to replace your old batteries. 

Works with Makita battery chargers DC24SA, DC14SA,DC18RA or DC18SC
Conditions battery cells that have been inactivated for extended battery life
Refreshes batteries in as little as 40 minutes
Can automatically detect batteries that need to be refreshed
Accessory??? This had me wondering. Then I found a manual. https://www.manualslib.com/manual/1237881/Makita-Adp03.html?page=2#manual




Page 2 has a very revealing diagram! AHAH! it's an adapter. It is not a charger by itself. It fits on top of an existing charger. It has no cord.
The Makita website shows the right side, but Amazon has a picture where you can see a curved edge on the left side of it. Now it makes sense.
Page 5 of the manual says "• Use this adapter with Makita battery charger DC14SC, DC14SA, DC18SC, DC24SA or DC24SC." ... Ok, i definitely have one of those.
Also talks of THREE flashing lights and the "Refreshing Button". Also "conditioning" and "refreshing" appear to be two separate things.
It can indicate a "capacity" of less than 40% as a worn out battery. Hmm.. never seen the word "capacity" used like this before.
Page 6 of the manual mentions compatibility with older NiMh, and the BL 1830, but not 1840 or 1850. So the refresh adapter can't be all that new. It's been around awhile.
Pages 7 and 8 show detailed usage instructions, but veer a bit into Chinglish (or should I say Japglish?) Possible fourteen hour conditioning time?

I want, I want, I want! Last time I counted I had 22 of the 18xx packs. Four of them won't charge. One of the four has been sitting on a shelf at least five years. One of the four is a BL1850. 
But I'm gonna hold off a couple days, want to find a little more info. Will try some euro and asian sites.


Edit: corrected NiCad to NiMh


----------



## delus

*Re: Makita "Refreshing" charger.*

Quoting myself from over four years ago… 


delus said:


> Yes, Makita service centers have a special charger/computer that will read charge cycles and some other info from the battery's chip.


I knew I had seen something like this through the service center’s doorway, but couldn’t get a straight answer to my questions. Then when I came back at a later date, they acted like i was stupid. (didn’t have to go to acting school)

The date on this parts schematic shows the refresher has been a thing since at least 2010 http://media.toolpartspro.com/image/ADP03/ADP03-Makita-PB.pdf
They are just now making the device available to the public? Is that what’s happening here? If so, it seems less than righteous of Makita to withhold it for eight long years while people are throwing away batteries, and of course buying new.


There are a total of five available from three sellers on fleebay. They offer the device at a 300% markup over the price I see at amazon. Are they asking ridiculous prices because they are the first to have a new item? Seems like it. You can see the auction “revision summary” and the oldest date I see there is July 10, 2018, so it’s been out in the wild at least that long.


Oh! My! Gawd!
It said only one left on amazon, so I ordered at $91.71…. Went back to the page a few minutes later and now it’s out of stock, and the price is $247.10


----------



## Gauss163

*Re: Makita "Refreshing" charger.*



delus said:


> [...] There are a total of five available from three sellers on fleebay. They offer the device at a 300% markup over the price I see at amazon. Are they asking ridiculous prices because they are the first to have a new item? Seems like it. You can see the auction “revision summary” and the oldest date I see there is July 10, 2018, so it’s been out in the wild at least that long [...]



Some eBay sellers appear to use automated software that adjusts their pricing against competitors - including Amazon, e.g. when Amazon prices drop/rise so too will the eBay prices. But often this doesn't kick in right away for new products.

You can track prices and find historical price charts for Amazon products on camelcamelcamel.com I don't know of anything that works for both eBay _and _Amazon. Anyone?


----------



## delus

*Re: Makita "Refreshing" charger.*

Looking at the website provided by Gauss163 (Thanks), it seems the item first appeared on amazon in March 2014. Starting at about $160, it has usually been over $200, and is currently at it's highest price ever. It looks like one lucky guy got one for $40.85. Mine was $91.71 which was a little higher than the price I had seen early that morning.

https://camelcamelcamel.com/Makita-193681-8-Refreshing-Adapter/product/B0007ZKG0W?context=search

I wonder exactly how many units they have sold in that time, and why I have never heard of it. In any case, I knew I was saving that free trial of "Prime" for a reason, will it arrive saturday?

Here, the ADP03 is shown along with another charger, and some computer cables. 
https://www.bidspotter.co.uk/en-gb/...0196/lot-ea92c573-f191-4dfb-8e92-a70c00fff499
One ebay seller has the six photos of the item from all sides. You can see on the back, what looks like a cover over the port. That's what i saw through the service center door. A charger with the adapter attached, and a battery on top of that. It was connected to a computer. Is there an app for that?


----------



## Gauss163

*Re: Makita "Refreshing" charger.*

^^^ Those price drops from over $200 to under $40 are typically done by automated software. If you register a price alert on camel^3 then they'll send you an email when the price drops into your desired range. If there's no rush and it's not a high-demand item you can often get it at large discount. I do that on eBay and usually get such low-demand items for 5 to 10 times less than street price. On eBay you can use their "Favorite Searches" to get email alerts.


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## delus

*Re: Makita "Refreshing" charger.*

Some things i found in my continuing investigation:

At the Makita-UK link below you will see a picture of the Makita 194918-6 Battery Checker System. Apparently the ADP03 Refresher is one part of that system, shown on the lower left. MakitaUSA lists that part number 194918-6 as a completely different item.
http://www.makitauk.com/accessories/batteries/adaptors/194918-6-battery-checker.html


For service and Workshop use.
Makstar Battery Checker detects the number of charges and diagnoses the condition of the Ni-MH/Li-ion batteries. This equipment reads the history of the battery from the built-in CPU, finds how the operator treated the battery and gives the right advice to maximize the life of the battery.
It can also be used for simple-checking conventional Makita batteries, using the adapter which is included with the battery checker.
So it’s the battery CHECKER that reads the battery’s chip and connects to a PC, and the REFRESHER is a separate item that does the charging.
By “conventional” do they mean older 18V batteries without the star? Or does it mean a different adapter (ADP01 or ADP02?) for the NiMH packs?
The big question is: Can it reset the chip inside packs that have been bricked by other chargers? I don’t think that the refresher can do that. Probably only the checker can do that.


A french listing has the longest list of ADP03 compatible chargers.
Chargeurs compatibles: DC18RA, DC18RC, DC18SD, DC18SE, DC24WA, DC24SC

The ADP03 has been listed as an “Optional Accessory” in the user manuals of some Makita battery chargers, since at least June 2014. 
“When used in conjunction with charging adapter ADP03 this charger offers also the possibility of charging Ni-MH slide on batteries of 9.6V to 24V batteries”

While the refresher has been part of the checker system since March 2010, I have seen no evidence of the refresher being offered for sale as a separate item before June 2018.


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## delus

*Re: Makita "Refreshing" charger.*

Well, the refresher was delivered a few minutes before noon. (On a Sunday!) 
First I did a refresh charge on a relatively new, known good battery. It took almost six hours to finish. At the end I got the three lights on the lower panel that indicate "Yes, this is a relatively new battery with at least 80 percent of it's stated capacity remaining." Excellent!
Next, I tried to revive all four of my dead battery packs. No-Go. 
I seriously doubt the full "Battery Checker System" can revive them either. In retrospect, the slim hope I held that these dead packs could be revived, was foolish. If it was possible to do, we would have stories of people going into service centers with dead packs and coming out with revived packs. It does not happen. Once they are dead, they are dead.
Still, the refreshing adapter is a good investment for me, as I still have another seventeen packs to refresh, it should take a week or more! I got the chainsaw deal with the double-charger and four 5.0 batteries, so I'll be back up to 22 good packs. And no end in sight.

Would a full formal review of the refreshing adapter be appreciated and appropriate at a flashlight forum? I tried to review a light a few years ago and it turned out not-so-good. Since then I have been itching to redeem myself with some better information.


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## nl635

Hi guys,

I have one makita 1830B li-ion battery, which is gonna die very soon(it has 3y of everyday use now, and has very small capacity...), but charge chip in battery is still unlocked

Is it possible to change just cells? Will be this original circuit board working with them?


thanks


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## delus

nl635, Makita 18V lithium battery packs are not designed to be servicable. It's nearly impossible to get one apart and then back together. Take a look at this video from a veteran tool repair? man. https://www.youtube.com/watch?v=DG2KHJILDzo And that's the older design that's easier to get into.
With three years of daily charges, you got your money's worth out of your pack, that's a thousand charges. It's capacity is probably severely diminished. When it completely dies it will most likely die suddenly, meaning you'll suddenly not be able to work. It's best if you get your new one before you need it. I recommend staying with genuine Makita. I see two genuine 1830's for $89. But you can get 1840, 1850 or even 1860 which will give you more work between charges. Most locations offer a pre-holiday Makita sale right now, $25 off any order over $100 but batteries (by themselves) may or may not be eligible.

Looking around... I did see something new! Makita now offers a 1830 pack that is advertised to work at -3 Fahrenheit! No doubt uses the same chemistry that Milwaukee uses in their packs.


Also, I did a review of the Makita ADP03 Refreshing Adapter, here it is. https://www.candlepowerforums.com/vb/showthread.php?453112-Makita-ADP03-Refreshing-Adapter
AFAIK it's the only review anywhere.
What's the verdict? Probably pretty good for old NiMH packs, but almost completely useless for lithium BL-18XX packs.


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## fpdragon

Hello, I read through this thread 2 times and I still don't get it how these batteries are working.

Here is what I know:

Makita batteries are 5s2p (5 cells in series)

Connectors:
2 very big -> + and - (18V)
1 medium -> temperature sensor
yellow 7 pin connector -> ??? id? resistor? balance leads?

I do know that there are battery packs that have no balance circuit included. That’s maybe ok as long as they get balance charged.
But there are also aftermarket packs that definitely have no possibility to balance cells since not all cell potentials are soldered with the circuit board. What?!


My plan is to use two 18V battery packs in series (10s) and for this purpose I want to balance all cells of both packs. The question is, can I access each cell from the outside of the packs or do I have to modify the packs with an additional 6pin/4pin connector? First, I was expecting that the yellow 7pin connector is made for balancing but on my aftermarket pack these pins have definitely no connection to the other cell points. Maybe this is just because they are crap.
I have a 6.5A quick charger and also had a big surprise. Maybe it is just charging all cells in series or it charges each cell balanced. I don’t know but I just noticed that the charger has only metal connections on Pack minus, TH and the yellow 7 pin but NO PACK PLUS connection! So maybe this charger is balance charging since it does not have a + connection? Or the + connection is somewhere on the yellow connector too? Or the TH pin is used and conducts to battery + 18V just over a temperature switch in series?
In theory I would expect and need the following voltages:
0V/- … Pack –
3.6V/Cell1+ … maybe yellow connector?
7.2V/Cell2+ … maybe yellow connector?
10.8V/Cell3+ … maybe yellow connector?
14.4V/Cell4+ … maybe yellow connector?
18V/+/Cell5+ … maybe yellow connector? / Pack +
Is there a pinout of the yellow connector somewhere? Can I balance the pack with the connector?


I found the following site:
http://makita18vmod.blogspot.com/2013/07/aftermarket-charger.html
where the blogger repurposed the yellow connector for using it as balance leads only. This means that after his hack the battery is not compatible with common Makita chargers any more. And still I don’t get it that this yellow connector should be just used for this silly battery id and this useless fail counter interface. I can’t believe that Makita had money to design this but forgot of some basic balance leads. 
I also think that it is very risky to charge 5s2p Lion packs with 6.5A without balancing. The risk of overcharging a cell is very high.
Hope someone can help.


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## sbj

I also have a couple of 18V packs. They really don't have any balancer connections!
I attached a standard 5s XT balancer connector to one pack. Primarily to be able to monitor the cells individually. This connector was already quite annoying on the outside of the battery.
That went well for a few years. There was no evidence of imbalance. Now, of all things, recently broke a pair of cells inside this pack.
I haven't gotten around to replacing the defective cells yet.

I also think it's a shame that Makita doesn't provide for balancing.
However, I have found that the cells are only fully charged up to approx. 4.05V with the original charger.
Firstly, this is good for the service life because it can be stored better. Second, there is some room for slight imbalances.

The yellow connector is primarily connected to a small circuit board in the battery that communicates with the charger.


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