# How do you pamper a NiCd battery pack?



## Turbo DV8 (Feb 2, 2010)

My cordless drill pack finally took a dump. Even from very early on, it just seemed to always be near-dead whenever I wanted to use it. I don't feel I abused it. Considering dropping $45 on a new one, but I was wondering what is the best way to use/charge a NiCd battery pack to prolong it's life. My other option is creating an 8-cell 'FrankEnloop' battery carrier and stuffing it inside and out the bottom of the old battery case. Any idea how much current a 9.6 volt drill might draw? I'm thinking I'd likely have to solder thicker gauge wires directly to the carrier contacts, instead of the thin supplied wires.


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## turbodog (Feb 2, 2010)

Turbo DV8 said:


> My cordless drill pack finally took a dump. Even from very early on, it just seemed to always be near-dead whenever I wanted to use it. I don't feel I abused it. Considering dropping $45 on a new one, but I was wondering what is the best way to use/charge a NiCd battery pack to prolong it's life. My other option is creating an 8-cell 'FrankEnloop' battery carrier and stuffing it inside and out the bottom of the old battery case. Any idea how much current a 9.6 volt drill might draw? I'm thinking I'd likely have to solder thicker gauge wires directly to the carrier contacts, instead of the thin supplied wires.



A 9.6v drill can easily draw 30-40 amps at stall (full load).

You want to prolong the service life? Don't overcharge the cells and don't overdischarge the cells.

In explicit terms:

stop using drill when you notice it even beginning to slow down

do not leave on charge

do not charge when hot from using, allow to cool

do not "run all the way down" in effort to "condition/etc" cells


I've got some drill packs that I do this with and have gotten 6 years out of them with fairly heavy use.


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## 45/70 (Feb 2, 2010)

One thing I've found that seems to help large packs (large, as in many cells), is to do a 14-16hr forming charge every once in a while to balance the cells. My 9.6 Volt Makita seemed to do better doing this. I used it daily at work (as a screw gun, ever open up a Mooney for an annual inspection?) and every couple weeks, I'd bring a more or less discharged pack (I had two at a time) home on the weekend, and charge it with a wall wart charger that worked out to a 16 hr charge, instead of the 1hr charger.

The packs seemed to last around 50% longer doing this, like 3yrs instead of 2. It didn't seem to hurt anyway. And, above all, do not run the drill past when you notice it loosing power, _but_ _do run them down frequently_, for NiCd packs anyway.

Dave


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## BentHeadTX (Feb 2, 2010)

I had a Makita 9.6V NiCad last me 17 years

I would always run the battery dead before recharging. About once/twice per year I would run the battery dead in the drill then hook a light bulb to the output terminals, then let it run to dead over night. The next morning I would hook a resistor bank with amp meter to the dead battery and kill it to 0.00V and go to dead short. Then I would short out the negative to positive terminals of the battery and let it sit over night yet again. 

To get some charge into the battery, I would take a 9 volt battery and crack it across the contacts to get some voltage into it before I recharged. 

If you have a problem with a NiCad, drain it all the way down...all the way! Light bulb works wonders then use a shorting bar to get it down to 0.00 volts and let it sit over night. 

There was another trick we used to do, we called it "ride the lightning" and it involved high volts/high amp power supplies, face shields, coats and gloves. 

Just make sure the battery is a NiCad first! That stunt does not work on NiMH, Li-ion or lead acid...aim away from face, etc. 

Learned the light bulb/shorting bar trick back in the 80s working on giant NiCad packs for portable x-ray machines. Run the machine up/down the halls until the pack died, hook up light bulb bank over night, follow up with resistor box/amp meter and then... take the pack apart and short the big Saft cells with shorting bars and leave sit over night. We had to do that every 6 months to keep the 5 year battery pack warranty and never had a problem. Now with the use of high frequency generators, digital imaging and AGM cells, those days with the monster NiCad packs are over. 

We had a defib battery that was rejected by the charger/conditioner and I handed it over to the Physio Control guy for warranty. He smiled and pulled a device out of his bag and hook the battery to it. Placed the defib paddles on the device and discharged the defib into the battery. Slapped it back on the charger and it took it... ahhhhhh! Ride the lightning...get it now! (Don't try that at home, kids!) 

Good, industrial grade NiCads are TOUGH batteries! I do know that the NiMH batteries were rather wimpy when it was time to throw out the amps and you could not kill them like NiCads. Kill them for a day to keep the voltage depression away... (only applies to high quality NiCd chemistry, cheapo NiCd? I have no idea.)


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## Russel (Feb 3, 2010)

Ironically, and speaking in general terms, it is better for your Nicad battery packs if you use the heck out of them.

I've read examples of security guards that pampered their radio batterys only to have them suffer shorted usefullness, and construction workers that used and abused their batteries, having them work well for longer. 

In general terms, with Nicad batteries, it boils down to something like use it or loose it. 

Most consider one charge/discharge cycle a month minumum for maintaining Nicad batteries.

Note: Discharging a battery pack (more than one cell) to 0.0 volts is not advisable because you can cause cell reversal. In a pack with four cells in series, for example, by the time the whole battery pack is at 0.0 volts the weakest cell in the pack will actually aquire a reverse charge commonly known as cell reversal. Single Nicad cells are a different story.

http://www.batteryuniversity.com/partone-16.htm Scroll down to 'Depth of discharge' for more detailed information.


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## BentHeadTX (Feb 3, 2010)

Defib batteries are 10 NiCads in series,

If they failed on the official defib cycle, I would do the light bulb trick, dead short them for a day and throw them on a Cadex to run the .1C 16 hour break-in charge. Then I would throw them back on the "official" go/no-go cycler and that got them going over 90% of the time. 

The main problem with those batteries is they would be charged all the time causing voltage depression. I would notice with the light bulb the voltage would drop quickly, level off then start to increase voltage (and increased bulb brightness) as the crystals broke down in the mix to boost the voltage. Pretty neat to see it happen as the Fluke showed the voltage increasing under load. 

The bulb I used was a 24V 150 watt bulb and as the voltage went down, so did the current so maybe the gentle ride down to less than .1V per cell was kinder to the cells. I do know the 0V shorting trick did give a better capacity and watt hour rating than to cycle them down to 0.4V per cell then recharging. On the other hand, the reason for battery "failure" was constant charging of the batteries as they sat un-used on the crash carts. 

I can see LiFePO4 packs taking over were NiCads leave off. They give the current required, are lighter/smaller to carry, the BMS will monitor them and they cost more.


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## Turbo DV8 (Feb 4, 2010)

45/70 said:


> And, above all, do not run the drill past when you notice it loosing power, _but_ _do run them down frequently..._


 
:thinking::thinking::thinking::huh2:


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## 45/70 (Feb 4, 2010)

Turbo DV8 said:


> :thinking::thinking::thinking::huh2:



If you run the pack beyond the point where you notice the drill losing power, you run the risk of reverse charging a cell, or cells in the series pack. While NiCd cells are better at being abused in this manner than NiMH's, it can still irreversibly damage cells within the pack.

Dave


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## UserName (Feb 4, 2010)

A stubborn old man who won't listen to me, runs his drill until it won't run the screw in all the way in high gear, then shifts to low gear, and runs until it won't drive the screw in all the way in low gear, then holds down the trigger, and twists the drill like a ratchet to get the last two screws all the way run in, and then wonders why the batteries are shot to hell.

I guess that's a pretty good example of how to rape a nicd pack, then?


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## Turbo DV8 (Feb 4, 2010)

45/70 said:


> If you run the pack beyond the point where you notice the drill losing power, you run the risk of reverse charging a cell, or cells in the series pack.


 
Even from day one brand new, my main frustration with the packs on both my 9.6v DeWalt and 18v Ryobi is, even though I never drove them until they were dead, they seemed to just always be already dead or near-dead when I went to use them. I never felt I got good service out of them. Certainly not for what they ask for replacement cost.


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## 45/70 (Feb 5, 2010)

UserName said:


> A stubborn old man who won't listen to me, runs his drill until it won't run the screw in all the way in high gear, then shifts to low gear, and runs until it won't drive the screw in all the way in low gear, then holds down the trigger, and twists the drill like a ratchet to get the last two screws all the way run in, and then wonders why the batteries are shot to hell.
> 
> I guess that's a pretty good example of how to rape a nicd pack, then?



Been there, done that.  That's how I know! 



Turbo DV8 said:


> Even from day one brand new, my main frustration with the packs on both my 9.6v DeWalt and 18v Ryobi is, even though I never drove them until they were dead, they seemed to just always be already dead or near-dead when I went to use them. I never felt I got good service out of them. Certainly not for what they ask for replacement cost.



Usually when they get like that, the problem is they haven't been used enough. Through self discharge, they get crystalline growth and then suffer voltage depression which results in just what you've experienced. If you don't use them, running them near, but as I said, not completely down about once a month, this will happen.

Your choices are to just use them repeatedly over and over until they come back to life, or better, discharge them at a very slow rate with some sort of discharge setup (external to the drill) to 0.9 Volt/cell. Then you need to figure out a way to do a "forming" charge on the pack(s). For this you need to charge them at a rate of 1/10th their rated capacity for 16 hours. You may have to do this two or three times , if they are really bad. Actually if they are really really bad, it can be nearly impossible to revive them.

It's much more true in my experience anyway, that with NiCd cells or packs, you have to "use them, or loose them". NiMH's aren't so bad in this regard, but it still can happen to them as well. A lot of people will complain with both chemistries, how they charged their packs up and let them sit for three months, and now they don't work. Now you know why. 

Dave


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## Turbo DV8 (Feb 5, 2010)

45/70 said:


> Usually when they get like that, the problem is they haven't been used enough. Through self discharge, they get crystalline growth and then suffer voltage depression which results in just what you've experienced.


 
Would this make me a candidate for the newer lithium-ion packs? Do they fare better at sitting for spells? Any advantages or disadvantages to them?


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## Mr Happy (Feb 5, 2010)

Turbo DV8 said:


> Would this make me a candidate for the newer lithium-ion packs? Do they fare better at sitting for spells? Any advantages or disadvantages to them?


I think Silverfox had some advice about power tool NiCd packs in the past. As I recall he found they work best if you store them at about 1/3 charge and then charge them up fully the night before you plan to use them. 

NiCd cells basically like to be stored in a discharged state. For individual cells, some people have even recommended discharging them right down to 0 V before storage and then storing them shorted out so they remain at 0 V.


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## SilverFox (Feb 6, 2010)

Hello Tuyrbo DV8,

The Li-Ion packs haven't been out long enough to determine if they last longer than NiCd packs or not. I have had good luck with the Li-Ion packs, but then I also have good luck with my NiCd and NiMh packs too.

Tom


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## 45/70 (Feb 7, 2010)

Turbo DV8 said:


> Would this make me a candidate for the newer lithium-ion packs? Do they fare better at sitting for spells? Any advantages or disadvantages to them?



Sorry, I didn't get back to you Turbo.

That's what I'm thinking, not just for you, but myself as well. When I used my Makita, it was for work, again as a screw gun. I have Snap-on air tools for everything else. The Makita's packs would usually be run down within a couple days, sometimes both packs in a day (Re: the Mooney's), and at the very minimum, once per week. Now, that I no longer do that kind of work, I too, need a pack that can be left idle for months at a time.

As SilverFox said above, the LiIon packs haven't been around that long, but it would seem to me to be a much better and forgiving chemistry, for us anyway, regardless of whether they provide as many "work/hours" in their lifetime. Now, it's the sitting around unused, that's killing my packs.

Dave

Addendum: For those who aren't familiar with Mooney aircraft, they are general aviation aircraft that are composed of, primarily, #2 Phillips head, stainless steel screws. OK, not really but...... :naughty:


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## Turbo DV8 (Feb 7, 2010)

45/70 said:


> For those who aren't familiar with Mooney aircraft...


 
My brother started building a Teenie Two once...

Is my understanding on Li-ion correct in that deep discharges are to be avoided? My portable DVD player and GPS Li-ion batteries say it is better to keep the pack "topped off" after every use than to use to full discharge then recharge repeatedly. If this is correct, then I think Li-ion is for me and my next drill. I use it for a small job, then it sits for weeks or months. Easy for me to top off the pack after a use, if the chemistry means when I go to use it two months later it will still be pretty much full.


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## 45/70 (Feb 7, 2010)

Yes, avoiding deep discharges is highly recommended, as it will provide longer cycle life.

Most Li-Ion cells (LiCo, LiMn, and LiFe) like to be stored about half charged (ideally 40% SOC). I wouldn't see that as a problem though. Charge your drill up, use it, then preferably, check the pack voltage so as not to put it away with too little charge left. If you needed to use it right away, after it had been stored, it would work for a while, as it'd still have some charge left. The nice thing about Li-Ion's in general, is they have very low self discharge, comparable to LSD NiMH's, or better. Pulling your drill out of storage shouldn't really be a problem, unless it's been years or something. It's not a bad idea to check on the packs voltage once in a while anyway, so there shouldn't be any surprises.

One thing about Li-Ion's you have to remember though, is that they degrade whether you use them or not. Still, newer Li-Ion cells and especially the LiFe's, have longer storage life than older cells. If I could get at least 5 years out of a drill pack, I'd be ahead of where I am now. I think with proper storage voltage maintained, not keeping the drill in a hot car etc., it'd be possible to do even better than that. I have flashlight LiCo Li-Ion cells that are 5 years old, and still @ 80%+ capacity, and they get used regularly, so......

Dave


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## Mr Happy (Feb 7, 2010)

I'm not sure about the life problem with NiCd packs? For sure, the available wisdom says the quickest way to kill them is to leave them topped up on a charger all the time or to store them charged.

As long as you charge them up before use then put them away nearly discharged, and never store them on the charger cradle, the batteries should give good service. By storing them with a small amount of charge left in them you have some power available for small unexpected jobs, and if you are planning a large job you can charge them up fully before use.

Are you getting bad service by following this advice?


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## 45/70 (Feb 7, 2010)

Mr Happy said:


> As long as you charge them up before use then put them away nearly discharged, and never store them on the charger cradle, the batteries should give good service.



I'm not sure you directed this at me, or not Mr H, but where I have the problem is putting the drill away "nearly discharged". It's easy enough for me to charge the pack, or packs up, but then the drill is rarely used enough to fully, or anywhere near fully discharge the cells. That's where I have the problem anyway. The cumulative self discharge turns the cells into "crystal farms". Yeah, I know that's not the way to do it, but that's the way it ends up getting done! I may consider joining BAA (Battery Abusers Anonymous), but I think Li-ion packs would work out better in my situation, and then I wouldn't run the risk of exposing my otherwise, spotless record. 

With flashlights or handheld transceivers etc., it's not much of a problem, as they are rarely stored anyway. The Makita on the other hand probably gets used for 5-10 minutes, two or three times a year, anymore.

Dave


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## Mr Happy (Feb 7, 2010)

45/70 said:


> I'm not sure you directed this at me, or not Mr H, but where I have the problem is putting the drill away "nearly discharged".


It was not directed really at anyone in particular, but I was just wondering about the practical difficulties of maintaining healthy batteries in power tools. I think you have sort of answered the question though. What you would need is a battery discharger that you can plug the pack into after use that automatically drains it down to 0.9 V per cell. Otherwise I guess you would have to lock the drill in the on position and just leave it to run itself down.


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## 45/70 (Feb 8, 2010)

Mr Happy said:


> .....What you would need is a battery discharger that you can plug the pack into after use that automatically drains it down to 0.9 V per cell. Otherwise I guess you would have to lock the drill in the on position and just leave it to run itself down.



Yeah, a discharger would be nice. I think it'd be better to discharge series packs to 1.00 Volt/cell though, at least that's what I've always been told. The running the drill down method would of course work, but isn't really very practical. :sigh:

That brings us back to Li-Ion packs. They just seem like they'd be a good solution for tools that only see occasional use. Proper voltage monitoring of the pack, before and after storage, would be necessary for them to maintain good health, but I at least, wouldn't have any problem with that.

Dave


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## BentHeadTX (Feb 8, 2010)

I have found the "36 volt" Dewalt A123 Systems batteries to hold their charge for several months. 

They do COST you though!


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## UserName (Feb 8, 2010)

I have a question. What about "short-charging" a pack? I mean, where you don't wait for a charge to complete, before taking the pack off the charger and putting it to use. Does that hurt anything/reduce pack performance?


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## 45/70 (Feb 8, 2010)

UserName said:


> I have a question. What about "short-charging" a pack? I mean, where you don't wait for a charge to complete, before taking the pack off the charger and putting it to use. Does that hurt anything/reduce pack performance?



As far as I know, this doesn't have any ill effect. The only thing I can think of that might be a disadvantage, is that the cells in the pack may fall farther out of balance, if they are inclined to do so anyway, because they won't be brought to the full charge state together. In other words, this may encourage a pack to become out of balance.

Dave


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## marksun (Feb 9, 2010)

From RC car racing, generally what kills a battery pack is the death of the weakest cell. That is hastened by over-discharging the pack, like continuing to put a heavy load on the pack. When the pack dumps partially, the weak cell voltage has gone to 0v. Continued use puts a high current reverse charge on that cell if you are continuing to load the pack. Advice about not overdischarging is aimed to prevent that. Cells wired in series become imbalanced over time and after a discharge cycle may be at different stages in the individual cell discharge cycle. Equalizing the pack in this case is a good thing to protect the weak cells. If individual cell discharge is not possible, one trick is to use a resistor to drain the pack once it dumps - this causes reverse charge too, but at a lower current rate so it's not as destructive. NiCads, at least decent ones, can take an occasional discharge to zero or near zero V without damage or much damage anyway, and the benefit is derived from restarting the charge/discharge cycle with all cells at the same level. The result is longer run times and longer pack life - holds off the day you finally fry the weakest cells.


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## Databyter (Feb 9, 2010)

Turbo DV8 said:


> My cordless drill pack finally took a dump. Even from very early on, it just seemed to always be near-dead whenever I wanted to use it. I don't feel I abused it. Considering dropping $45 on a new one, but I was wondering what is the best way to use/charge a NiCd battery pack to prolong it's life. My other option is creating an 8-cell 'FrankEnloop' battery carrier and stuffing it inside and out the bottom of the old battery case. Any idea how much current a 9.6 volt drill might draw? I'm thinking I'd likely have to solder thicker gauge wires directly to the carrier contacts, instead of the thin supplied wires.


Enelopes are great, but not for this application

They are like a reliable Volvo, always there always starts, But you need a sortscar for a drill, Like Elites or something that can handle alot of current draw. You might need to charge em more often if they've been on the shelf for a few weeks, but then they will really rock and will last alot longer too under those current conditions.


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## Turbo DV8 (Feb 9, 2010)

So, it sounds like if I were to continue with NiCd, the thing _not _to do is come to use a nearly dead pack for a small job and use it until it dies, then grab the second nearly dead pack and use it while charging the first. I honestly don't think ahead and know when I will need the drill right away, but it sounds like the thing to do if I need it for a small job is to first give it at least some minimum amount of charge at least equal to the anticipated task requirement, so there is some juice in it to prevent it from reverse-charging a cell. After the job, should I then charge it all the way back up for stoarage, or leave it at a low charge level and give it another partial to full charge before the next job?


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## Mr Happy (Feb 9, 2010)

Based on what I've read, you should store it with a low charge and definitely don't charge it fully for storage. Unlike NiMH cells, it seems that NiCd cells cannot be harmed by storage in a discharged condition. I think there are stories out there of bringing NiCd cells back to good health that had been stored for maybe 20 years in a discharged state. 

On the other hand, keeping them charged does damage. When they are charged they are full of energy and that energy is just itching to go somewhere. It can amuse itself by growing large crystals, by forming whiskers, and in various other interesting ways, none of which are good for the cell.


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## cckw (Feb 9, 2010)

is this a good strategy?

periodically run the batt down in the flashlight till it starts to dim. then charge it with a wall wart for 16 hours... then repeat a time or two? What wall wart voltage vs batt voltage? 

Then say once a year run it down with the light then clip a resistor across it and run to dead-dead then slow charge. what resistor?


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## Russel (Feb 9, 2010)

cckw said:


> is this a good strategy?
> 
> periodically run the batt down in the flashlight till it starts to dim.


 
If you don't have any planned use for your cordless drill, discharge in the flashlight just intill the the light dims it is then ready for storage. I like to drop one of my batteries in it's one hour charger for about 10 minutes so that it has enough charge for a little job. (Little jobs consist of about 90% of what my cordless does.) But that isn't needed if you are willing to wait for a battery to charge when you need it. 

Then charge each battery pack and discharge for storage once a month. Assuming it isn't being used and you just want to maintain them.



cckw said:


> then charge it with a wall wart for 16 hours... then repeat a time or two? What wall wart voltage vs batt voltage?


 
I prefer to perform a forming charge once a year. Discharge the battery pack to 1 volt per cell, then charge at C/10 for 16 hours. The charge should be constant current at one tenth the capacity of the battery pack. For example, C/10 for a 2.3 amp hour battery pack is the capacity (2300mah) divided by ten (230ma.) This isn't absolutely necessary, but it would help with maintaining the battery pack. To do this properly you need a constant current charger, many hobby chargers will do. I don't think it is worth the cost to go out and buy a charger to do this just to maintain one or two cordless drill battery packs.



cckw said:


> Then say once a year run it down with the light then clip a resistor across it and run to dead-dead then slow charge. what resistor?


 
You should never discharge a battery pack with cells in series, like a cordless drill battery pack, until the pack is at 0 volts. This will reverse charge the weakest cell, damaging it.


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## Turbo DV8 (Feb 18, 2010)

Well, I found the bad cell in the pack (0.00 volts!) while all the others were between 1.25v - 1.29v. Since it's only one cell, I'm going to invest the $5 or so in a replacement and see how much time that buys me. Hereafter I will be more careful to not store the pack charged fully, and prior to use give it at least a charge up to the anticipated task. Hopefully only the one cell was sacrificial, and the others will last some time.


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## 45/70 (Feb 19, 2010)

Turbo, I've done that with NiCds when only one cell is bad, and the others appeared to be in pretty good shape. Most of the time it seemed to work out well, although the packs didn't last as long as new ones would. That's to be expected though. 

Dave


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## Turbo DV8 (Feb 19, 2010)

Question is, since I don't know the state of charge the new cell will be, should I figure a way to rig my BC-900 with jumpers and magnets to try to bring the new cell up to the other's 1.25 volts? I have no way to balance the pack, and it seems it would be better to start with cells all about the same level, than to put in a new (dead?) cell and throw the whole pack on the hour charger.


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## VidPro (Feb 20, 2010)

Quote:
Originally Posted by *45/70* 

 
_And, above all, do not run the drill past when you notice it loosing power, but do run them down frequently..._



Turbo DV8 said:


> :thinking::thinking::thinking::huh2:


 
La Difference being running it down at 30AMPS causing an extreeme reverse charge, or running it down with a lightweight discharge.
and that is how we end up with different methodology that people find works for them.
One person hears cycle them, and another person does under extreeme loads, and that aint what they were referring to nessisarily.

some slow chargers wont Wake-Up one cell in a series pack, so when driven to 0v then put on a slow charge without zapping, a person could deem that thier Ni-Cd battery was dead, because one cell hasnt been snapped out of 0v yet, and the charger doesnt snap it out.


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## SilverFox (Feb 20, 2010)

Hello Turbo DV8,

I would suggest that you use a suitable lamp to discharge each cell in the pack, including the new one you plan to install, down to roughly the same state of charge. Then you would put the pack on its charger and leave it for 24 hours.

Tom


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## Turbo DV8 (Feb 20, 2010)

SilverFox said:


> Hello Turbo DV8,
> 
> I would suggest that you use a suitable lamp to discharge each cell in the pack, including the new one you plan to install, down to roughly the same state of charge. Then you would put the pack on its charger and leave it for 24 hours.
> 
> Tom


 
I can do the lamp thing, but since the charger is a 1 hour charger, what does leaving it on for 24 hours do?


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## Russel (Feb 20, 2010)

Turbo DV8 said:


> I can do the lamp thing, but since the charger is a 1 hour charger, what does leaving it on for 24 hours do?


 
I know that with my 18v Nicad Dewalt 1 hour charger, leaving it on for an extended time allows the charger to balance the cells.

Read question 6, part 3:

http://www.dewalt.com/us/articles/article_cordless.asp?Site=cordless&ID=702


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## Turbo DV8 (Feb 25, 2010)

So I had Batteries + install the new cell. I have discharged each cell individually down to 1 volt under a 600 mA load. Now, if I don't plan on using the pack for a while, is it better to leave the pack discharged until ready to use it, or throw it on the charger for 24 hours, then let it sit until ready to use? I know the latter option is not so good, so I guess the question is, will the pack be happier sitting with all the cells discharged, or charged?


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## Russel (Feb 25, 2010)

I would charge the battery pack with it's charger for 24 hours (That will help balance the cells before you need to use it) then, if you arn't planning to use it, discharge the whole pack as a unit to one volt per cell. Then drop the battery back on the charger for only 10 minutes to give it parcial charge and you are ready for a month of storage. If you need it during that month for a short job it will be ready to go. 

If you are planning a big job, give it a full charge, but when you are done and it's ready to go back into storage, discharge to one volt per cell, charge for 10 minutes on your 1 hour charger and store your battery.


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## Turbo DV8 (Feb 26, 2010)

I put the pack on the charger, and when I walked by 30 minutes later, the indicator said the charge was already complete. It did this also before I put the new cell in. It seems 30 minutes (or less) is premature for charge to terminate on a completely discharged pack. Does this point to a problem? Does it mean other cells in the pack are weak too? Or will the subsequent charge times begin to increase now that I have taken each cell down individually?


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## Russel (Feb 27, 2010)

Let it charge over night to help balance the cells then load test it. If there are any problems with the other cells it should be apparent right away.


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## HeadlampJunkie (Feb 27, 2010)

Why can a person crack open a NiCd or NiMh drill pack and wire the packs in a series and then create an external balancing adapter to connect to one of those Lipo Balancer chargers and balance the pack every now and then?


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## Russel (Feb 27, 2010)

There is really no need, most modern 1 hour 18 volt nicad cordless tool battery chargers will balance the cells with a trickle charge when left on the charger overnight. DeWalt calls it "automatic tune up." 

It is possible to wire a balance lead so that each cell and be charged individually. Do most hobby chargers have balance lead connections for Nicad cells in a pack? Mine are wired for balancing Lipo and Lithium Ion cells, but not nicad.


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## HeadlampJunkie (Feb 27, 2010)

Russel said:


> There is really no need, most modern 1 hour 18 volt nicad cordless tool battery chargers will balance the cells with a trickle charge when left on the charger overnight. DeWalt calls it "automatic tune up."
> 
> It is possible to wire a balance lead so that each cell and be charged individually. Do most hobby chargers have balance lead connections for Nicad cells in a pack? Mine are wired for balancing Lipo and Lithium Ion cells, but not nicad.


 
I want to verify that these chargers that come with tool packs are really balancing the cells and the only way to do that is hooking the packs to a Lipo balancer/charger system. 

From what I've read all you have to do is wire the pack to accept a balancing plug to the Nicad and or NiMh packs and the Lipo balancer/charger will do the rest.


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## Russel (Feb 27, 2010)

I don't see the need with Nicad Battery packs. Lithium tool battery packs incorporate actual balance leads because they need them due to the chemistry.

Nicads tolerate overcharging with a low current very well and this can be used to balance the cells. Lithium based batterys would not respond well to that, thus actual balance leads for each cell.

Take a look at the inside of a DeWalt 36 volt Lithium Nano Phosphate battery pack:

http://www.rcgroups.com/forums/showthread.php?t=587606&highlight=dewalt+36v


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## Turbo DV8 (Feb 28, 2010)

Russel said:


> Let it charge over night to help balance the cells then load test it. If there are any problems with the other cells it should be apparent right away.


 
I did let it continue to charge for 24 hours. I used the drill a few minutes today under light load, and it seemd to spin up fine. It's funny... when the LED quit flashing ("charged") the top of the pack was not really noticeably warm. Trickling overnight, the next morning it was quite noticeably warm, but not hot. Is it normal for the pack to continue to heat up even on trickle?

Yesterday I drained each cell down individually on my other good battery pack, then put it on charge. 25 minutes later it also indicated it was "charged." I am thinking the sub-30 minute charge time is normal for this "one hour" charger. Here are the numbers; what do you think? The guy at Batteries + said the replacement NiCd 3/5 C cell was 1200 or 1300 mAh, so I assume that's about what the pack is. The pack is 9.6 volts. The DeWalt charger says, "9.6V - 14.4V. One Hour charger. Output: 2.8 amps." So, if the pack is 1200-1300 mAh and the charger puts out 2.8 amps, besides being a helluva major charge rate, that would make 25 minutes about the expected charge time? Jeez, that's over 2.0C charge rate. Between that and duffus's like I use the drills sometimes 'till they won't turn anymore, and I wonder how I was so lucky to have only one cell in the pack croak!


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## Russel (Feb 28, 2010)

Turbo DV8 said:


> ... Trickling overnight, the next morning it was quite noticeably warm, but not hot. Is it normal for the pack to continue to heat up even on trickle? ...


 
Yes, it is normal for the battery to get a little warm after trickle charging overnight. Basically, the charger is overcharging the cells causing the lower cells to fully charge even if the stronger cells are already full. That will cause the battery pack to get warm. You only need an overnight balance charge once in a while to help keep the cells even. 

It is possible that your charger is charging the battery at 2C, I don't know how the charger is designed to accommodate different voltage batterys. Nicad cells can handle higher charge rates fairly well so I wouldn't be too concerned. What model charger is it?


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## SilverFox (Feb 28, 2010)

Hello Turbo DV8,

2C is an acceptable charging rate for NiCd cells. It would be interesting to know what the trickle charge rate is...

Tom


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## Turbo DV8 (Mar 1, 2010)

Russel said:


> You only need an overnight balance charge once in a while to help keep the cells even ... What model charger is it?


 
DeWalt model # DW9107. The S/N does not fall within the range of those recalled. Does this trickle/balancing charge apply to other or all cordless drill chargers? I also have an 18V Ryobi, charger model #1423701. If this trickle/balancing is known to work on that, I'd like to do it before I toast one of those packs. 

When I got that drill a couple years ago, Ryobi was selling twin-packs of the 18V batteries for $25 at Home Depot. Not a sale price, every day price. Now I go look and see the twin-packs are no longer available, and the price of a single pack is around $40-$45! I know that's about normal for the DeWalt's and others, but if Ryobi could sell two for $25 two years ago, why the huge jump in cost? Only because they can get that much for them because it is equivalent to other pack prices?


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## SubLGT (Aug 20, 2014)

I recently came across these 2 PDF documents that have helpful info about maintaining NiCd and NiMH battery packs:

http://www.camlight.com/techinfo/camlight_techtips.pdf

http://www.camlight.com/techinfo/camlight_whydischarge.pdf


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