# 18650's Care and Maintenance



## acbezzi

hello,
i´ve just bouhgt my first 18650 light (fenix TK12 R5), batteries (Trustfire protected) and charger (WF 139). 
i have many doubts on the use (charging ,discharging, storing) of this type of battery. i´ve searched in the forum some topic on it but i couldn't find any. i´d appreciate if u guys could help me.:thumbsup:

my doubts are; 

how should i store my 18650's, charged or discharged?
do they have memory effect? i mean, should i completely discharge them before charging again?
how long can they keep their energy without being used? i mean, would they be ready for use if i store them charged? or i should charge them just before use?
are there any safety reccomendations for charging them, besides not leaving them alone?
do they get too hot while charging? should i place a fan or cooler in front of them while charging?
are there any hints to prolong their life?
my light (fenix tk12) can use either two cr123a or one 18650. what do u think would be the advantages and disadvantages of both?
thax 4 the help


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## Illum

acbezzi said:


> how should i store my 18650's, charged or discharged?
> do they have memory effect? i mean, should i completely discharge them before charging again?
> how long can they keep their energy without being used? i mean, would they be ready for use if i store them charged? or i should charge them just before use?
> are there any safety reccomendations for charging them, besides not leaving them alone?
> do they get too hot while charging? should i place a fan or cooler in front of them while charging?
> are there any hints to prolong their life?
> my light (fenix tk12) can use either two cr123a or one 18650. what do u think would be the advantages and disadvantages of both?
> thax 4 the help



first off, heres some reading to do: Rechargeable Lithium Battery Information - Protected vs. Unprotected Li-Ion Batteries 
Read through the basics of Mdocod's MDs Lithium-Ion > Incandescent guide + compatability/comparison chart thread

Enough reading, look at these pictures
Vidpro's "illustrated battery charging concept"
https://www.candlepowerforums.com/threads/235745

Vidpro did a good job explaining why cells heat up here, as well as illustrations beginning in post 4
https://www.candlepowerforums.com/threads/270416

If you like to see the technical stuff, consult NewBie's Li-Ion protection technology and possible dangers thread 

There are battery experts aboard the forum, but I'll just share what I know

btw, :welcome:

It is preferred to have the cells charged for storage. Never attempt to completely discharge cells [~3.8V under load]
I've stored my 17670s for a month without significant drop in charge, but then again I'm storing them in a place where its 77F all year and out of the sun. With basic common sense storage practices you should be fine. I bought rechargeables to eliminate my use of CR123As for nightly excursions, so usually my cells are cycled over and over, barely left in storage for half a month. 

Since there are many different types of chargers available, I recommend you to read through Mdocod's Consumer Li-Ion "cradle" charger roundup thread to get a better handle on what charger to buy as well as the characteristics of your charger. 

Like all batteries, once its capacity is saturated it will begin to convert the additional energy into heat. If your batteries [I'm assuming unprotected] are heating up during charging. It is likely to originate from two possibilities:
the first is your charger is unable to terminate charge accurately. The other is that the charger only has a single channel, but you are charging two cells in parallel and the cells have a different state of charge between each other. This causes one cell to be overcharged and the other undercharged. 

I would prefer to have protected cells in my collection because they protect from overcharge and overdischarge by disconnecting the battery 

Note that due to internal resistance any battery chemistry will heat up slightly during charge [as well as discharge], this is normal. It should be warm to the touch and not "hot"

Prolonging their life requires some understanding of battery conditioning, and honestly I'm not doing a good job on mine:shrug:

its debatable on advantages and disadvantages of rechargeables because it involves a couple variables to which you as a user can apply.
If the driver of your light is capable of either, the 18650 is a batter choice, but keep in mind that 2xCR123A has a overall dimension of twice the length of a cr123A, ANSI dimensions as "16340" or 16mm wide, 34mm long, cylindrical. 2xCR123A is then comparable in width to a 16mm wide and approx 68mm long cell. Its closest alternative is actually the 17670 cell. 18650 is the same length but 2mm wider, so normally on lights designed for cr123as 18650s would not fit. 

if you use your light only sporadically, rechargeables are not a good investment, especially considering the additional costs of charger and stress .
However, if you use your flashlight every night, rechargeables are the better option because it saves the cost of replacement cells.

There an abundant amount of information on the forum for Li-ions simply because there are so many users here who uses them


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## LuxLoverr

great topic! thanks to both


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## march.brown

Illum said:


> if you use your light only sporadically, rechargeables are not a good investment, especially considering the additional costs of charger and stress.


I would agree with this when using (for example) AA and AAA cells ... My iTP A2s and A3s are used a lot so I always use Eneloops or Hybrios in them ... I also use a few Lithium Primaries AA & AAA (plus spares) in a couple of other torches kept only for emergencies , like in the car.

Unfortunately there is no really compact primary cell to replace my 18650s , so I have to use the Li-Ion rechargeables ... I don't use the three torches (with 18650s) for long periods and I don't recharge them very often ... I probably charge a 18650 every three weeks or so and sometimes even this is before they are fully discharged ... I like the 18650s because I can leave them for months and (if unused) they still measure almost 4.2 volts ... I only check the voltage every three weeks or so ... I realise that it is better to store Li-Ions only partly charged , but I ignore this and keep them fully charged ... My Li-Ions will die of old age rather than due to charging too many times , but I will just replace them every three or four years ... I use Ultrafires so it isn't expensive to replace them.

If anyone is considering using Li-Ion cells , I would suggest that a Digital Voltmeter is bought as this is the only way to tell how much charge is left in the battery ... There are several good threads on CPF about charging and care of Li-Ions and it is essential to read these carefully before embarking on using the Li-Ion cell.

As for the 123 size battery , I would stick to primaries where possible and (preferably) single cell torches ... There again , that is only *my* opinion.
.


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## acbezzi

thank u a lot illum!!!:thumbsup: your post was really helpfull!! my light can hold up two cr123a or one 18650. i have already bought some batteries( two TrustFire Protected 18650 3.7V 2400mAh and two TrustFire Primary CR123A) and a charger (Ultrafire WF139). i´m thinking about using primarily the rechargeable 18650 and leaving the cr123a's in my bag as emergency batteries. comparing one 18650 with two cr123a, which do u think would give more power(light) / runtime?


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## acbezzi

thank u mark brawn!


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## Illum

march.brown, there is some logic to storing cells at a partially charged state...and I think either mdocod or LuxLuthor gave a percentage of the state of charge for long term storage. 
You are hopping along in the right direction. Until I can find that value in a post I'm holding off lest to lead anyone in the wrong direction

DM51 once noted in this thread https://www.candlepowerforums.com/threads/274781


DM51 said:


> Best storage for Li-Ion cells:
> · 3.9V
> · Between 3°C-10°C
> · Dry conditions.
> 
> Never store Li-Ion cells:
> · Below 3.6V or above 4.1V
> · Below 0°C or above 30°C
> · Humid or wet atmosphere



*EDIT*: I forgot to mention this great website called battery university, its an added reference to what we on the forum may have missed during our time explaining 
How to prolong lithium-based batteries

yep, apparently the magic number is 40


> If possible, store the battery in a cool place at about a 40% state-of-charge. Some reserve charge is needed to keep the battery and its protection circuit operational during prolonged storage. Avoid keeping the battery at full charge and high temperature. This is the case when placing a cell phone or spare battery in a hot car.





acbezzi, thats where certain members of the forum shines, user Selfbuilt reviewed the TK12 sometime in May and posted a review on it. Like many of his earlier [and later] contributions, it will just about answer all the questions the ower would want to know about the light: output, runtime, ergonomics, etc :twothumbs

to answer your question, referring to Selfbuilt's graphs under the assumption that your TK12 was the same as his
AW protected 18650:
Max 2hr 15min to 50% output
High 7hr 18min to 50% output
Medium 15hr 27min to 50% output

2xCR123A
Max 1hr 54min to 50% output
High 5hr 49min to 50% output

Interestingly as it seems the onboard regulator is designed for 18650s, and the 2xCR123A option is added to which the driver overhead allows.

Its always a good idea to keep some CR123As on you, on occasion I would find the need to use my cr123as in lights I brought without spares. In case you're wondering how to go about carrying cells, I'd recommend doing a little hunting around and be a little creative 
Battery Holders --Also "Utility Bag" suggestions
How to carry batteries with you
CR123A carriers?
How do you carry spare batteries

Personally I found it easier just to carry another light, chances are where you'll need a light you wouldn't be able to see your own hands in front of your face, thats not the best time to lose a tailcap or load cells backwards. I still own carriers though, mostly for bail-out bags and field provisions. While a little expensive, surefires SC1, SC2, SC3 are good battery carriers, very sturdy little guys that holds 4-6cells in pairs, even comes with a o-ring where the threads meet. Only issue for the SC1 is once awhile theres the risk that there will be a crazy TSA agent/border patrol/military nut living next door thinking you're carrying a VS50...which in design it does resemble the VS50, or a plastic shelled anti-personnel mine. So my SC1 mostly stays at home 


Cheers


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## march.brown

Illum said:


> march.brown, there is some logic to storing cells at a partially charged state...and I think either mdocod or LuxLuthor gave a percentage of the state of charge for long term storage.
> You are hopping along in the right direction. Until I can find that value in a post I'm holding off lest to lead anyone in the wrong direction


 Hi Illum , I realise that storing Li-Ions in a partially charged condition will give them a longer life , but I'm not worried about gaining a few extra months of cell-life ... I prefer to have all my batteries in a ready-to-use state rather than have to put them on charge before using them ... Personal preference really ... All my LSD AA and AAA cells plus my 18650s are ready to use , even though I don't change them very often.

I check the voltages of the spare Li-Ions every few weeks and today they are either 4.15 or 4.16 volts ... There is one at 4.11 and another at 3.83 but they haven't been charged for quite a few months ... Those two are Ultrafire unprotected (blue) and all the others are Ultrafire protected (grey) ... I don't buy expensive Li-Ions as I will just simply buy more cheapies when these eventually die ... As I said before , this is personal preference and I'm happy with my cell choices so far ... Time will tell.

I also use cheapie protected 18500 Li-Ions in my converted Maglite 2C. 

In the 123 size torches , I only use primary cells.
.


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## Black Rose

Illum said:


> if you use your light only sporadically, rechargeables are not a good investment, especially considering the additional costs of charger and stress .


When I got my Li-Ion cells I thought that I would get a lot of use out of them, but it turns out that is not the case.

I am now at a point where I wonder if I should have even invested in the Li-Ion cells. 
I already sold off my 16340 cells as they were not getting any use.
My 17670 cells get no use because the drivers in the drop-ins in my 6P and G2L won't stay in regulation with a single Li-Ion cell, so those lights now have 2xCR123A primary cells in them.

I like having my lights loaded and ready to go, but I have many lights and it seems that I end up using my AA and AAA lights more than my larger lights most of the time.

With hindsight being 20/20, what I probably should have done was buy a pair of 18650 cells and put the cells in the light that I want to use _at the time I want to use it_, instead of having a cell for each of the lights.

With low voltage drop-ins, better boost circuits, and low vF emitters now available, _my_ need for Li-Ion cells seems to be slowly going away.


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## march.brown

Black Rose said:


> With hindsight being 20/20, what I probably should have done was buy a pair of 18650 cells and put the cells in the light that I want to use _at the time I want to use it_, instead of having a cell for each of the lights.


I keep my spare 18650s in torches rather than in plastic boxes ... The torches can even be used if necessary.

My main 18650 torches are Solarforce L2's and L2i's , so I can use any one of them ... Unfortunately , I still have some 18650s in plastic storage boxes , though I have just sent for another L2i for $12-56 including postage ... I realise that this is more expensive than a plastic storage box , but it looks better.
.


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## mdocod

Hi Illum,

Keep in mind that the 3V rating on a CR123 cell is different from the 3.7V rating of a li-ion cell. The trend in the industry tends to be that rechargeable cell voltage ratings are closer to their nominal loaded average voltage, while primary cells are often rated closer to their open circuit voltage. In other words.... Getting 4.2WH (8.4WH for a pair) from a CR123 is pretty rare, but getting 9+WH from an 18650 is quite possible. 

Eric


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## etc

that's a good point, I hear CR123A is more like 2.8V under load?


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## qandeel

Good topic.

Thanks to all the contributers. We keep learning everyday.


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## Monocrom

qandeel said:


> Good topic.


 
+1

Deserves to be a sticky.


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## Illum

Black Rose said:


> When I got my Li-Ion cells I thought that I would get a lot of use out of them, but it turns out that is not the case.



I know the feeling, but I started out exploring then just stuck to running 17670s in Surefires, not so much for the regulation but for the benefit of whipping out a light that shined as if used with new cells week after week. Gradually I sold/given away the LiCoO2s I didn't use [10440s, 14500s, 18500s] and stuck with cycling two 17670s in Surefire L4s. Several years after I bought my protected 17670 it will still hold a charge, but the runtime is very poor...so I decided to retire them. One of which I have removed the protection PCB, soldered some wires to it, and now became a charging dock for unprotected cells

Its not pretty, but in a single channel DSD featuring a lousy termination point some added protection is always welcome








mdocod said:


> Hi Illum,
> 
> Keep in mind that the 3V rating on a CR123 cell is different from the 3.7V rating of a li-ion cell. The trend in the industry tends to be that rechargeable cell voltage ratings are closer to their nominal loaded average voltage, while primary cells are often rated closer to their open circuit voltage. In other words.... Getting 4.2WH (8.4WH for a pair) from a CR123 is pretty rare, but getting 9+WH from an 18650 is quite possible.
> 
> Eric




 let me go and edit that



Monocrom said:


> +1
> 
> Deserves to be a sticky.



Anything Mdocod sets his foot in has that feeling


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## mdocod

etc said:


> that's a good point, I hear CR123A is more like 2.8V under load?



Can be as low as 1.8V under a load if you are SureFire many years ago making a "special" bulb for an M4 that only runs a few minutes 

Typically, voltage can vary from ~2.2-2.8V on average depending on the load. A 1C discharge rate (1 hour tun) will result in an average voltage ~2.5V through the discharge. 

------

Rule of thumb is that li-ion will pull ahead of CR123s under more intense loads, while CR123s will have more energy available when discharged very slowly. 


Eric


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## Mikellen

I also just started using rechargeable batteries specifically an 18650 protected battery from AW. I do have a volt meter and check the voltage regularly but can someone please let me know at what voltage should I not let the battery drop down to before charging?

Thanks.


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## Illum

Aw protected cells only protect against severe overdischarge and usually will not kick in even when cells have already entered into a deep cycled state. Its designed to kick in to prevent a fire or an otherwise hazardous situation, its not meant for the normal operation ofcells. Likewise so are overcharge protection, only some of the nutcases here [like me] depends on it for normal operation. My take for whats "need recharging" is about 3.9V...

I'm not sure where this came from but I have it taped beside my charger and have been using it for years to manually estimate remaining cell capacity. The capacity of cells to voltage is stated as follows:



Code:


Capacity   OCV    Load = 550ma
100%      4.20V    4.20V
90%       4.06V    3.97V
80%       3.98V    3.87V
70%       3.92V    3.79V
60%       3.87V    3.73V
50%       3.82V    3.68V
40%       3.79V    3.65V
30%       3.77V    3.62V
20%       3.74V    3.58V
10%       3.68V    3.51V
5%        3.45V    3.42V
0%        3.00V    3.00V

This chart is only meant for rough estimation only, as DM51's numbers will quickly become apparent following this thread *li-ion discharge limit - 2.5v/2.7v/2.8v/3v???*


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## pae77

Mikellen said:


> I also just started using rechargeable batteries specifically an 18650 protected battery from AW. I do have a volt meter and check the voltage regularly but can someone please let me know at what voltage should I not let the battery drop down to before charging?
> 
> Thanks.


Most people seem to say ~3.8 volts is a good point at which to recharge Li-ion cells. At 3.8 volts there is approximately 30-40% remaining power in the cell so that gives you some margin of safety. There is no harm in topping up Li-ion batteries that are partially discharged but there is harm in discharging them too low. I would try to avoid ever discharging them below 3.6 volts at which point they are effectively empty.


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## Mikellen

Thanks for the information. It is extremely important to know!


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## pobox1475

I have been using AW protected cells (18650, 17670, 14500 & RCR123's) for over a year now. I usually top them off frequently. After recently acquiring a ZL H30 during use on high the protection circuit kicked in on a 123. Is this cell now compromised? Will it still perform like it did before this event after being recharged? I use a Pila IBC for charging duties.


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## Illum

pobox1475 said:


> I have been using AW protected cells (18650, 17670, 14500 & RCR123's) for over a year now. I usually top them off frequently. After recently acquiring a ZL H30 during use on high the protection circuit kicked in on a 123. Is this cell now compromised? Will it still perform like it did before this event after being recharged? I use a Pila IBC for charging duties.



By protection kicked in meaning the light was working normally and it just shut off? If so it just means the cell is depleted or shorted somewhere along the way. AW RCR123As according to a couple third party tests appear to be less than ideal for heavy loads and only guarantees a percentive of the "750mah" capacity at moderate loads. How old is your AW cell? as cells age due to cycling it becomes easy for cells to drop in voltage under load than compared to a new cell. I think this is why on laptops as the battery gets old the meter may indicate 100% but when you try and use it it'll run for ~2 minutes then the computer will go out when a new cell pack could last several hours


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## pobox1475

Cell was almost new. First time I had one go all the way down. Unfortunately my meters are out of state in storage. I put it on charger and it seemed to charge and terminate normally. Had the ZL on high for about an hour and then it just abruptly went off. In normal uses is it very bad to have the circuit kick in?


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## Illum

pobox1475 said:


> Cell was almost new. First time I had one go all the way down. Unfortunately my meters are out of state in storage. I put it on charger and it seemed to charge and terminate normally. Had the ZL on high for about an hour and then it just abruptly went off. In normal uses is it very bad to have the circuit kick in?



I wouldn't know because it never happened to me more than once or twice through a couple of years
An hour on high sounds a bit rough though


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## pobox1475

> An hour on high sounds a bit rough though


 Yea. Did not know how long I would have on high. Per their specs primaries yield 2.5 hours. I was close to shutting it down for a cell swap when it ended.


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## sidecross

I am new to Eagletac 18650 3100 mAh Li-ion batteries and this topic or thread has anwered my questions.

I thank everyone and this web site for this richh source of information. :thumbsup:


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## 777qqq

What is the best open circuit voltage to store 14500 and 10440 Li-Mn and 18650 Li-Ion batteries at? Do they need to be cycled if used for regular consumer use? Thanks.


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## bwDraco

Wow, that was a big necropost. The last post was 2-1/2 years ago.

Don't deep-cycle Li-ion batteries, this will shorten their life. Li-ion does not develop memory the way NiCd does.

For modern high-capacity lithium-cobalt cells such as the Panasonic NCR18650B, the optimal open-circult voltage is about 3.6-3.7 V, which represents an approximately 35-45% state of charge. Avoid discharging batteries to below 2.75 V under load or 3.2 V open-circuit, as this will shorten their life as well. Discharging to less than 2.5 V open-circuit will damage the battery and compromise safety, and attempting to recharge a battery at an extremely low voltage (less than 2.0 V) can result in a fire. I would personally try to avoid discharging below 3.5-3.6 V open-circuit whenever possible for optimal service life.

Today's Li-ion batteries are designed to operate to slightly lower voltages, which expains the lower voltages I'm giving. Cells using older technology generally should not be discharged below 3.0 V under load or 3.6 V open-circuit.

—DragonLord


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## 777qqq

So I should store my 14500 and 10440 Li-Mn and 18650 Li-Ion batteries at 3.6-3.7 V open-circuit? How long will they remain at 3.6-3.7 V before I need to charge them back up to 3.6-3.7? I accidentally posted in this thread instead of creating a new thread.


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## more_vampires

Also, don't forget "cool, dry place" if you're going to this depth.


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## Keeper Oath

My first 18650 flashlight (TN30) will be here by Saturday. I have no familiarity to the battery so this thread is valuable to me. As much as these little jewels cost, I want to maintain them with a lot of TLC.


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## QuantumSam

Just ordered my first 18650 flashlight - Sunwayman C22C - what battery brands are good? What should I avoid? 

Should I use 3000 mAh and higher? Or are 2500 mAh good enough capacity?


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## Ubec

This topic is *extremely* helpful for newcomers like me.

Thanks to those users who shared their knowledge!


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## Lumencrazy

777qqq said:


> So I should store my 14500 and 10440 Li-Mn and 18650 Li-Ion batteries at 3.6-3.7 V open-circuit? How long will they remain at 3.6-3.7 V before I need to charge them back up to 3.6-3.7? I accidentally posted in this thread instead of creating a new thread.



I have had Panasonic NVR18650B (unprotected) stored at 3.4 volts in a fridge for over 5 months with no drop in voltage. The lower voltage and temperature lowers the chemical potential of the system, thereby, slowing down any unwanted reactions


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## LAMPARITA

I have a Olight 18650 and the protection plate on the back-end of the battery got loose while trying to pull the battery out of the flashlight. Plate still attached to the battery bottom but I'm just wondering if it's safe or not to use it the way it is?


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## kj2

LAMPARITA said:


> I have a Olight 18650 and the protection plate on the back-end of the battery got loose while trying to pull the battery out of the flashlight. Plate still attached to the battery bottom but I'm just wondering if it's safe or not to use it the way it is?



So the plastic wrapping isn't holding/surrounding the metal plate? In that case, you could shrink wrap a new plastic tube around it. Remove the existing wrap before adding the new one.


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## LAMPARITA

Correct, plastic wrapping isn't holding the plate so I will try to do the re-wrapping when I get home tomorrow evening but in the meantime, I will like to know if the battery can still be use the way it is? Just asking for safety reasons.

Thank you for responding



kj2 said:


> So the plastic wrapping isn't holding/surrounding the metal plate? In that case, you could shrink wrap a new plastic tube around it. Remove the existing wrap before adding the new one.


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## kj2

LAMPARITA said:


> Correct, plastic wrapping isn't holding the plate so I will try to do the re-wrapping when I get home tomorrow evening but in the meantime, I will like to know if the battery can still be use the way it is? Just asking for safety reasons.
> 
> Thank you for responding



I wouldn't take the risk.


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## vadimax

I am lost with those safety levels. Real situation right now: I have bought a Xtar 18650 3400mAh, poked it into a Thrunite TN12 (2016), and used it for some time till I came home where I do have a charger. When I put the battery to charge I was a bit scared -- Thrunite MCC-4 showed 1.5V. Having read all these horror stories about over discharged Li-Ion I was ready to run and get cover, but Xtar safely and calmly reached 3.7V without any sign of becoming any warmer than the room temperature. After that I reinserted it and now it is going after 4.2V. And only now the battery and the charger are becoming slightly warmer.

What am I doing wrong?


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## gigbyt

Thanks for all this useful info, one can read for hours here at this forum.


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## vadimax

One thing that I consider impractical with Xtar's 18650: protective PCB at its bottom has a copper surface. I dare to guess it is not too thick. Taking into consideration that protected batteries are generally longer than unprotected, the flashlight springs apply more pressure to the battery. As a result, if you have not a chargeable light, you have to screw/unscrew it roughly 500 times. The springs are made of steel... against copper... The Xtar 18650 has a chance to fail long before it will deteriorate chemically.

P.S.: Are you kidding? My post is too short?!


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## gbye darkness

vadimax said:


> I am lost with those safety levels. Real situation right now: I have bought a Xtar 18650 3400mAh, poked it into a Thrunite TN12 (2016), and used it for some time till I came home where I do have a charger. When I put the battery to charge I was a bit scared -- Thrunite MCC-4 showed 1.5V. Having read all these horror stories about over discharged Li-Ion I was ready to run and get cover, but Xtar safely and calmly reached 3.7V without any sign of becoming any warmer than the room temperature. After that I reinserted it and now it is going after 4.2V. And only now the battery and the charger are becoming slightly warmer.
> 
> What am I doing wrong?



Same here, Vadimax! I bought a lamp from a seller in E-Bay UK, which came with three UltraFire 3600 mAh-cells. Re/Discharging protection circuit.

But when the lamp ran out of juice and became dim, I inspected batteries. All were between 1,42 - 1,46 Volts!!! Scary! However, I decidec to charge them with my Nitecore-charger. It seemed to work well, they did not got hot and only slightly warm. I measured 4.21-4.22 Volts from them.

Are these fake batteries without a protection circuit or how is this possible as they discharged so low to 1,45 Volts? Can I still use these or throw them into bin?


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## vadimax

I guess, in my case a battery was stored for too long. It is kind of expensive for Lithuania, so no one is buying them. Perhaps, natural discharge. After being charged to 4.2V, it behaves normal so far.


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## HKJ

vadimax said:


> Thrunite MCC-4 showed 1.5V.



This probably means the safety of your cell is lowered, i.e. the risk of it bursting into flame is higher.
This does not mean it will exploded, but your safety factor is lower.


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## Monocrom

gbye darkness said:


> Same here, Vadimax! I bought a lamp from a seller in E-Bay UK, which came with three UltraFire 3600 mAh-cells. Re/Discharging protection circuit.
> 
> But when the lamp ran out of juice and became dim, I inspected batteries. All were between 1,42 - 1,46 Volts!!! Scary! However, I decidec to charge them with my Nitecore-charger. It seemed to work well, they did not got hot and only slightly warm. I measured 4.21-4.22 Volts from them.
> 
> Are these fake batteries without a protection circuit or how is this possible as they discharged so low to 1,45 Volts? Can I still use these or throw them into bin?




:welcome:

With regards to Ultrafire, it's well-known among the flashaholic community that all Ultrafire cells are nothing more than generic ones recovered from used laptop computers. No such thing as a fake Ultrafire cell because the downright cheapest Made in China flashlight company with a brand name, doesn't actually make their own cells. Generic, recovered batteries with an "Ultrafire" label slapped on each one. It's why the company can afford to undercut the few competitors it has. Namely the ones that actually produce their own batteries. 

Some "Ultrafire" cells work, some work after only one charge, some can't hold a charge at all, and some simply won't charge up (again, at all). It's pot-luck what you'll get. Anything from barely decent to non-working junk. Don't worry. You're not the first to get tricked by Ultrafire. I did, when first starting out in this hobby. And, you won't be the last. 

Get some quality AW brand rechargeable cells.


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## gbye darkness

Monocrom said:


> :welcome:
> 
> With regards to Ultrafire, it's well-known among the flashaholic community that all Ultrafire cells are nothing more than generic ones recovered from used laptop computers. No such thing as a fake Ultrafire cell because the downright cheapest Made in China flashlight company with a brand name, doesn't actually make their own cells. Generic, recovered batteries with an "Ultrafire" label slapped on each one. It's why the company can afford to undercut the few competitors it has. Namely the ones that actually produce their own batteries.
> 
> Some "Ultrafire" cells work, some work after only one charge, some can't hold a charge at all, and some simply won't charge up (again, at all). It's pot-luck what you'll get. Anything from barely decent to non-working junk. Don't worry. You're not the first to get tricked by iUltrafire. I did, when first starting out in this hobby. And, you won't be the last.
> 
> Get some quality AW brand rechargeable cells.



Thanks, mate! I ordered 8 Sanyo cells and earlier had ordered 4 SkyRay protected cells. Dont know about the SkyRays, if they are any good? I have a four-cell SkyRay lamp as well.

I've had a couple of single-cell 18650 lamps for years, no problems. But with these multi-cell lamps, better be safe than sorry. Meanwhile I will be monitoring those Ultrafures vigorously...


----------



## MarioJP

This is a good thread. I recently made the jump and got my first 4 NCR18650B's. While i did ran into some issues (not the cells themselves). I manage to work around it. My question is.. As these cells begins to wear out as time goes by and repeated use. Is there anything i should be aware as these cells age. like reduce charging current,etc?. I am using these cells in my power bank which takes 4 18650's. That is a lot of capacity thus making it a huge upgrade compared to what i was using before lol.

Thanks.


----------



## CelticCross74

wow! Even now in 2016 countless people are still being fooled into buying utrafire cells! I freely admit that years ago a pair of my first cells were 3600mah Ultrafires with the red wrapping and slick black and grey design at one end. I was a total noob. I could never figure out why these cells constantly needed to be recharged. At the same time I had a couple 2900mah Fenix cells that out ran the expensive ultrafires by 10 to 1. It wasnt until I discovered CPF that I learned that my mighty ultrafires were at best 600mah re wrapped cells yanked from junk yard laptops. Ever since I take my cells very seriously. I only buy from a couple of legit sources now only and they have never steered me wrong.

As for building a battery pack flat top high mah Pannies, Samsung and LG's are what I understand are what are made into battery packs for anything from laptops to the huge power banks for Teslas and Toyota Prius'.

From what I understand the whole reason 3600mah cells sold out so quickly is that they were bought en masse by laptop makers and Tesla. Correct me if I am wrong but Olight stands alone with their new proprietary 3200 and 3600mah cells with next gen protection circuits built into the positive end only they are advanced to the point where no circuit is needed on the negative end nor is a conductive strip needed to connect the two ends anymore. Olight does not make flat top versions of these cells thus they are the only ones like it on the market and were designed for flashlight use only.

They are expensive but Im gonna buy some of these super circuit 3600mah Olights.

Ill end with this...all of the above information was told to me by Sal at Orbtronic. Sal also said Panasonic was supposed to drop a 4000mah cell in 2015 but where just to overwhelmed with demand for all their other flat top cells by the laptop industry and specifically Tesla. The 4000mah tooling and assembly lines are there and ready to be fired up. I expect these new super cells to drop 2nd quarter of 2016. Big question is will they fit lights? Rumor has it that its Tesla pushing for bleeding edge tech 18650's so we will have to wait and see...


----------



## tfh

Is combining 18650's of different (top-quality) manufacturers in one light a problem? And if so why? 
(I understand why e.g. Fenix does not recommend, but is there a real reason?)


----------



## ven

Yes, stick with same brand in each multi cell light to keep things on an even keel. No mixing of age/brand and mah simply put...........Buy the amount of cells for the light in one go from the same batch(hopefully). By mixing cells, amount of cycles they have been through and various ages will mean there will be weaker cell/s in the mix. The risk of running a cell/s down more than the other/s becomes an issue and you can have problems............or worse.

Most manufacturers only recommend their own cells, there is no need for this generally(unless a specific type). Most big name manufacturers use the same panasonic etc etc inside, adding their PCB/label on the outside. Still not to mix say a nitecore 3400 with a fenix 3400 due to different ages and states of use being from different batches.

Sure more can be added, bottom line dont mix cells

:welcome:


----------



## djdawg

What the voltage of two 18650 ..........is it more than 9 volts ?
LOL.....I know nothin
I have a Malkoff M-61 drop in that I want to use in a two 18650 batt body ...........can I ??


----------



## Mchipman

Just ordered an Olight S2 and this topic has been great. Thanks for all the great info.


----------



## ven

djdawg said:


> What the voltage of two 18650 ..........is it more than 9 volts ?
> LOL.....I know nothin
> I have a Malkoff M-61 drop in that I want to use in a two 18650 batt body ...........can I ??





2x 18650 cells are 4.2+4.2=8.4v so the drop in will need to support that voltage. So it is less than the 9v, if that is what that drop in is rated for=good to go!


----------



## stephenk

CelticCross74 said:


> wow! Even now in 2016 countless people are still being fooled into buying utrafire cells! I freely admit that years ago a pair of my first cells were 3600mah Ultrafires with the red wrapping and slick black and grey design at one end. I was a total noob. I could never figure out why these cells constantly needed to be recharged. At the same time I had a couple 2900mah Fenix cells that out ran the expensive ultrafires by 10 to 1. It wasnt until I discovered CPF that I learned that my mighty ultrafires were at best 600mah re wrapped cells yanked from junk yard laptops. Ever since I take my cells very seriously. I only buy from a couple of legit sources now only and they have never steered me wrong.
> 
> As for building a battery pack flat top high mah Pannies, Samsung and LG's are what I understand are what are made into battery packs for anything from laptops to the huge power banks for Teslas and Toyota Prius'.
> 
> From what I understand the whole reason 3600mah cells sold out so quickly is that they were bought en masse by laptop makers and Tesla. Correct me if I am wrong but Olight stands alone with their new proprietary 3200 and 3600mah cells with next gen protection circuits built into the positive end only they are advanced to the point where no circuit is needed on the negative end nor is a conductive strip needed to connect the two ends anymore. Olight does not make flat top versions of these cells thus they are the only ones like it on the market and were designed for flashlight use only.
> 
> They are expensive but Im gonna buy some of these super circuit 3600mah Olights.
> 
> Ill end with this...all of the above information was told to me by Sal at Orbtronic. Sal also said Panasonic was supposed to drop a 4000mah cell in 2015 but where just to overwhelmed with demand for all their other flat top cells by the laptop industry and specifically Tesla. The 4000mah tooling and assembly lines are there and ready to be fired up. I expect these new super cells to drop 2nd quarter of 2016. Big question is will they fit lights? Rumor has it that its Tesla pushing for bleeding edge tech 18650's so we will have to wait and see...


The 3600mAh Olight 18650s are actually wrapped 3500mAh Sanyo 18650GAs with a relatively restrictive protection circuit. There are better protected GAs available from Orbtronic, Keeppower, or Blazar.


----------



## Dr. Manhattan

I'm thinking of buying a flashlight which uses 18650, but I'm unsure how to store the batteries inside my house without risking everything burning down.

What happens if I fully charge a 18650 to 4.2V and then just place it in a box for two years? Will the battery just be useless/destroyed or could it start vent/burn due to the self-discharge?


----------



## Lexel

That fully charged battery will have 3.9V, lost maybe 20% of its capacity
there is no danger for venting or catching fire

batteries catching fire is mostly caused by overdischarge(and charging it again nstead of recycling it), mechanical damage or overcharge


----------



## Dr. Manhattan

Lexel said:


> That fully charged battery will have 3.9V, lost maybe 20% of its capacity
> there is no danger for venting or catching fire
> 
> batteries catching fire is mostly caused by overdischarge(and charging it again nstead of recycling it), mechanical damage or overcharge



OK and if I store it 10 years on a shelf it will have approx 1.5V and be broken/overdischarged (i.e I will not able to recharge the battery) but still there is no risk that the battery will catch fire as long as I don't put it in my battery charger and try to revive the battery?


----------



## Lexel

lithium batteries catch only fire if the dielectric layer fails
and they are charged

if overdischarged metallic copper crystals grow which can punctate the dielectric layer

a fully charged battery wont be overdischarged from storing 10 years, but will be almost empty somewhere around 3V
even if its overdischarged then there is no danger if you dont charge em again and put them to recycling


----------



## SlowBro904

What happens to the lifespan at higher charging temperatures? I can't find hard numbers anywhere.

I'm building a solar-powered outdoor product with an 18650 and a hot running microcontroller that will be in a plastic enclosure which may (or may not) in the sun. Power usage is expected to only drop the SoC by about 3-5% each day and recharged by solar. Temps are likely to exceed the recommended charging temperature of 45C/113F, perhaps up to 60C/140F. If charging at that high temperature day after day only reduces the overall lifespan by say 10% then I'm comfortable with that.

Anyone know?


----------



## roadkill1109

Would it be wise to discharge an 18650 to the appropriate (storage voltage) or is it okay to just keep it as is after charging?


----------



## Ag76

roadkill1109 said:


> Would it be wise to discharge an 18650 to the appropriate (storage voltage) or is it okay to just keep it as is after charging?


I'd also like to know the answer to this question. I just received new 18650 batteries...4 x Sanyo NCR18650GA, all read 3.52V with my DMM, 3 X Sony 18650 VTC6, 2 are 3.50V, 1 is 3.49V, and 2 X Panasonic NCR18650B, both read 3.54V. Can I store these batteries at their current volts, or should I charge them first?


----------



## Torchmee

Ag76 said:


> I'd also like to know the answer to this question. I just received new 18650 batteries...4 x Sanyo NCR18650GA, all read 3.52V with my DMM, 3 X Sony 18650 VTC6, 2 are 3.50V, 1 is 3.49V, and 2 X Panasonic NCR18650B, both read 3.54V. Can I store these batteries at their current volts, or should I charge them first?


If you want to do it right for long term storage charge or discharge them to 3.6 - 3.7v and store in a cool place, the fridge being an option if the wife will allow it. This will give you max storage life. If they are going to be used in a week or two leave them fully charged. Of course be sure your DMM is reasonably accurate. Some of the top end chargers have a storage mode to adjust the voltage for you.


----------



## Ag76

Torchmee said:


> If you want to do it right for long term storage charge or discharge them to 3.6 - 3.7v and store in a cool place, the fridge being an option if the wife will allow it. This will give you max storage life. If they are going to be used in a week or two leave them fully charged. Of course be sure your DMM is reasonably accurate. Some of the top end chargers have a storage mode to adjust the voltage for you.


I went ahead and fully charged them with the VC4, but it doesn't look like it has a storage mode to adjust voltage. I've thought about running each battery in a light until I lower the voltage to 3.7V, but that seems like a lot of trouble. Maybe I should look for a charger that has a storage mode. Thanks for the help, Torchmee.


----------



## Torchmee

Ag76 said:


> I went ahead and fully charged them with the VC4, but it doesn't look like it has a storage mode to adjust voltage. I've thought about running each battery in a light until I lower the voltage to 3.7V, but that seems like a lot of trouble. Maybe I should look for a charger that has a storage mode. Thanks for the help, Torchmee.


Wow I just looked up the VC4 specs and I see it doesn't discharge battery's. So unless you plan on purchasing another charger you could just go ahead and use them in a light and when you are recharging pull them off when they reach the voltage you want. 

If you are going to be doing it often and want to spend the money then a different charger would be handy. There are a couple available that have an automatic storage function or some allow you to set a desired voltage and then discharge to that voltage. If you get one that will discharge, and there are many, but will not do it automatically you will have to monitor as its discharging and pull the battery when it reaches your desired voltage. All depends on how much you want to spend. Myself or others on here can recommend one if you give a price range you are willing to spend.


----------



## Ag76

Torchmee said:


> Wow I just looked up the VC4 specs and I see it doesn't discharge battery's. So unless you plan on purchasing another charger you could just go ahead and use them in a light and when you are recharging pull them off when they reach the voltage you want.
> 
> If you are going to be doing it often and want to spend the money then a different charger would be handy. There are a couple available that have an automatic storage function or some allow you to set a desired voltage and then discharge to that voltage. If you get one that will discharge, and there are many, but will not do it automatically you will have to monitor as its discharging and pull the battery when it reaches your desired voltage. All depends on how much you want to spend. Myself or others on here can recommend one if you give a price range you are willing to spend.




Torchmee, can you recommend a good charger that will discharge to a preset voltage? I almost went ahead and purchased an Opus BT-c3100/3400 since it seems to be highly recommended on the forum, but I decided to hold off buying more stuff until I can learn enough to be sure I'm getting what I really need. I would probably budget whatever it takes to get the right charger. I don't think I could figure out how to operate the SkyRC M3000, so I probably wouldn't consider that one. After finding this forum, I've been on somewhat of a spending spree, and my wife thinks I've developed an obsession with flashlights. I had no idea it could be this much fun! Thanks for the help.


----------



## Torchmee

Ag76 said:


> Torchmee, can you recommend a good charger that will discharge to a preset voltage? I almost went ahead and purchased an Opus BT-c3100/3400 since it seems to be highly recommended on the forum, but I decided to hold off buying more stuff until I can learn enough to be sure I'm getting what I really need. I would probably budget whatever it takes to get the right charger. I don't think I could figure out how to operate the SkyRC M3000, so I probably wouldn't consider that one. After finding this forum, I've been on somewhat of a spending spree, and my wife thinks I've developed an obsession with flashlights. I had no idea it could be this much fun! Thanks for the help.


The Opus is a great charger and I wouldn't ever get rid of mine but unfortunately it will not auto discharge to storage voltage so you would have to manually monitor it and pull them. However it would be significant a step up from the VC4. Right now as far as I can tell the MC3000 is the only non hobby charger that has an actual storage mode that will discharge to the proper voltage unattended. You can also use the discharge mode and set whatever cut off voltage you want and it will do it unattended as well.

The MC3000 is the most versatile advanced charger/analyzer out there IMO. Yes it is more complicated, expensive and has a greater learning curve than the other chargers but it does so much more! It will be the last charger you ever buy for cylindrical cell battery's. Don't sell your self short on being able to operate it. If you like computers and gadgets, have a little patience and are willing to sit down with the manual and practice you can master it in no time. You have this forum for help and there are lots of Youtube videos. The manual details every mode and setting and a forum member has made a nice cheat sheet for us.

I suggest you download the manual and study it first to get an idea of what it will do. Watch the videos (search SkyRC MC3000 on youtube) and remember it will be easy when you have it to practice on. It does have a "dummy mode" that operates as easy as say the Opus and other less advanced chargers to get you started. As you study up on it you will find comments about teething problems found on the early models but they have been corrected on the latest production ones. I love mine and if I had bought it before the other chargers I have I wouldn't need or own any of them. If you really get into flashlights and battery charging you might as well spend the money on the best now and be done with it. 

If you decide to buy one I will direct you to a distributor here in the US who will handle any warranty issues immediately and will give you an as good or better price than you can get on the China sites. $80 plus what ever the actual USPS shipping is from Ca. It will arrive in 2 to 5 days depending on where you live instead of the 3-4 weeks or more from China with basically no warranty. I got mine to my door for $85. He also sells the Opus if you decide to go that route.

All of the above is my opinion and I have no connection with SkyRc, Opus or the above seller. I just appreciate fine electronics and enjoy helping others do the same. Link to the factory MC3000 manual: http://www.skyrc.com/index.php?route=product/product/download&download_id=168


----------



## Ag76

Torchmee said:


> The Opus is a great charger and I wouldn't ever get rid of mine but unfortunately it will not auto discharge to storage voltage so you would have to manually monitor it and pull them. However it would be significant a step up from the VC4. Right now as far as I can tell the MC3000 is the only non hobby charger that has an actual storage mode that will discharge to the proper voltage unattended. You can also use the discharge mode and set whatever cut off voltage you want and it will do it unattended as well.
> 
> The MC3000 is the most versatile advanced charger/analyzer out there IMO. Yes it is more complicated, expensive and has a greater learning curve than the other chargers but it does so much more! It will be the last charger you ever buy for cylindrical cell battery's. Don't sell your self short on being able to operate it. If you like computers and gadgets, have a little patience and are willing to sit down with the manual and practice you can master it in no time. You have this forum for help and there are lots of Youtube videos. The manual details every mode and setting and a forum member has made a nice cheat sheet for us.
> 
> I suggest you download the manual and study it first to get an idea of what it will do. Watch the videos (search SkyRC MC3000 on youtube) and remember it will be easy when you have it to practice on. It does have a "dummy mode" that operates as easy as say the Opus and other less advanced chargers to get you started. As you study up on it you will find comments about teething problems found on the early models but they have been corrected on the latest production ones. I love mine and if I had bought it before the other chargers I have I wouldn't need or own any of them. If you really get into flashlights and battery charging you might as well spend the money on the best now and be done with it.
> 
> If you decide to buy one I will direct you to a distributor here in the US who will handle any warranty issues immediately and will give you an as good or better price than you can get on the China sites. $80 plus what ever the actual USPS shipping is from Ca. It will arrive in 2 to 5 days depending on where you live instead of the 3-4 weeks or more from China with basically no warranty. I got mine to my door for $85. He also sells the Opus if you decide to go that route.
> 
> All of the above is my opinion and I have no connection with SkyRc, Opus or the above seller. I just appreciate fine electronics and enjoy helping others do the same. Link to the factory MC3000 manual: http://www.skyrc.com/index.php?route=product/product/download&download_id=168



I had ruled out the SkyRC, but you've given me enough good information to make me think I should reconsider. I'll definitely look at the manual to see what's involved. I would also appreciate knowing the U.S. based seller you recommend for either the SkyRC or Opus. You've given me some good options to consider, and I appreciate the help.


----------



## Torchmee

Ag76 said:


> I had ruled out the SkyRC, but you've given me enough good information to make me think I should reconsider. I'll definitely look at the manual to see what's involved. I would also appreciate knowing the U.S. based seller you recommend for either the SkyRC or Opus. You've given me some good options to consider, and I appreciate the help.


I sent you a forum private message, check it.


----------



## Ag76

Torchmee said:


> I sent you a forum private message, check it.



Got it, thanks.


----------



## Gauss163

Torchmee said:


> If you want to do it right for long term storage charge or discharge them to 3.6 - 3.7v and store in a cool place, the fridge being an option if the wife will allow it. This will give you max storage life. If they are going to be used in a week or two leave them fully charged. Of course be sure your DMM is reasonably accurate. Some of the top end chargers have a storage mode to adjust the voltage for you.



Be aware that 3.6-3.7V is far too low for some chemistries (can be below 10% SOC). Generally a good storage voltage is in the range 35-50% SOC, depending on length of storage, ambient temperature, etc. See HKJs charts for Voltage vs SOC for some common chemistries.


----------



## hmjgriffon

Gauss163 said:


> Be aware that 3.6-3.7V is far too low for some chemistries (can be below 10% SOC). Generally a good storage voltage is in the range 35-50% SOC, depending on length of storage, ambient temperature, etc. See HKJs charts for Voltage vs SOC for some common chemistries.




So if you wanted to store batteries for an emergency SHTF type scenario, those should be non rechargeable?


----------



## photonhoer

Torchmee said:


> The Opus is a great charger and I wouldn't ever get rid of mine … If you decide to buy one I will direct you to a distributor here in the US who will handle any warranty issues immediately and will give you an as good or better price than you can get on the China sites. $80 plus what ever the actual USPS shipping is from Ca. It will arrive in 2 to 5 days depending on where you live instead of the 3-4 weeks or more from China with basically no warranty. I got mine to my door for $85. He also sells the Opus if you decide to go that route.


 Torchmee Is your referral offer still valid? I'd like to get one of the SkyRC MC3000 chargers. John


----------



## sll

I've tried various searches with little luck so I thought I would ask. I'll be sure and note the responses this time. 
1- Seems like in one post someone mentioned a charged 18650 should hold a charge for at least a week before starting to drop. Is this right?
2- Why I ask is I have a ~5 month old Fenix 3500 which charges to ~4.2v +/- but drops to 4.15v after 2 days. I charged it back up the first time I noticed but this time I'm going to keep watching it. Is that rate of voltage drop high? Suggestions?
3- Will the battery continue to operate and what kind of service time would I expect? 
4- How do you determine when a battery is at the of life?
5- Any additional information is once again greatly appreciated!
Thanks!


----------



## ven

sll said:


> I've tried various searches with little luck so I thought I would ask. I'll be sure and note the responses this time.
> 1- Seems like in one post someone mentioned a charged 18650 should hold a charge for at least a week before starting to drop. Is this right?
> 
> **Pretty much, but the initial termination voltage will drop slightly and settle.
> 2- Why I ask is I have a ~5 month old Fenix 3500 which charges to ~4.2v +/- but drops to 4.15v after 2 days. I charged it back up the first time I noticed but this time I'm going to keep watching it. Is that rate of voltage drop high? Suggestions?
> 
> **Not too sure how measured and if measured with same MM(multi meter/charger). Chargers spec tend to be + or - 0.05v, which is 4.15v to 4.25v. After charging, the voltage will drop slightly. For example, fresh off the charger at 4.2v, can settle to 4.18v.
> 3- Will the battery continue to operate and what kind of service time would I expect?
> **After the initial drop is important, does it stay around 4.15v or continue to drop at the same rate. If the latter then yes the battery is tired.
> 4- How do you determine when a battery is at the of life?
> **Usually when the voltage does not hold after settling , so once the V gets near 4.1v after charging(presuming the charging initial V is 4.2v ) then for me, the cell is past its best. At 4.1v, you still have roughly 90% charge................plenty use in the cell providing it does not continue to drop.
> 5- Any additional information is once again greatly appreciated!
> Thanks!



^ answered above my thoughts in between Q's

**Would not be over concerned at this stage, if your going to store the cell, aim more for around 3.7 or 3.8v(if months rather than weeks). Other than that, dont get too hung up. Lots of my cells get used/charged daily so it will take a while for me to actually see Voltage drop. To try and explain better, i will use a work cell which is a samsung 30Q. Now this is around 4.2v terminated, measure after coming off the opus bt c100 it shows 4.18v. This cell goes straight into a 6p ready fro the next day. Its gets used the following day for X amount of time(variable). Back on charger and may read anywhere from 3.6v to 4.0v............repeat! So not too easy in that respect, if the term V off the charger is lower i will notice. Obviously i will notice if the cell does not last me my typical use or the V is very low when put back on charge to top off. So i dont get too hung up on the cell V, i take note and until something obvious................gets used. I do take note of the IR reading(internal resistance), this also has not really changed. I do take this with a pinch of salt.

The Fenix cell will either be a sanyo GA inside or an LG. Both good cells, at 5m of age it should be fine(use dependent but would have to have many discharge/charge cycles in that time to effect). Measure the V after a couple of days, then a week, then 2 weeks to get a rough idea. I would have thought it wont drop much if anything lower than 4.15v. Just make sure what your measuring on is the same device for consistency. Other than that, use and enjoy


----------



## sll

Thanks for the detailed reply. I have made notes so I don't have to keep asking. The battery was at 4.14v yesterday and is 4.12v this morning. I use the same DVM and the other batteries typically settle at 4.17-4.19 after several day days. I do notice the XTAR VP2 charger will occasionally stop at 4.18v to 4.19v. Sometimes I'll put the batteries back into the charger to get them up to 4.2. Is this "topping off" the batteries [1] Really that necessary since they are at 98-99% capacity? and more importantly [2] Is this detrimental to the batteries? 
Thanks again!


----------



## terjee

The topping matters too little that I'd care, both in terms of how much more energy you can fill, and also in terms of negative effect. I wouldn't bother to do it.

If you absolutely need as much juice as you can get into the battery, you can charge at a slower rate.

The faster you charge btw, the faster the voltage will drop after charging. You could perhaps see something like charging at 2A dropping from 4.2 to 4.17, and charging at 0.5A dropping from 4.2A to 4.19V. It doesn't matter too much though.

Not charging too fast (such as a weak battery at 2A or more) would not be good for the battery. I stay at less than 1A for an 18650, unless I know it'll be comfortable taking more. VTC-series for example, I'll charge at 2A.

If you want a quick an easy way to keep an eye on the health of a battery, then a charger showing internal resistance can be a good way to go about it. I can't recall if the Opus does that (I don't think so, but I could be wrong). Depending on your level of interest and how much you'd be willing to spend, the MC3000 or SC4 could be something to consider (the latter will default to charge at 2A though).

Analyzing the available capacity by doing a charge/discharge cycle, is also useful in determining battery health.


----------



## sll

I charged the questionable battery and one other at 0.5A today and the both had 4.20 V an hour after coming off the charger. Previously I had been charging at 1.0A but maybe I'll cut back to the 0.5A. Any problems with that?

The questionable battery was at 4.10V before charging it today and I plan to monitor it for voltage drop. Is the consensus if I charge it one day before use that it should still have >90% capacity and function fine for the one day?

Thanks


----------



## hkusp9

terjee said:


> The topping matters too little that I'd care, both in terms of how much more energy you can fill, and also in terms of negative effect. I wouldn't bother to do it.
> 
> If you absolutely need as much juice as you can get into the battery, you can charge at a slower rate.
> 
> The faster you charge btw, the faster the voltage will drop after charging. You could perhaps see something like charging at 2A dropping from 4.2 to 4.17, and charging at 0.5A dropping from 4.2A to 4.19V. It doesn't matter too much though.
> 
> Not charging too fast (such as a weak battery at 2A or more) would not be good for the battery. I stay at less than 1A for an 18650, unless I know it'll be comfortable taking more. VTC-series for example, I'll charge at 2A.
> 
> If you want a quick an easy way to keep an eye on the health of a battery, then a charger showing internal resistance can be a good way to go about it. I can't recall if the Opus does that (I don't think so, but I could be wrong). Depending on your level of interest and how much you'd be willing to spend, the MC3000 or SC4 could be something to consider (the latter will default to charge at 2A though).
> 
> Analyzing the available capacity by doing a charge/discharge cycle, is also useful in determining battery health.



whats the typical resistance for an unprotected 3500 mah 18650 LG battery and how close do they need to be to each other to be "matched"?


----------



## dragosios

Should in the tens of miliohoms range.
You should select the most closest ones in your batch. Of course, financial constrains will limit your choice, also cells age more or less the same if they are used and not used the same.


----------



## terjee

One bit of trouble is that if you're matching up cells, you'd need to check both internal resistance and capacity.
Most people just build packs from cells purchased together without added checks.


----------



## xdayv

terjee said:


> One bit of trouble is that if you're matching up cells, you'd need to check both internal resistance and capacity.
> Most people just build packs from cells purchased together without added checks.


How to check for internal resistance?


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## Budman231

I wanted to share this video. It explains protected vs. unprotected 18650 cells. He does an excellent job explaining the dangers of over charge and over discharge whole showing how the protection circuit works.

https://www.youtube.com/watch?v=1rg3ZWxBNUE&t=31s

Bud


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## jimbo231

If I'm storing @ 3.7v and they drop below that over time. At what no load voltage should they drop to before I charge them back up to 3.7v? Also is that the proper thing to do... just charge to 3.7v? Will there be any negative effects by just bringing back up to 50 % capacity?


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## david.allie

Torchmee said:


> The MC3000 is the most versatile advanced charger/analyzer out there IMO.
> 
> If you decide to buy one I will direct you to a distributor here in the US who will handle any warranty issues immediately and will give you an as good or better price than you can get on the China sites.



Torchmee, who in the US are you recommending for a purchase of the MC3000? I’d like to get one. TIA


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## MarioJP

Question. So this is my first set of 18650's and they're Panasonic 18650B, and after more than 2 years of use, i have noticed unsual heating on one or more cells during the constant voltage phase. Now i am not completely sure if the heat is coming from the charger and maybe losing my mind, but normally as the current begins to drop so does the temps. As the current gradually drops on all 4 cells the first 2 feels cooler but the third cell feels warm. But the last seems to be slowly heating up and does not seem to cool, and also the current drop on that cell drops much slower than the other 3. It's dropping but barely. Should i be concerned about this?

Thanks.


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## fmc1

MarioJP said:


> Question. So this is my first set of 18650's and they're Panasonic 18650B, and after more than 2 years of use, i have noticed unsual heating on one or more cells during the constant voltage phase. Now i am not completely sure if the heat is coming from the charger and maybe losing my mind, but normally as the current begins to drop so does the temps. As the currently gradually drops on all 4 cells the first 2 feels cooler but the third cell feels warm. But the last seems to be slowly heating up and does not seem to cool, and also the current drop on that cell drops much slower than the other 3. It's dropping but barely. Should i be concerned about this?
> 
> Thanks.



How's the internal resistance?
Is the C. Current over 1.0A?
Let's start with the basics.

Frank


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## MarioJP

fmc1 said:


> How's the internal resistance?
> Is the C. Current over 1.0A?
> Let's start with the basics.
> 
> Frank


1.5A charging
I'll check the resistance. I'll get back to you on that.

The cell in question has cooled and is about to terminate it is currently around 60ma

Charger: MC3000


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## fmc1

MarioJP said:


> 1.5A charging
> I'll check the resistance. I'll get back to you on that.
> 
> The cell in question has cooled and is about to terminate it is currently around 60ma
> 
> Charger: MC3000



The MC3K checks the resistance at the start of a charge. It's the last line in SOV. You don't have to wait until the charge is finished.
If it's over 200 ml ohms you have you answer.


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## MarioJP

fmc1 said:


> The MC3K checks the resistance at the start of a charge. It's the last line in SOV. You don't have to wait until the charge is finished.
> If it's over 200 ml ohms you have you answer.


Cell IR
1: 76m
2: 74m
3: 77m
4: 78m (cell in question. Put tape to mark it)

So yea, i don't know what is going on. All i know during the constant voltage phase that cell was starting to get warmer while the other three was cooling down. They were all discharged and charged at the same time and with the same current.

Update

I know the charge going into the cell does not reflect the total capacity. But what happens when you have a cell that exceeds the rated capacity for Li-ion. After using these cells for more than 2 years, never seen the mAh exceed 3400 until now. I let the cells rest overnight and there seems to be no indication of problems after measuring the voltage the following day as it was at 4.19-4.18v. But the extra mah put into that cell raises questions. Is this part of normal wear and aging and losing it's eficiency or first sign of issues?

Just want to be assured that these cells won't go boom.

Thanks


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## Dynapoints

Torchmee said:


> If you decide to buy one I will direct you to a distributor here in the US who will handle any warranty issues immediately and will give you an as good or better price than you can get on the China sites. $80 plus what ever the actual USPS shipping is from Ca. It will arrive in 2 to 5 days depending on where you live instead of the 3-4 weeks or more from China with basically no warranty. I got mine to my door for $85. He also sells the Opus if you decide to go that route.
> 
> 
> 
> Hi there!
> I am new to the world of 18650 batteries. I have been reading up on explosions and fires and good chargers. Yesterday the big news story in Tampa was a vape the exploded started a fire that led to a fatality. Sober reminder i have to take care of this.
> Please send me the info on the distributer of the mc3000 charger.


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## klrman

Is it harmful in any way to charge lithium batteries to around 90% such as 4.1V before using? I always feel better under charging them a little to keep the stress levels down, but I don't know for sure if I am doing the right thing.


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## SilverFox

Hello Klrman,

If you don't need the capacity your batteries will reward you by giving you improved cycle life. No problem at all.

Tom


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## Gauss163

It's beneficial - not harmful - to use shallower depth cycles. Further gains can be had by _centering _cycles around the half-full point (e.g. using 10% - 90% region) since this minimizes the time the cell spends at extreme voltages (where accelerated degradation occurs). See this post (and its links) for much further discussion (including charts and studies). I meant to update some of that info (and simplify it a bit) but - alas - a moderator locked the thread.


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## klrman

SilverFox said:


> Hello Klrman,
> 
> If you don't need the capacity your batteries will reward you by giving you improved cycle life. No problem at all.
> 
> Tom



Hello SilverFox,

Thanks for the reply. Great, I was always hoping it was a good idea to do so, but it feels much better knowing for sure!


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## klrman

Gauss163 said:


> It's beneficial - not harmful - to use shallower depth cycles. Further gains can be had by _centering _cycles around the half-full point (e.g. using 10% - 90% region) since this minimizes the time the cell spends at extreme voltages (where accelerated degradation occurs). See this post (and its links) for much further discussion (including charts and studies). I meant to update some of that info (and simplify it a bit) but - alas - a moderator locked the thread.



Thanks for the info Gauss163, I going to read it all and try and absorb everything. I got my MC3000 recently and will make it work for me as much as possible.


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## ktate749

Am I correct in assuming, do not use the "Charge Test" on the Opus C3100 for a 18650 battery?

Thanks


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## terjee

ktate749 said:


> Am I correct in assuming, do not use the "Charge Test" on the Opus C3100 for a 18650 battery?



Shouldn’t be a problem.

It’ll just do a charge, discharge, and charge again, giving you information about what capacity you got during discharge.

Also, see here: http://lygte-info.dk/review/Review Charger Opus BT-C3100 V2.1 UK.html

(Disclaimer: I don’t currently own this charger)


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## Gauss163

ktate749 said:


> Am I correct in assuming, do not use the "Charge Test" on the Opus C3100 for a 18650 battery?



Doing an occasional deep cycle to test capacity isn't going to cause much extra degradation to an optimally managed cell (as long as the capacity tests amount only to a small fraction of the number of equivalent full cycles)


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## ktate749

Looking at the data sheets for my Panasonic and Sanyo 18650 batteries, they have a value of 3.6V for the "Nominal Voltage". What are they referring to?

Thank
ktate749


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## terjee

ktate749 said:


> Looking at the data sheets for my Panasonic and Sanyo 18650 batteries, they have a value of 3.6V for the "Nominal Voltage". What are they referring to?



The nominal voltage basically just means that’s roughly the voltage they spend the most time at during discharge. You charge them to 4.2V, but it drops much more quickly down from there, than it does from 3.6V.

It’s basically just the same as car batteries having a nominal voltage of 12V, yet you charge them to 13.6V or 14.4V, depending.


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## ktate749

Thanks terjee clears it up.


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## degarb

One cell phone app, on playstore, claims 55% charge does zero damage to cell. But I doubt that. Moreover, isn't there a 3 year shelf lifespan on Lithium Ion Chemicals in the cells?

Rather than .025% damage at 70%, I would feel better, if the chemist that makes the cells, had a voltage charge to kilo amp hour duty over entire cell life at 1 amp and .350 amp discharge.

While I am a skeptic as to wisdom of undercharging, I do hope it will make people think about demanding higher cell capacity formats.


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## Gauss163

degarb said:


> One cell phone app, on playstore, claims 55% charge does zero damage to cell [...]



Generally using shallower cycles will prolong life, but it certainly won't completely eliminate cycle degradation. Further, to maximize longevity, besides using shallow cycles you should _center _them around 50% SOC, e.g. if you're going to use cycles of 50% depth then instead of using 0-50% you should center them, i.e. use the 25-75% region. See this post for further details, including graphs of results from studies on such matters. 



degarb said:


> Moreover, isn't there a 3 year shelf lifespan on Lithium Ion Chemicals in the cells?



No, quality cells have much longer life if stored properly. But that may apply to certain _installed _batteries that are subject to external parasitic loads that could drain them much quicker than self-discharging would. In particular if they drain too low it may no longer be safe to charge them so the BMS will prevent such.


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## etc

djdawg said:


> What the voltage of two 18650 ..........is it more than 9 volts ?
> LOL.....I know nothin
> I have a Malkoff M-61 drop in that I want to use in a two 18650 batt body ...........can I ??




Malkoff M61 in a 2-cell body, with two 18650 is a very good idea. You will get extra lumens and great runtime. 

The current will be lower, meaning the cells will be hit less. Generally the more batteries you include, the less each one is drained individually.

M61 series of course can only take up to 2 Li-Ion cells. Other Malkoff drop-ins can take up to three Li-ion cells. E.g. the Hound Dog.


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## etc

Gauss163 said:


> Generally using shallower cycles will prolong life, but it certainly won't completely eliminate cycle degradation. .




Interesting point you make. I've always thought the same thing also. I agree.
On the one hand, you don't want many recharge cycles but it appears that shallow cycles are better than discharing the thing down to 2.5V - beyond empty.


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## etc

Illum said:


> I would prefer to have protected cells in my collection because they protect from overcharge and overdischarge by disconnecting the battery



Yeah. *But*, one huge problem with protected cells is that they suddenly go out. In a multi-cell configuration but even 1x18650. The circuit kicks in and you are down. 

Now imagine you are in a cave. Or hanging on a mountain. Or in any number of other dangerous situations where suddenly you lose all light. There is no warning period, it goes "Poof". 
Yeah, I realize you have a spare that's 30 seconds away but that can be critical.

This is one *huge * advantage of running 1x18650 lights off *un* protected cells since you will get a long, gradual decline into the sunset.

M61 case in point, or 18650 Hound Dog.

That is one huge advantage of running your lights off 123s, as expensive as that might be. They don't go out in a nanosecond.


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## WalkIntoTheLight

etc said:


> This is one *huge * advantage of running 1x18650 lights off *un* protected cells since you will get a long, gradual decline into the sunset.



It depends on the light. Some lights have built-in low-voltage protection. However, those lights usually have a period of step-downs, which give you plenty of warning. For example, Zebralights have a low-voltage protection at 2.7v, but they also step-down well before you're left in the dark. In the case of Zebralight, the built-in LVP would kick in sooner than the 2.5v LVP of a protected cell.

With most 1x18650 lights that don't use boost drivers, it would be tough to actually be left in the dark with a protected cell. The voltage is just too low for the forward voltage of the LED.


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## etc

WalkIntoTheLight said:


> It depends on the light. Some lights have built-in low-voltage protection. However, those lights usually have a period of step-downs, which give you plenty of warning. For example, Zebralights have a low-voltage protection at 2.7v, but they also step-down well before you're left in the dark. In the case of Zebralight, the built-in LVP would kick in sooner than the 2.5v LVP of a protected cell.



None of my Surefires or Surefire clones or Malkoff MDx-series have built-in low-voltage protection. I don't have any Zebralights. Neither do most people that build LEGO assemblies.



> With most 1x18650 lights that don't use boost drivers, it would be tough to actually be left in the dark with a protected cell. The voltage is just too low for the forward voltage of the LED.




The cell declines to the voltage where the PCB is triggered and you go from xxx lumens to zero lumens in a nanosecond.

That is how every protected cell has worked with every Lego light with every P60-drop-in module I've had in the last 10 years. This is kind of good as it protected the cell from overdischarge, that's the point of it. It's not so good if you critically need light that very second. Case in point, you are an LEO holding a suspect or suspects in a dark basement. Your lights go out as the cell hits the threshold for cutting out, whatever it is, 2.5V I assume, and that jeopardizes things. I can think of 100 and 1 situations like that.

Not only does an unprotected cell give you some warning by gradually declining but in an emergency, when you have no spare to reload, you can run it down as low as you have to maintain light. Quality 18650 only cost $7 these days, we are talking 18650 3400 mAh. I remember when they first came out, which seems like yesterday and were close to $20/each.

Really risking $7 is not that much more expensive than primaries that are 2 bucks a piece retail. Use it several times and you break even.


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## WalkIntoTheLight

etc said:


> The cell declines to the voltage where the PCB is triggered and you go from xxx lumens to zero lumens in a nanosecond.
> 
> That is how every protected cell has worked with every Lego light with every P60-drop-in module I've had in the last 10 years. This is kind of good as it protected the cell from overdischarge, that's the point of it. It's not so good if you critically need light that very second. Case in point, you are an LEO holding a suspect or suspects in a dark basement. Your lights go out as the cell hits the threshold for cutting out, whatever it is, 2.5V I assume, and that jeopardizes things. I can think of 100 and 1 situations like that.



My point is that with (non boost-driver) lights, they will already be very dim by the time the protected cell shuts off at 2.5v. For example, an XP-L emitter at 2.5v will be barely lit, if at all. IOW, there's not going to be much practical difference between running the light with a protected or unprotected cell.

This is completely different if your light has a boost-driver, such as a Zebralight. But, AFAIK, those kinds of lights all have built-in LVP anyway, so it will still be the same regardless of your cell protection.


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## Gauss163

etc said:


> Interesting point you make. I've always thought the same thing also. I agree.
> On the one hand, you don't want many recharge cycles but it appears that shallow cycles are better than discharing the thing down to 2.5V - beyond empty.



This works because the shallower cycles (centered around 50% SOC) serve to keep the cell away from extreme voltages (which accelerate degradation). Generally to prolong life you want to minimize the amount of lifetime the cell spends at extreme voltages (and temperatures) - both in cycling and storage. Even small changes can yield large improvements because the degradation processes are nonlinear. Follow the link I gave above for further details.


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## AlpineBatteries

This is such an fascinating and illuminating thread. I just bought a new Lenovo laptop, and among the pre-installed Lenovo firmware is a function called "Conservation Mode". When activated, it prevents the battery from charging beyond 60%. Since I rarely unplug and carry my laptop around for any extended period of time, I keep the setting on. If I know I'm going to unplug for a while, then I'll deactivate the setting and charge it all the way up first. 

Another interesting tidbit is that my father just got a Tesla Model 3, and told me that Tesla recommends not topping off the battery. So it's nice that the company is spreading the word about best practices for Li-Ion care.


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## Monocrom

I've never experienced any issues with topping off my 18650 and similar cells. One of the biggest things is not to use a fast-charger. Might be annoying waiting 5 hours to charge up one 18650, but patience is worth it. Last thing you want is an 18650 becoming the world's greatest hand-warmer the instant you take it off of a charger.


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## WalkIntoTheLight

Monocrom said:


> I've never experienced any issues with topping off my 18650 and similar cells. One of the biggest things is not to use a fast-charger. Might be annoying waiting 5 hours to charge up one 18650, but patience is worth it. Last thing you want is an 18650 becoming the world's greatest hand-warmer the instant you take it off of a charger.



Yeah, I think some people get too anal about managing their cells to perfection, including myself sometimes. Though, I'm trying to be less strict about it, and just charge and use most of the time. I usually try to charge at 1 amp, because I'm not in a big hurry. A lot of chargers now seem to default to 2 amps, which is okay for high-drain cells, but it's still a little more stressful than 1 amp.

If I notice the voltage on the charger is up to about 4.1v, I'll often pull the cells off early. That's about a 90% charge, which is fine for most of my use. Lately, though, I'm usually letting it go to the full 4.2v. Again, trying to be less anal. Most of my cells will probably tire out from age, before they wear out from cycle counts.

Note that charger specs are usually 4.20v +/- 0.05v. That means that some chargers might charge your cells up to 4.25v, which IMO is putting more stress on them than you probably want. You'll get about 5% more capacity out of them, but probably lose 25% of the cycles.

As a rough rule, you can charge up to 4.3v, and lose half your cycles for a 10% gain in capacity. Or, charge to 4.1v, and double the number of cycles, for a loss of 10% capacity.


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## Scimmy

Budman231 said:


> I wanted to share this video. It explains protected vs. unprotected 18650 cells. He does an excellent job explaining the dangers of over charge and over discharge whole showing how the protection circuit works.
> 
> https://www.youtube.com/watch?v=1rg3ZWxBNUE&t=31s
> 
> Bud




Thanks for the video, very interesting.. They sure can be dangerous if not treated properly


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## doctordun

Ok, I encountered a question trying to determine how long a protected 18650 cell rated at 3100mAh would power a 5 volt led light running at a drain of .07 amps. In actually testing I got 24 hours before the light stopped. A second test with the light function at .23amp draw and it lasted around 10 hours.
I have read that 18650 batteries have from 2 amp hours to 3.5 amp hours of available power.
In a protected battery, I would assume that numbers would be lower because of the protection circuit.
I would like like to get access to more data and perhaps a spreadsheet with formulas to play with.
How much does the amp hours vary with the mAH ratings? Does the protection circuit limit a percentage of available power output and if so, how much.
Any and all information would be most welcome.
Thank you. all.
Albert


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## SilverFox

Hello Albert,

Each cell manufacturer and sometimes each batch of cells can vary in capacity. The labeled capacity on the cell is often "optimistic." This means that if you want accurate information you end up having to do some cell testing yourself.

HKJ has done a lot of testing and posts results frequently. In addition he has a website that lists the results from the various tests. If you can find your brand you may be able to get an idea of how long your cell will last under various loads.

Right now you have one run with a drain of 70 mA that lasted for 24 hours. This would give the cell capacity starting at 70 x 24 = 1680 mAh. Your second run had a drain of 230 mA for 10 hours giving a cell capacity starting at 230 x 10 = 2300 mAh. At first glance it would seem your first run was done with a cell that wasn't fully charged...

The capacity of a cell is related to how fast the current is used from it. There is a point where the cell heats up and energy that could be used is consumed producing heat. I don't think your loads are in that range so something else is going on with the differences in run time.

It looks like you need to do a few more tests involving runtime to get a better idea of how your cell is performing. Once you have that down you can repeat the testing using other cells to see how they match up to what you have now.

Tom


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## wayben

Great thread, lots of useful info!!!


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