After first laptop battery pull questions

So I pulled apart an old Toshiba laptop battery and got 6 pink CGR18650CA’s I could not find a lot of info on these. Also I put each into my xtar charger and 4 read some life 2 did not register at all. I currently do not have a multi meter so are the 2 that showed no reading any good or just toss them? Also I slightly damaged the casing on 1 while removing it. It is slight and the metal is not exposed as it is on the top. This was a nice learning experience for sure.


Do a capacity test on the “good” ones and toss the dead ones.

The good ones might be high mileage, but still perfectly usable in low-stress lights.

Data sheet for battery you listed:
2200mAhr cells, pretty typical for laptops. Best I ever found were 2600mAhr ones. Agreed, toss the ones that won’t charge.

The standard advice is to charge them and measure the voltage a couple weeks later to see if they are holding a charge or not. Since you don’t have a meter I guess you get what you get . . .

Just curious, what’s your plan for them, that is where do you plan to use them.

Be aware that lithium cells @ below 2.0v for a long time have a high chance of permanent damage that may make them more risky. If they heat while charging, or don’t hold a charge for a good while you should strongly consider discharge and discard. There is extensive discussion on this in the forum.

I think using laptop pulls without a DMM is living dangerously since there’s no way to know what the actual cell voltages are. Actually….I think using any rechargeable lithium cells without a DMM is living dangerously :frowning:

Thank you for the concern. I am aware of the dangers. Perhaps I got a little over excited. I will get a DMM tomorrow and post what I find out.

Picked up a DMM today and the 2 batteries that would not register were at 1.48 and 1.41 the other 4 cells read between 3.23 and 3.45 so I now have 4 good cells. Are there any other signs or things I should look for such as getting too hot while charging or not holding a charge? Thanks for the input

Even a basic DMM from Harbor Freight, or Home Depot, will give you a clue.

The problem with li-ion cells and danger, stems from the older chemistry of lithium-cobalt. The copper based separator, when the cell is left in a depleted state for extended time, forms copper dendrites and upon recharging, can create a short, heating the electrolytes up and venting with flame.

Japanese/S.Korean manufacturers have moved on to hybrid chemistries, which have different internals and higher thermal runaway temps, so venting with flame upon recharging is less of a concern today. We’re also talking weeks, months, even years in a discharged state.

If you take a cell, even a li-co cell, down to 2.00v and then quickly charge it back up, you might shave some cycles/capacity off of it, but you won’t have any major concerns beyond that.

With laptop packs that are forgotten for a long while, one has to be careful. I’ve salvaged two Sony VAIO packs and one HP, pitching some and keeping many.

My 16 Sony 2100mAh 18650s are date coded 2002 and I have about 75% capacity left, but I don’t stick them in my Emisar D4, either. They get light duty.


Someone here once mentioned this and I’ve been doing it since then. When you retrieve the cells, before you do anything with them, check the voltage(s) straight out of the pack with the DMM. Then, write the voltage on each cell with a Sharpie marker. That way, you will know which cells were the strongest and which were the weakest.

I think, if you pay attention while disassembling, you will find that the two “dead” cells are connected in parallel to each other and are the cells that the pack uses to run its internal electronics. So, when the pack is not in use, those cells are still being drawn from, and that’s why the voltage goes down further on those cells. In fact, a lot of times, the pack itself will be considered “dead” by the self-monitoring circuit, because of those two cells going dead! The rest of the cells may be in good condition, depending on age and usage pattern.

In a recent laptop pull I did, I got 2 usable cells and 4 duds. The 2 usable ones were each in parallel with a 0V cell. I have cycled them, charged them, and put them aside to see what voltage they read in a couple of weeks. Anything less than 4.15V and they will get tossed.

That’s …odd! :open_mouth:

I thought so also. I would have given the same advice you did before seeing it for myself. They other two may not be great either, time will tell.

I’ve also saved a few laptop batteries with good condition.
I’m just curious what you do with the rest of the nickel that is left on the batteries after you’ve removed the nickel with pliers.

Leave it, file it down, doesn’t really matter much.

As long as it’s not sharp enough to cut you…

Try and smooth it as much as you can. I had one snag the spring on my Convoy S3 and pulled it off the board when I unscrewed the head.

I used a Dremel with a light sanding bit on it and worked great. Also I plan on testing the voltage in a couple more days and see if its holding. Writing on them with a marker is a great idea and I plan on doing that when I test them. Thanks