Mysterious 18650 battery, Should I try charging it?

So I took apart a broken RC Helicopter, and when I got to the battery pack I found what appeared to be two 18650 cells wired together in series, a suspicion helped by the fact that the battery pack was rated at 7.2 volts, which would be the voltage from two 3.6 volt lithium batteries. So I separated the two cells, and compared them to my two 18350 batteries (which when stacked end to end are the same length as an 18650) and the length was a dead match.

So I'm certain these are 18650 cells, and what I'm wondering is would it be safe to charge these with my lithium battery charger? Theres no branding on the batteries a anywhere, but I would assume since they are in a consumer product that they would meet some quality standards, and might be safe to charge?

I'm really just looking for some feedback so I can work up the nerve to plug in some un-branded batteries

Additional: I tested them on my multimeter, but couldn't get even the tiniest amount of voltage off them. Don't know if thats important or not.

Thanks!

Heres a picture of the battery:

I would do it personally. If the dimensions are the same and the voltage is the same they will at least work in your charger providing the chemistry is the same... which is the only gamble. I have charged 18350 batteries in a 16340 charger. I've also charged batteries from solar lights which have a green sleeve and some chinglish on them, ultra low capacity 600/300mAh but they're really just NiMh AAs.

If you have a charger you don't like very much then maybe use it, in case it goes bang.

Just noticed you also said it reads no voltage - it's either totally dead then or is a protected cell which has shut down. Charging should rejuvenate it.

lol got this intellicharger chummy thingie that charges just about anything! bet it would make them soar or blow up at the very least!

ru124t said:

lol got this intellicharger chummy thingie that charges just about anything! bet it would make them soar or blow up at the very least!

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That's a good point - does battery chemistry matter or is it purely to do with the volts it puts out?

I have a "NiMh" charger but what's to stop me charging NiCds in it? (Lol NiCds, remember them? Pieces of sh*te!)

If battery chemistry is not an issue, and the volts just have to match, then Blarg probably can put this mysterious blue battery on a nice slow charge.

/off to do research

It's a lithium Ion battery, it said so on the wrapper that both batteries were in. One of the cells has a rusty spot and it looks like it ruptured a bit, so I wont use it, but the 2nd cell is pristine.

I think I'll put it in my charger and put it inside a nice steel ammo box I have, just in case it does decide to explode on me. It would be nice to have an 18650 cell for some projects.

Maybe I'll also charge it out on my deck....

Freakin right man! If you're gonna have shrapnel , Might as well have that good steel from an ammo box! While your at it, put a nice handful of nails and some stainless ball bearings in there too ! lmao Excuse please Mr Blarg but I am the newfie here and I wouldn't even try and charge that thing! Get my point???

Nah that lithium battery would't explode with enough force to turn a steel box into shrapnel. Dent the crap out of it maybe, but not shred it.

Then charge up the rusted one too! Just as well to have a big explosion while you're at it!

Meh I just ended up ordering a sony 18650 off ebay

well that was an anti climax.

Blarg King said:

Meh I just ended up ordering a sony 18650 off ebay

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Just fyi...I had two DeWalt 18v Lithium packs (the old kind with the short neck, not the new slide-on ones) that I discharged at work then let sit drained for over a week. That was the death of them as packs, but I broke them open and they were full of Sony Olivine SE US18650FT's - 1100 mAh.

All of them recovered as individual cells. But, apparently, the pack circuitry was telling the charger they were no good.

G

I pulled my two batterys from a helicopter also and straight in the nitecore charger they went! i think they are LiPo batts and possibly a type of IMR battery (rated @ 1500mAh), they can put out quite a few amps!,
I think if they were goin to explode they would have done so with the cheapo charger and power adapter while charging them with the helicopter charger and would be less likely with a good Hobby Charger

Yes but these batteries have been sitting for a year without being charged or discharged so Im concerned they may not take well to being charged after being dead for so long.

as long as you do it like planned I see no problems-
a nitecore ' knows' what batts there are and will safely charge them if then can be charged back up. and YES its more often a prob with the PCB or just one battery from a batt pack-
I would however agree to charge like you said and do it outdoors-

I have several PC shops saving batt packs from laptops for me..

I twist off the tabs and polish the ends with my dremel tool- most work just fine-

hk

Bare cell with no PCB reading 0V? Throw it away at recycling center, don't attempt to charge. Below 2.6V is bad for Li-ion.

If you do try to rescue it, do a full range of discharge and capacity tests to ensure that you know the limits of the cell.

If the cell feels warm during charging, disconnect and let it cool off outside. Then take it to recycle center.

Some intelligent chargers will attepmt to charge Li-Ion at very low voltage with a very small current (like, 50mA) until it reaches the low end of the Li-ion charging curve, adn then it proceeds as usual. Don't know if this applies to cells that are actually at 0V...

If you deal with laptop packs, you get 6-9 cells per pack, so throwing away any string that contains dead cells or low voltage cells is an easy way to eliminate possible problem cells.