Charging Lithium 18650 batteries

[Ian_Edwards]

Some time ago I converted all my small LED torches from 3 AA or it could have been 3AAA batteries to one 18650.
This conversion has worked well, the only downside is that you have to remove the 18650 to recharge them.
I've been checking the torches to make sure that they are all working and fully charged, prior to the dark nights ahead.
One battery is refusing to charge, the display on the charger says it's supplying 5.163 volts and zero amps, with the battery connected. With the battery disconnected it indicates 5.212v, and of course zero amps.
Is there any safe way of giving the battery a slightly higher voltage to "kick start" the charging process?
I suspect that the torch has been left on and completely flattered the 18650, or is it completely toast?
The battery is a Ledeak 2500mAh, sold by Amazon.

 

[noelex]

The maximum charging voltage for an 18650 lithium battery should be at or below 4.2V.

 

[toothless]

id ditch it, if it isnt taking a charge and is a bare cell then it is probably dead. they have very little circuitry for you to have damaged and this sounds like a dendrite shorting the cell. no point hanging on to it if it doesnt work and is a possible fire hazard...

 

[Cerebus]

id ditch it, if it isnt taking a charge and is a bare cell then it is probably dead. they have very little circuitry for you to have damaged and this sounds like a dendrite shorting the cell. no point hanging on to it if it doesnt work and is a possible fire hazard...

I agree. The top of these batteries have a ‘vent system’ you may be able observe.

Does it smell differently to other good batteries? Not a silly question; it is an indicator of bad things happening I have been told.

No battery lasts forever.

Cheaper ones certainly do not.

I have not purchased one in a few years; they used to be relatively cheap.

I would recycle and buy a new one.

 

[Refueler]

The maximum charging voltage for an 18650 lithium battery should be at or below 4.2V.

??? That all depends on the 18650.

There are basically two voltage models of 18650 .... and if you have the 4.2v model - then charge should be at 4.3 or slightly higher voltage, if you give 4.2 - then the battery will resist and never reach full charge.

The best way to charge such - is to use a User programmable charger such as the Li chargers we use for models. A budget charger ... about $25 for a B6 or similar can not only charge these cells - but can also charge literally any other rechargeable battery you may have .. with full charge cut-off detection.

Back to OP's 18650 ... looks like thats all over for that cell .... if its showing such a high voltage - then somethings definitely wrong either with the measuring tool or the cell itself. You cannot push higher voltage to a Li to kickstart it ... unlike a NiCd .. all you do is make it worse.

 

[fredrussell]

…and when you replace the duffers, buy from a reputable source. There’s an enormous amount of fake ‘name brand’ cells out there.