Got some new 14500 batteries in, one of them measures ~.64 volts - is it safe to charge?

Hi,

I got a batch of four Efest IMR 14500 batteries in today, so I wanted to charge them.

As I’ve been “taught” (reading here and elsewhere), to be safe, I measured the voltage of each battery before putting them into my charger.

The 1st 3 each measured about 3.79V, but one of them, the last one, only measured ~.64 volts :(…

I’ve started charging the 3 batteries, but not the one with the low voltage, and wanted to check here first.

Is that battery safe to charge? Or is it just bad/defective? I think that it is not, but wanted to confirm.

Please advise.

Thanks,
Jim

NO! don’t ever charge a cell that is below 2.5V (I use 3.0V as my cutoff voltage when salvaging laptop packs)

But, if the cell is a protected cell, the protection circuit may have tripped and needs to be reset.

Trash it!

Hi,

The battery is this one (Efest IMR 14500/700 mAh):

http://www.ebay.com/itm/390541474942?ssPageName=STRK:MEWNX:IT&\_trksid=p3984.m1439.l2649

I can’t tell if it’s protected or not?

Jim

Hi,

Oops. According to this:

So I guess they’re not protected.

So is that 14500 is “toast”?

Jim

Alex,

These were new batteries, so I’m communicating with the seller, to see what he wants to do.

Thanks,
Jim

ohaya

I have some of these from an Efest dealer china - they are not protected as far as i can make out, be safe either dispose of it safely or see if you can obtain a replacement or refund as you say they are new.

bones,

Agreed. I’m working with the seller.

My preference would be to try to get a replacement, and hopefully it’ll work out, because, earlier, I got another bad battery (not an Efest, but a blue TR-18500) that he had already previously agreed to ship a replacement for.

Later, and thanks all,
Jim

P.S. Which Efest did you get, and how’d they work out? I kind of took a chance on these, but it was a U.S. seller, so I figured it’d be ok…

sure ask for a replacement, but you can still try to use the bad one

I use an old, dumb 270mA AA charger to revive, never had problem. But don’t mix it with other cells, only use it alone. It might suffer low capacity and high self discharge.

Hi,

Are you saying to put the 14500 battery in an NIMH charger to revive it?

Jim

Just play safe and trash it!

Milan has never had any problems, but that doesn't mean that you wouldn't have.

It's just a couple of dollars, really low price to pay to stay safe..

Hi,

Understood, but I really am curious, as I’ve seen posts at various places about doing that (putting the “dead” battery in an NIMH charger). I do have an NIMH charger, but it only charges pairs of batteries, so I could do that anyway.

Thanks,
Jim

no, its really not worth the risk, cell failure is going to vent some really nasty chemicals.

hopefully the seller will sort it out but its really not worth the risk to try and use that cell.

Thanks. The seller is working with me. I’m shipping the bad Efest 14500 plus a Trustfire (blue) 18500 that wouldn’t carry a load back to him, and he said that he’d replace both with some non-IMR protected batteries, but I kind of had the feeling that he’s not 100% convinced that both batteries are bad :(.

Hopefully, he’ll come through, but at this point, I just have to wait and see.

Jim

Panasonic and Sony put their limits considerable lower:

For Sony it is 1.5 volt.

For Panasonic it is somewhere below 2.3 volt.

yes, the one I have tops the voltage to about 3,6V. The voltage rises quickly.
But I haven’t tried it with those chargers that charge pair only.
Basically any slow charger can be used. It only takes couple seconds to reach 3 volts and than it doesn’t matter much. Just don’t insert it in those 1amp chargers and such.

to sum it up:
I wouldn’t bother reviving some old recycled cell reading so low. But if its supposed to be a new cell, chances are it has degraded just a little and will work fine, just not 100%.

Milan,

I may try that at some later point, but for this one, I’m returning it to the seller for a replacement.

Thanks,
Jim

Efest IMR 14500 version B 1 flat top cells - http://www.efestpower.com/Product/0237485527.html

Most Sony cells are a different chemistry… for lithium-cobalt cells the chemistry can become unstable if they are discharged too far. If recharged they can spontaneously combust at any time in the future.

The Sony "Lithium Ion Rechargeable Batteries Technical Handbook" does include Lithium cobalt batteries.

They do specify that you must not discharge below 2.5 volt (or 3 volt), but the charger is allowed to work from 1.5 volt at reduced current.