Protected 18650 went Dead !! What...

[tripplec]

Well a early protected battery I'd bough for flashlights was turned on in a recent power outage. Today my wife brought it to me. Dead, ok I though yeah I'll just pop it in the charger. My charge said Err, hmmm after a few tries I got my meter out and its 0VDC. What, I always thought the protection cap would not allow a over discharge let alone to Zero. Well I am going to toss it.

I believe they're Sanyo 2200mAH from very long memory. I just thought I'd post it as it shouldn't happen in my opinion and most. All my batteries are protected.

 

[john61ct]

The protection mechanism may be isolating the internals, preventing an accurate voltage reading

 

[badtziscool]

If the protection is tripped then it should read 0v since it's an open circuit. I don't recall how to reset the protection though. For some reason I recall something about putting it in the charger backwards for a second and then take it out. But PLEASE don't quote me on this. Best if you can look on the battery's manufacturer site for information.

 

[badtziscool]

https://batterybro.com/blogs/18650-...-battery-safety-101-anatomy-ptc-vs-pcb-vs-cidJust because I don't want to give any wrong ideas when it comes to Li-ion batteries, here's an article about the various protections of Li-ion cells.

seems like if you specifically know this cell has a pcb protection circuitry then it can be reset. If it has any of the other protection methods then the cell should be considered gone and be disposed of.

 

[jeff51]

Usually with a protected cell has the pcb tripped it can be woken up by putting it in parallel with a charged battery.
To be safe some recommend using a resister to limit current.
Even a battery at 3.6v should revive it.
Many chargers have the ability to wake up a tripped protected cell.
All the Best,
Jeff
only needs a brief connection. Don't leave it connected or the charged cell will dump into the discharged cell.

 

[ChrisGarrett]

Take a known good battery, put it nose to nose with the tripped battery and quickly short the two negative ends with a wire/paperclip and reset it that way.

It's 'science,' but it's not 'rocket science.'

Chis

 

[tripplec]

Its > 100% protected, all I ever buy.

I tried it in and out of the MiBoxer C4-12 and no go. I do have another charger I haven't used since getting the MiBoxer. I could try it and see.

I don't see why they cannot be normally recharge when they hit the protected limit. As that would be the normal scenario when using them rather than unprotected cells which you'd most likely over discharge. We all don't expect to do some inverse wizardry to initialize the cap after. That would be a huge downside of the protected cap when we hit the stop limit. IMO

I have yet to read the link provided on BATTERYBRO. I'll do that now and see. I have quite a number of spare new ones but posted only be cause I could not recharge it.

EDIT: I read the link provided and clearly its not reset on its own as it should have.

 

[tripplec]

Well it didn't work. Gave up however, I left it in the C4-12 charger and went about my business. An hour or so passed and I came back and notice the display was active without the Err and it was charging. Looks like its coming back. I'll see what the mAH input is at the end.

 

[NiOOH]

There are chargers that can reactivate tripped protection circuits. If the charger managed to start charging it, it will be OK and back in service.

 

[tripplec]

OK, I don't know exactly where it started but was in the 3VDC range somewhere when I noticed it. its up to 3.91V now as I type and it showed 40 min charging time.

 

[NiOOH]

That should be it.
I noticed recently that my RC3000 does a similar thing (with a proper indication though). I was checking the capacity of some new cells that I've bought, discharging down to 2.5 Volts. One hour after the end of the discharge cycle the voltage has bounced back to something like 2.90 V, i.e. below 3 Volts. When I switched to a charge program (I wasn't using cycle program), the charger applied only 150 mA charging current for couple of minutes, until the voltage reached 3.0 V and then ramped-up to the programmed 1.5 A charge current.
Perhaps, yours is doing the same thing.

 

[tripplec]

I'd be guessing but something happened behind the scene for me. The charger is also a bit odd. I don't like the auto current selection it uses as it usually very low for 18650 cells. I try and toggle it up to 1.0A most of the time. But doesn't always take or hold it. It gone down to .4A and I cannot make it go up for some reason. Although 95% charged so its not a bit deal. I don't think I'd by another charger like this with an Auto mode that truly cannot be over rode. This is certainly the master and doesn't obey my wishes!!

 

[tripplec]

Well it just finished charging. 2545 mAh on the display. More than the spec but it went way way down and likely accounts for the additional mA.
Done I guess now.

Why are attachments not allowed!!! I notice at the bottom a restriction. No other pasting method appears supported here.