Ok so I’m playing with a Crelant V31A that just came in the mail.Went and dug out some of my 16340 and find one of my E-fest cells below .5 volts! :~ I’m sure I didn’t store it that way so I guess it self-dischared .The funny thing is the cell of the same age next to it and the other brands were all between 4.13-4.17 volts.I did place it in my X-tar WPS2 set to .25 amps for a few min.The lights flashed red but it did bring the voltage up to 1.5 volts.I would never try and recover a lithium cobalt cell, but I am under the impression the IMR’s are safer.Would it be safe to try and charge this thing or just should I just toss it?I wouldn’t mind playing with it to see how it reacts but not if it could be dangerous.
Oops, I just killed the other one!Aparently the V31a dosen’t have a love voltage cut off!Guess I’ll have to stick to protected cells with it.
That was pretty quick? Are you sure there isnt something else going on? Seems awfully quick for a cell with reasonable charge (>4.1v) to be under voltage, your posts are only 5 minutes apart.
Stupid laptop just wiped my entire response.Anyways I had been playing with, I mean testing the light for a while before I noticed the dead cell.So it wasn’t really all that quick.(I think I had a similar conversation with my wife one night 
)The good cell I drew down to 1.5 came up quickly to 2.3 volts resting so I put it in the charger and it is charging normally.Anyways, does anyone know if it is safe to try and charge the bad cell?
Are you sure it’s a WPS2? That charger does not seem to exist. Anyway what ever charger… it is behaving like other chargers that are designed to automatically detect voltage and type of battery. IE:
lithium-Ion or NI-MH. The charger thinks that you have inserted a NI-MH so it only charged to 1.5 volts.
I have ran into this with laptop pulls, just remove the battery and reinsert it to continue charging. The Li-MN cells are considered safer and less detrimental to over discharge.
However please be present to observe the cell while charging and check it several times after the charge cycle to confirm that it is holding the charge. Compare it to the other cells. If all is good then your cell will be fine.
If your charger is a WP2S then this may be what has occurred. Straight from XTAR’s description:
*Three-phase charging method plus 0V activation
*Repair over discharged batteries
That usually just means it can reset the protection circuit if it's been tripped because the cell hit the low voltage cutoff point (the cell voltage is actually 2.5-2.8v, just internally disconnected from the outside world), not a cell that's actually discharged down that low.
I agree with your statement regarding a LI_ION.
Being an Li-MN cell it will likely not have a protection circuit so how would the charger go about determining whether it was a good or bad cell. Since a Li-MN cell was inserted with .5 volts and the WP2S does not apparently have circuitry designed for NI-MH and a built in safety feature of 1.5 volt max.
Upon implementation of the protection reset feature the charger did not detect a voltage increase of up to 2.5 to 2.8 volts why would it stop charging at exactly 1.5 volts?
Again I’m not disagreeing with you comfychair, this is me learning.
I didn't interpret the OP as saying the charger shut off at 1.5v, only that that's what it was at when he pulled it out to check if it was safe to continue charging.
I just meant that when you see that 'repair over-discharged batteries' feature on a charger, they're talking about resetting the tripped protection circuit and not actually anything to do with 'fixing' a cell that's discharged down to very low voltage.
Ok, I thought that it might also include the ability to charge a battery that has been discharged below a certain threshold. I have had chargers that will refuse to charge a Li-MN or LI-ION battery below a setpoint threshold. I know this is a safety feature, and I know not to discharge batteries that low, sometimes the wife just does not place much importance on telling me when her batteries are dead. Still used to alkaline’s I think.
The Crelant V31A has a buck/boost driver that has no problem pulling juice from a li-ion until it reaches 0.7-0.8V. Be very careful when using unprotected cells, and it can easily kill them.
But I do recall they have a low voltage flash when it drops below 2.8V?
The charger is a WP2s, typo.I’m gonna put the cell in the charger for a short time this morning and see what happens.I just don’t want to have a venting event.Ryonsoh3, I never got any warning that the cell voltage was that low from the V31a.It just got really dim and wouldn’t switch modes.When I checked the voltage on the good cell it had been drawn down to 1.5 volts!I guess I’ll have to order some more protected 16340’s.(I only have one AW, all my other 16340’s are IMR’s.)