Trustfire 14500 crappy discharge?

[sparkysko]

Doing some testing on a 6 month old trustfire 14500. Probably charged it 10 times in its life, and was using it in a Nitecore d10 until the cutoff.

If I fully charge it, and then drain it at 0.7 amp rate, I can only suck 100mAh out of it before I hit 3 volts. If I drop the rate down to 0.3 amps, I can only draw about 2-300 mAh before it hits 3 volts.

Is this about par for the course? Suprisingly, when I go to recharge them at 0.7 amps, it only takes a few seconds to get them back up to 4.2 volts. This is the behavior I'd expect from a bad cell for lipo, but I'm not too familiar with li-ion. This is my only battery until I get my next order in.

 

[VidPro]

you didnt say how long you have had the battery for.

every 14500 that i have piddled with (sometimes known as testing) hasnt lasted a long TIME. like maby a year year and a half. i also dont know how long it sat on the shelf before i bought them.

after enough time, they act about like your saying.

 

[Black Rose]

Doing some testing on a 6 month old trustfire 14500.

you didnt say how long you have had the battery for.

 

[VidPro]

well then deep discharge it to 2.5v , SAFELY recharge it using a 50-50% fast pulse, then discharge it again testing it, , , then recycle it and get a new one. :mecry:

in the mean time i will go get some reading glasses.

 

[sparkysko]

Eh, only pulled maybe 200mAh out at 2.5 volts. I tried draining it until the protection cutoff kicked in, which wasn't that far after the 2.5 volts. As soon as I'd reactivate the cell, it'd bounce back to 3.7 volts resting voltage, so I figure it's just a crap cell.

Hit it with my 500,000 btu weed burner. *pop* problem solved.

Now I get to figure out if it crapped out from the Trustfire charger or from continuously draining it until the cutoff.

 

[Black Rose]

Now I get to figure out if it crapped out from the Trustfire charger or from continuously draining it until the cutoff.

Could be a bit of both, but I suspect the latter statement is what killed it.

Regularly draining a cell until the protection circuit kicks in is bad for a cell.
Protection circuits are a last resort catch. Once a Li-ion cells hits 3.6 volts, put it on the charger.