Bah! My "trustfire" Li-ion 123 was not "trustworthy"

[AlexGT]

What gives? It went dead on the FIRST charge?

Just recieved it from DX its the model DX8683, started voltage at 4.02v out of the wrapper, started charging at 400mah and when it hit 4.25v I disconnected and put it in my Jet II Pro, press the switch and nothing!

I pulled it out and tested it with the charger's voltmeter and it shows 0.00v! I'm like WTF! then I test the other 3 TF's that came with my order and had just charged fine up to 4.23v and all read 4.15-4.19v and work just fine in the JB light.

I used a needle to pick right thru the protective envelope and test voltage, and sure enough the dead battery reads 4.11v, so I think the PCB went kaput! How can I revive it? or just throw it away or make fun experiments with it?

Thanks in advance for your suggestions

AlexGT

 

[mdocod]

The premature absolute failure on the cheaper cells is *almost* always the PCB and not the cell itself... this is a commonly reported problem.

It does sound like your charger is using an improper charge algorithm, holding CC to above 4.20V is not necessarily good for the cell. Some PCBs have a higher tendency to fail when the cell of overcharged.

The PCBs in nicer cells are designed to tolerate up to 12V+ so they can handle mistakes by correctly shutting down the cell until the problem is solved, at which point they will trip back to normal operation.

 

[Mr Happy]

If the protection circuit thinks the cell is being charged to too high a voltage, it will shut down to prevent a venting with flame incident. Just what it is designed to do.

The question is whether it will automatically reset itself later on, or if it will shut down permanently...

If the cell arrived with a voltage of 4.02, why not use it first to discharge it before recharging? 4.02 V says it already had a pretty good charge on it.

 

[marschw]

What charger were you using?

 

[mdocod]

good question marschw! I'll second that question. May help identify a problem.

 

[AlexGT]

The charger is a MRC Superbrain 969 charger, I use it all the time to charge, protected Li-ion, nimh, nicad, and SLA. I wanted to top off the cell to do a runtime test with it and get to know it better.

I think it was just a fluke that the battery went dead, the remaining 3 are working perfect, I think i read somewhere long time ago to revive a PCb to give it a 6v jolt for 1 or 2 seconds. Anyone heard of this?



AlexGT

 

[coppertrail]

Consider better cells

I purchased (4) SureFire 18650 Protected cells about 9 Mo. ago. After only 2 charges, I lost 2 of the 4 cells. Since then, I've gone with AW's Li-Ion 18650s and a Pila IBC charger.