AW C-cell problem.........stumped

[pete7226]

Ok, Ive been using the original AW c-cells in my light to power a wa1111 bulb, this setup has worked flawlessly for about 1 1/2 years as my primary duty light, probably have 150ish cycles on the batteries on a wf139 charger. recently I noticed that after about 50 seconds the light turns off. The batts read 3.88v. when I turn it back on, it turns off again about 20 seconds later, turn it off and on again, 15 seconds later it turns off again. The batteries cant be that depleted can they? they still read over 3.8 volts, and when I charge them they're almost usually around 4.17-4.19. I'm stumped. Up until now theyve worked flawlesly, any ideas, suggestions?

 

[Black Rose]

This is just a guess, but it's possible that running that lamp has shortened the life of the cell.

If it goes from 4.17v to 3.88v after only 50 seconds, your cell seems to be in bad shape.

If the cell was reading 0.00, then it would be a problem with the protection circuit (if it has one).

 

[65535]

Protection circuit kicking in? Try taking a voltage reading under load, that should answer the important question of if the cell is good or bad.

Unless you haven't been charging the cells properly and maintaining them they should last far longer than 150 cycles.

 

[pete7226]

How do I test under load? I have a radio shack multimeter.

 

[Conte]

Have you been deep cycling the batterys ? Like running them dead each time ? Doing this with the load of a 1111 could shorten the life of a Lion cell. They've got some age on them also. I've had batteries fail on me after about that duration of heavy load deep cycle use.

Perhaps your batterys are just done.

Have you tried asking Mr.AW himself about this issue ?

Testing under load is a straight forward concept, to hook up the meter and the bulb at the same time, to get a voltage reading while its running. Just hooking up such a test might be tricky.

You can try taking the head off your mag, and pulling the bulb up just enough to that you can touch your probes to the bulb pins. It's tricky mostly cause you have to look at the bulb while its running. Suggest you wear a good pair of sunglasses while doing this.

Now, this will give you a reading of both batterys at the same time, but will still give you a good idea of how much they are sagging under load. You can always divide your reading by 2.

It's easy for a dead battery to still read 3.8 volts while idle. But under load, the voltage will sag below cut off.

 

[pete7226]

Ive probably run them until dead maybe 3-4 times, Ill try to test under load, it might just be time for new batts, which means going back to 18650 2600 mah as the host I have will not accommodate AW's new C cells. ill try it and see, thanks for the info.

 

[larryk]

I have a similar problem with one of my AW C cells. The 2 cells have been sitting in my light unused for about 10 months. Today I needed 1 cell for a different light. 1 cell works and the other does not. The bad cell reads 3.82 volts with no apparent amperage. My Ultrafire charger does not recognize it. I used my Hobby grade charger set for Li-Ion and that charger states over voltage. I'm also stumped. I wonder if the protection circuit is malfunctioning.

 

[Conte]

I've had protection circuits glitch out on me.

This one set of batteries I have, when I run them in my Mag11, they won't start up at first, I have to quickly turn the power switch on and off exactly 3 times, then it kicks in.

Again, have you consulted AW himself ? No one will know more about this then him. Perhaps there is a known problem that has come up with a few of his cells, and you just need the protection circuit repaired or replaced.

Most people would of contacted him first.

If it was me, and I was ready to write the cells off, I'd remove the protection circuit. Then try the battery again. Be careful though.

If the battery is still misbehaving, I'd at lease keep the circuit, might come in handy one day.

PS: AW's new C-Cells are lower Capacity then the 18650's anyway.