Draining C123 Batteries

[Flying Turtle]

As a new owner of an Arc LSL I will soon (must wait til Christmas) have some run-down batteries. Assuming there is still some usable juice left, what's a good way to get it out? Could I jury-rig my Infinity or Arc AA to use them and not be subjecting the lights to too much voltage? Sorry if this topic has already been discussed ad nauseum.

 

[Steelwolf]

This topic has been discussed quite a fair bit and you may do well to check out the Milky Candle from CPFer MilkySpit. A good circuit to extract the remaining juice would be with a joule thief discussed in this thread, otherwise known as the SatCure circuit. And check out the modified SatCure circuit. A search in the archives should turn it up.

I believe that when the Arc switches to moon mode, there is still quite a fair bit of juice in there. I have one CR123 from my Arc-LS. The open circuit voltage is about 2.8V but it is only as bright as an Arc-AAA.

Actually, something may be wrong with my Arc-AAA, so I can't compare for sure. The beam is looking a little green.

 

[RussH]

I have been considering these things as dead at 2.8v. Sometimes they are, like after being in my XT. But they come back up to 2.8v after sitting around. They don't have any current capacity, however. IIRC, the last set fresh from my XT were at 2.4v upon removal, I'm not sure what I did with them. But I've had dead batteries at 2.8v and not so dead batteries at 2.7999v.