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recloosetrav
08-24-2009, 10:58 PM
Hey guys. I have a question that maybe someone could answer. I had fully charged a couple 3300 mah nimh batteries and realized right when I was goin to run my boat that the flex cable was frayed. At the end and I had to stop right there. Well anyway if I have let the batteries set for a couple weeks at full charge is that going to hurt the cells?
SweetAccord
08-28-2009, 01:57 AM
You can't hurt NiMH batteries if they are fully charged unless they have been over charged, meaning they were allowed to get hot for a long period of time.
Fluid
08-28-2009, 07:40 AM
NiMH cells should be stored discharged at between 0.9 to 1 volt per cell for long term storage. I doubt that two weeks sitting at full charge will bother them, however you will need to re-charge them.



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sjslhill
08-28-2009, 09:01 AM
Hum, I don't really agree with Jay on this one......Nicads should be stored that way. NIMH should be stored charged in my opinion on long term. Cycled once or twice before running again.
SweetAccord
08-30-2009, 07:44 PM
Hum, I don't really agree with Jay on this one......Nicads should be stored that way. NIMH should be stored charged in my opinion on long term. Cycled once or twice before running again.

Funny I agree with you. From personal experience and from numerous articles, and sites, NiCads and NiMhs have a slow discharge rate of their own, (Nimhs not as fast but will) I don't recall the values etc. When you discharge them it won't help them for storage as once again they will eventually discharge on their own slowly. To allow them to sit in a stored state longer fully charging them allows them to not reach their self discharge state as fast. When you need to use again, cycle and fully charge again. On the first cycle do a slow charge to allow all the cells to balance equally so they may all charge to an equal end total charge. Discharge, then on the second charge, charge at a regular C rating of 3.3 A. I have always done this and even the cheapest to high quality packs have lasted for me.

~Peace.
sjslhill
08-30-2009, 07:51 PM
My experience is that they will lose capacity forever if they sit too long discharged. Jay was running his every month, year round.
SweetAccord
08-30-2009, 08:00 PM
My experience is that they will lose capacity forever if they sit too long discharged. Jay was running his every month, year round.

Correct.