question for the professor.

GoldenMotor.com

deacon

minor bike philosopher
Jan 15, 2008
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north carolina
So it looks like the nimh batteries i bought have a less than 1c or something. My patience is about gone. So what I'm wondering now is. Can they be used in conjunction with the SLA batteries I already have.

I think batteries like water finds it's own level. In other words a battey pack draws from each battery to reach the same level of volts and amps for each cell in the pack.

I know a bad cell brings the pack down and you have to isolate it to find the bad on e. But what would happen if I just added the NIMH pack parallel with a sla pack.

The sla would allow the motor to draw the 30 amps it needs but would the nimh replace them or just burn up trying to keep up. Just a thought.
 

cannonball2

Well-Known Member
Oct 28, 2010
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Colonial Coast USA.
When nimhs came on the RC scene we thought they were the next best thing coming. We concluded rather quickly they were in most ways other than size/weight inferior to the old nicads we were used too. They had to be cycled several times when new to reach close to their rated ahs. They required careful charging, and cell failure was common ruining a pack. Maybe this was only with the earlier batteries, but we soon began searching for the disappearing nicads. Also there are different types of nimhs. The common rechargeables are of a low C rating. Im no expert on these batteries but my experience with them ended my use of them. I know this is not exactly pertainent to your question but maybe it gives you a little info. It would seem the old batteries like Pb and NiCad are the most forgiving of misuse. I like Lipos and have had no bad experiences with them, but am going with SLAs initially.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
221
63
Colonial Coast USA.
Thinking on the nimh/SLA combo, I think the nimhs would deplete pretty quickly trying to keep up with the amperage(Cs) of the SLAs. At that point(my thoughts anyway) they might try to pull the SLAs when the amperage load eased. A current flow thing. Don't know about overall reduction of output I guess the nimhs act as a storage bank, but my logic makes me think under lighter loading there could possibly be a 2way flow from the SLAs charging the nimhs. If the nimhs had an equal or slightly better C rating should work fine, I just doubt the nimhs are up to it.
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
0
north carolina
Believe it or not it may not be necessary after all. I finally took someones advice and soldered the connections between individual cell and eureka it works just as it should. I have to get credit for dumb rear of the year.

I also charged them 3 amps at a time for five hours till they got just a little warm then stop. The pick up was excellent and i have really great hill climbing. I have one 36hour pack i used today and I have another 18hrs to include in the final load before I test the range on the pack.,

Thanks for all the help.