At 12:44 PM 10/18/2004, Peter Johansson wrote:

>Dave VanHorn writes:
>
> > Check the current drawn, NIMH don't like large discharge rates.
> > Or long term unterminated charge either..
> > This is one application where Nicads may yet be the best thing.
>
>Can you explain this in a little more detail?  I was always under the
>impression that one of the big advantages of NiMHs was their high
>current capacity.  Are NiCads substantially better than NiMHs in this
>department?

NIMH have large capacity, but don't like to deliver large currents.
Nicad has smaller capacity, but is better at delivering large currents.

>I'm not sure I understand "long term unterminated charge" either.

Wall-wart charger, "18 hours" left on forever sort of thing.


>  I
>have noticed that my NiMHs self-discharge completely after about a
>month or two, and after this has happened, they don't hold a good
>charge again until after a few charge/discharge cycles.

New NIMH cells also have to be cycled to get full capacity, but cycling 
them without a specific reason, is just spending life.

>  However, if
>kept on a proper float charge, they do seem to maintain full capacity.
>Or, were you simply referring to the fact that a non-intelligent
>charger is bad for the batteries?

That too.

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