>
>
> Harold Hallikainen wrote:
>> watches the battery voltage. If it stops rising for a few minutes, I
>> assume the battery is charged and turn off the charger.
>
>> is "zero delta V charge termination."
>
> What percentage 'full' are they at that point? Have you had a chance to
> test
> their capacity vs rated capacity after several cycles like that?
>
> -Skip
>

No, I haven't done tests on it, but it seems to work. The zero delta V
seems to be the suggested method for NiMH. NiCd often uses negative delta
V, but apparently NiMH doesn't go very negative.

There seems to be a lot of nice single chip lithium ion chargers (I've
used some LTC and Maxim ones), but for NiMH, they generally require
external transistors and external charge termination detection. That's why
I'm going external on the latest project. The whole charger is not much
more than a switching wall wart.

Harold


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