On Fri, 29 Dec 2006 11:46:22 -0800, Mike Fields wrote:
> You also want to avoid mixing cells of different capacities together
> since you can get the situation (depending on how they are being
> used and what the cut-off voltage is the gadget) where one cell
> will get reversed. That is NOT a good thing. It is also the weak
> link -- if you have a 4 cell application, 3 - 3000 mah cells and
> a 1500 mah cell in series, you are basically limited to the 1500
> mah cell.
That's generally true, but other than reducing the usable
capacity, it's probably not too much of a battery killer in digital
cameras, since all of the ones I've seen would probably power off
long before the first cell approached a reverse charge. Analog
devices are the real killers, as they'll frequently continue drawing
current even when the total available voltage is as low as 1 volt.
To reinforce what you're saying though, if I detect that one
rechargeable cell out of four has gone bad, I'll *never* replace it.
All four get replaced, with the remaining 3 decent cells being used
to power devices that use only 1 or 2 or 3 AA cells. I have an mp3
player that normally gets 50 hours from a AA cell. If I can use a
bad NiMH cell in it that only is good for 30 hours per charge, I
don't consider that to be a real hardship.