> I am familiar with charger schematics for single cells, but... I cannot
> find any information on charging
> multiple cells. (ie 4x AA cells 1600mAhr, e.g. shall I have these cells
all
> independently
> charged or is it reasonably safe to series them all up??)

The commercial plug straight into the wall charges series the cells to
provide 2 separate charges of 2xAA or 2xAAA.. or 2 separate 9v charges. I
think theres some quite detailed info about charging if you visit the
battery manufacturesers site-- I have found rayovac t be quite informative.
If your charger is a constant current charger then theres no reason why
cells in series wont charge properly.

> Planning on doing a PIC -based charger (to control charge time, LED mode
> display to user, PWM operation, and other) that pulse charges using PWM
> waveform for say 3seconds then shorts all batteries for 100msec, cycling.
> Apparently this charging scheme is the one to go for, for long life of
your
> batteries to reduce those "dendrites"....

Am thinking of doing the same thing for an alkaline battery 'charger' /
reconditioner- relies heavily on PWM- albeit very low frequency PWM. Be
interested to hear if you get any good results.

> Anyone got any help/tips/neat circuit ideas?

Main hint from experience : for NiCDs.. make sure you discharge them fully
before starting to charge them or your batteries will not last very long. I
think the memmory effect is well documented but underestimated by most
peple- but on the other hand-- NiMh batteries are much nice to deal with
then NICd betteries-- ( & more envirmonmentally friendly as well !)

> Thanks,
> Bernard Wood
> New Zealand

Jon Baker
Birmingham
England.

Ex Australlian resisent, Ex, American Resident :)

Jon Baker
jon@jb707017@hotmail.com

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