Robert Swirsky-Warner wrote:
>
> Folks:
>
> I've been considering designs for a PIC based  Gel-Cell charger (with
> photovoltaic
> power source.) I've been looking at the Maxim chips, but can't help to think
> that someone's done this before, and that with a PIC and a few A/D channels
> I can monitor voltage, temperature, battery charge (and run my application
> from the same PIC.)
>
> I searched the usual places, and turned up nothing. Anyone know of a simple
> design for a PIC-based Gel-Cell charger? I thought that PIC was a major
> supplier of chips for "smart" battery packs, but the app notes on their
> site seem like overkill for keeping a gel cell happy.

If using solar cells, try a web seach for MPPT
regulator design. This is a variable current
system that adjusts current to get the max power
from solar cell at any light condition. I invented
it at 12 years old and thought "it'll never catch
on"... Years later someone else thought of it
and it became big money industry.

As far as the gell cell goes, the simplest system
is to use a voltage regulator to limit max charging
voltage. If you never charge them over a set voltage
they last for many years.
-Roman

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.