Quoting Dwayne Reid : > At 10:34 AM 5/24/2010, David wrote: >> I have a small battery (a Varta 3.6v) and a solar cell (6V 15mA max >> output). I intend to use the solar cell to keep the battery topped up. > > I can tell you how I handle a similar (but much larger) system: > > I monitor the battery voltage before and after the series diode on > the solar array input. I use a large FET to shunt (short) the output > of the solar panel when I don't want to accept any more charge. > .. > Hope this helps! This is really useful information, thanks. It is good to see that the principles scale upwards as well. David -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist