On Feb 19, 2008 12:29 PM, Dr Skip wrote: > You could use FETs or even low power relays. Don't do any fancy switching, > since you can overlap the batteries for a small instant for the switching. That's not as easy as you think, there's a body diode that will allow both batteries to feed to each other. google batfet. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist