For use with a reserve battery couplable to a charging circuit capable of providing a charging current to the reserve battery, a mode selection circuit and a method of operation thereof. The mode selection circuit includes, in one embodiment, (1) a signal generator that generates a signal based on a...http://www.google.de/patents/US6037747?utm_source=gb-gplus-sharePatent US6037747 - Mode selection circuit for a battery and method of operation thereof
