There's been a lot of problems, questions, and confusion about the charging the batteries of the Revo. Problems have included the unit shutting off while sounding the alarm, and the batteries continuing to charge at the high rate (red light on) over 100%. I'm not going to go into full details here as they've been discussed for weeks on end over at sites like Revoworld. Kevin Millican has put up a website that details about how to charge the Revo to give the batteries a long useful life before you have to have the batteries changed. As well, this site has a program called ChaDis ONLY for Revos that help you keep track of battery usage over time, which let's you know how many hours of use you have left, and the equivalent number of days of the unit being left inactive remains in the batteries (note: this program has to keep running in the background to work). Kevin Millican's site can be found here. [ Top of page ]