My charger was bad out of the box, but with low voltage. Before I knew it, the charging circuit was damaged, and can no longer tell how much charge it has, or warn me that it is drawing down. It just says it is full all the time until it suddenly blinks off. I flashed it to Willow's v.1.2 over the weekend, and while the unit works much better all around, the problem with the charging sensor remains. I got a replacement at Walmart that is a multi-volt unit also. I am paranoid though, that I will bump the switch, and accidentally fry something else!