My last phone I had before my Charge was the G1. And I was using the previous charger from my old Sidekick III with it because they were the same size. I then noticed my phone started dying really quickly, and soon it came to the point where it would only work while it was plugged in. I took it to a T-mobile store and they said that the different charger had caused my battery to "swell" up. And sure enough when i looked at it and compared it to a new one, it was impressively bigger. I think he said it needs to be the same output voltage thats printed on the charger. Not necessarily the watts, but the voltage. It will say something like OUTPUT: 5V=1A. Those are the numbers that need to be identical with chargers. (Correct me if I'm wrong)
