Motorola Droid 3

have you turned off global roaming? For me, with global roaming off, I can get close to 18 hours of moderate use, more than 12 of average use, and close to 8 of pretty heavy data use.

Menu > settings > Wireless & Network > Mobile Network Settings > Network Mode. Set to CDMA only. Unless you do a lot of global roaming that should fix the problem. I suspect that it has something to do with the fact that the phone can't lock onto the US GSM bands, so it spends a lot of time (and battery) searching for a GSM network that isn't there (similar to the battery problems of people with LTE phones in non-LTE areas)