My Motorola Atrix 4G came with 2.2 and later Moto upgraded it to 2.3. Under 2.2 I had no battery issues, but under 2.3 it has been a nightmare! It will show 90% charged one minute then the next minute it warns me that I'm below 20%. If I reboot it it might go back up to 90% again, or something else. It is definitely flaky under 2.3 and I must constantly charge it every night just to make sure it stays charged, and even then it occasionally flips out and suddenly drops to less than 20%. Is it Moto or is it Android? My guess is it is Android because those idiots have shown time and again that they don't know how to produce a stable and decent OS!