I updated to Froyo and all seemed well the first night. The next day I was killing the battery in 6-7 hours and hardly touching it. Here is what I did.
- Turned off Google Talk (I want this back, but if this is the killer I will do without it)
- Uninstalled/Reinstalled Google Voice
- Uninstalled Advanced Task Killer (people are emphatic that Android does not need this and that people are just trained by Windows to close everything)
- Removed all data consuming widgets
- Went to Settings > Applications > Running Services and stopped all data widget services
- Eventually put back all the widgets
- Turned off background data for an hour and turned it back on
- Downloaded “Network” application. Changed drop-down to GSM auto (prl). Changed back to CDMA auto (prl).
- Calibrated battery (Charged overnight, Unplugged, Turned off (hold down the power button and shut down), Plugged back in (turns orange and then green in about 30 seconds), Unplug, wait for green light to turn off, plug back in and wait until green, repeat about 10 times.
I burn about 6-8% per hour now (back to where I was on Eclair). I played around a bit and turned Gtalk back on. I was back to 12-15% per hour burn rates. It is clear that Gtalk is killing my battery after the Froyo update (It did not on Eclair), unless there is some burn-in effect that I need to let happen.