I do usually have CDMAonly on my hero as i only need it for few calls google voice sipgate and texting. im in a rural area. And just use it for wifi cause theres no service. I keep phone on airplane mode and keep wifi alive (always on setting) and background/sync off. And timeout 15secs also PRL is set on "unknown" now. So far phones been on 2 days 3 hrs 19mins and at 46% battery. Is the phone ok in unknown mode? i think it switched there when i was out today where there was service. Im on Ntelos/Frawg prepaid