So, when I first got my Thunderbolt, apparently the eHRPD functionality was down in the Verizon network. Once I found that out, I turned it off so that I could pick up 4G better since it was causing issues with that. Recently, I decided to turn eHRPD back on. That was on Wednesday. That same evening, at some point I think the phone started trying really hard to reach a signal, and I think it must have been rapidly switching between looking for 3G or 4G. The phone was overheating and by the time I noticed (I was taking an exam at the time) the battery level plummeted. The same thing happened on Sunday as well; I was at a baseball game and when I went for my phone after riding the metro home the phone was really hot and at a low level. In general, it seems having that option turned on reduces battery life significantly, as I consistently got 58 hours (according to the JuicePlotter app) per full charge before switching eHRPD back on (after which it dropped to 28 hours). To recap, this is how to disable eHRPD: ##778# hit dial, edit mode, password is 000000, modem settings, Rev. A, change to enabled, instead of eHRPD, hit menu, commit changes, reboot Also, I do have the latest JuiceDefender beta installed, but that has been on my phone for a month with no major issues.