In the last week of July a number of T-Mobile subscribers began observing that the battery life of their HTC handsets had fallen away dramatically. Both my wife and I have the G2 (aka HTC Desire Z) and have found that typical battery life has dropped from 8-10 hours to less than 4 hours on a charge.
In fact, I noticed that the back cover of my G2 was warm to the touch even as the phone was sitting idle all morning. Even in a completely idle state the phone was drawing enough current to make the battery warm.
There’s a long thread about this issue in the T-Mobile support forums. Over the past few days others have noted the issue in various places, including; Phone Arena, T-MoNews & Phandroid.
While that thread includes a lot of conjecture the reality of the matter seems to be simple enough. HTC handsets on their HSPA+ network are reacting poorly to recent upgrades to the network that were principally intended to improve network throughput.
This morning I finally broke down and called T-Mobile customer service about the issue. Whereas until today T-Mobile customer service was not acknowledging the problem, this morning their tier 2 support group are acknowledging the issue. This morning they tell me that matter has been reported, although the details are slow to make it to the front line CSRs.
According to T-Mobile they have notified HTC who are working on an OTA firmware release that should resolve the issue. That firmware release is not the Gingerbread release of the OS that began OTA distribution last week. It will be an entirely separate release.
Until this new release is available anyone with a T-Mobile issued HTC handset can achieve nominal battery life by simply forcing the phone to use the companies 2G/Edge network. Turning off the HSPA+ radio turns off the source of the power draw. I have confirmed this fact with our two phones.
You can leave the Wifi radio on, and so have fast access to data while in a wifi zone, but otherwise rely upon Edge for voice and much slower data.
Update: Here’s a related thread from XDA Developers Forum.