What's causing battery drainage by "Google Services" while packet data is switched on in a 3G dead zone?
It looks like your phone tries to build a 3g connection only if packet data is enabled. After all, 2g is just fine for voice and texts. But unsuccessfully trying to create a connection when there is no network costs a lot of power.

In my experience, phones normally cope just fine with that. My theory is that the 2G signal normally contains some sort of flag that indicates whether there is also a 3G signal. The 2G repeater would incorrectly send this flag -- possibly because the tower it gets its signal from sends it too. Thus your phone wastes energy trying to connect to a signal that only exists somewhere else.

If you cannot (or don't want to) replace the repeater by a more sophisticated model, you should turn off 3G altogether while in your office. GSM phones have a setting in Wireless &amp; networks -> Mobile networks -> Network Mode that lets you switch between WDCMA (3G) and GSM (2G). I don't know what the setting looks like on a CDMA phone.

You can probably automate this with Tasker if you do want to use 3G where it is possible. Alternatively you could use a widget to change the setting manually without having to go to the settings menu. One app that provides a widget for this is Widgetsoid.