Voltage is not the issue, increasing voltage WILL damage your battery. It's the amperage that would need the boost. Like at home, I have my HTC stock charger. Those push out 1000 milliamperes or ma ( 1 Amp ) At work I have an old motorola charger that pushes out 600ma. At work surfing the web with 1xRTT (no Ev-do here yet
) I chew up about 500-700ma depending on what else I am doing.
At home with the HTC charger running on wifi I don't seem to loose battery, I have not checked to see how much amperage it is eating up with wifi.
Wifi chews through batteries like crazy.