Jack Gold, an analyst at J. Gold Associates, said it isn't completely clear how much LTE chips will drain batteries. "Early indications are that the LTE chipsets draw more power than older chipsets," similar to when phones upgraded from 2G to 3G, he said. "LTE will likely cause some power issues in early-gen devices."

He said the power drain will come more from the LTE radio than the phone's 1GHz processor, even though an LTE phone could be used to play and process much more video since the LTE network is 10 times faster than Verizon's 3G CDMA/EV-DO network.

Verizon lists the average download speeds with LTE on the ThunderBolt at between 5 Mbit/sec and 12 Mbit/sec, with upload speed between 2 Mbit/sec and 5 Mbit/sec.

The phone converts from LTE to Verizon's 3G network where LTE is not available, and some analysts said the switching back and forth will also tend to drain the battery more than in one network. Verizon has LTE in 39 cities so far.

"We'll probably have to wait until some devices get out there and tested to know for sure what the powerimpact of LTE will be," Gold said.