With HTC's Thunderbolt finally in stores, questions of the device's battery life has returned to the fore. Reviewers of the device have praised the Thunderbolt's quick speeds and slick interface, but they've also almost universally maligned the device's battery life.

Battery life remains a constant issue for smartphones, and the Thunderbolt is not immune to the concerns. While the device's large screen and video capabilities hold a portion of the blame, much of the cause for the device's paltry battery life seems to appear when it's connected to Verizon's LTE network.

PCMag reported 2.5 hours of battery life while using the Thunderbolt on LTE. SlashGear got similar results, logging 2 hours and 45 minutes of battery life while on LTE. Laptop magazine found similar results.

The Thunderbolt's official talk time is 6.3 hours, with a stand by time of 330 hours. These metrics do not take into consideration the likely usage patterns for Thunderbolt owners, who are certain to take advantage of the device's multimedia capabilities.

Concern over the Thunderbolt's battery life has been so pronounced that it inspired Verizon to create a high-capacity battery that the company will sell for $49.99. The standard Thunderbolt battery costs $39.99.

At 2750 mAH, the larger battery nearly doubles the capacity of the one built into the phone. It also adds an ounce to the device's weight, making the Thunderbolt 7.7 ounces.

Verizon has not announced a release date for the beefed-up battery.