According to its feature page, the 6-cell lithium-ion battery that comes with the G51VX lasts up to 2 hours and 7 minutes. To test out all battery life claims, we use the notebook benchmark tool BatteryEater Pro running in Classic mode and record the time it takes for the laptop to shut down.
After 1 hour and 44 minutes, the G51VX used up a full charge. The battery life we experienced was on par with Lenovo's G530 which also sports a 6-cell battery. Keep in mind, our benchmark puts a continuous heavy load on the graphics card as well as the CPU so we don't feel that the 2 hour 7 minute battery life is misleading at all. With a lighter workload, the machine would have been able to hit that mark. At any rate, it gives you just enough battery life to watch a movie or play a few rounds of your favorite game during a flight.