Lenovo ThinkPad Battery 77 (4-cell)

The ThinkPad battery 77 is a replacement or spare battery for P50 and P51 laptops. The 77 battery is rechargeable and is powered by Lithium-ion technology and has a safeguard chip which authenticates with Lenovo systems. The battery lasts on average 66 watt hours* and has over-discharge protection to ensure a secure flow of power.*Battery life varies due to many factors. These include: applications, battery conditioning, features, screen brightness, power management and other customer preferences.