iFixit Keyboard Battery Compatible with Surface Book 2 13.5" 1835 This Keyboard Base replacement battery is what you need to bring your dead keyboard back to life! Battery degradation is an inevitable part of your keyboard base's lifespan — extend it with this replacement battery compatible with the 1835 model Surface Book 2 13.5". If your keyboard won’t turn on, won’t hold a charge, or you simply experience poor battery life, this replacement battery may be what you need to fix it. Specifications Part #G3HTA049H, G3HTA050H Watt Hours: 59.4 Wh Voltage: 11.36 V Milliamp Hours: 5218 mAh Note For optimal performance, calibrate your newly installed battery: Charge it to 100% and keep charging it for at least 2 more hours. Then use your device until it shuts off due to low battery. Finally, charge it uninterrupted to 100%.