Synergy Digital Tablet Battery, Compatible with Lenovo ThinkPad 1838 10.1 Tablet, (Li-Pol, 7.4V, 3200mAh) Ultra High Capacity, Replacement for Lenovo 42T4963 Battery Specifications: Battery Chemstry: Li-Pol Voltage: 7.4V Capacity: 3200mAh Compatible with: Lenovo 42T4963 Battery Works for: Lenovo ThinkPad 1838 10.1 Tablet and many more