Spare/Replacement Internal Battery for 8" Zebra ET40 & ZT45 Tablets. This is a field Replaceable Internal Battery for the 8" Zebra ET4X tablets. Rechargeable Li-Ion 3.87V 6100mAh 23.61Wh PowerPrecision Battery - Obtains advanced battery state of health information including charge level and battery age based on usage patterns. Internal Battery charges only when inside the tablet.