- Capacity: 1000mAh 3.7Wh-2. Input: USB: 5V/1A-3. Output: iWatch: 2.5W (compatible with iWatch 1-10, SE/SE2, Ultra/Ultra2)-4. Display: LED light shows the power level-5. Material: ABS+PC flame retardant shell+lithium polymer cell-6. Size: 684016mm; Weight: 43g