Power Systems
Battery Life Calculator
🔋 t = C / I
Calculate battery runtime, capacity, or current draw for any device.
Battery & Load
Battery Type
Select a battery type or choose Custom for manual entry
Battery Capacity
mAh
Battery capacity in milliamp-hours (mAh)
Battery Voltage
V
Nominal battery voltage
Load Current
mA
Current drawn by the load in milliamps (mA)
Load Power
W
Power consumption in watts (calculated from V×I)
Life
0h
Battery Life
0 h
estimated runtime
Battery Capacity
0 mAh
Load Current
0 mA
Energy Stored
0 Wh
Discharge Rate
0C
📊 Detailed Breakdown
| Parameter | Value | Unit |
|---|
How the formula works
Life (hours) = Capacity (mAh) / Current (mA) | Energy (Wh) = Voltage (V) × Capacity (Ah)
- Battery Life (hours) = Battery Capacity (mAh) / Load Current (mA)
- Energy Stored (Wh) = Battery Voltage (V) × Capacity (Ah)
- Discharge Rate (C) = Load Current (mA) / Capacity (mAh)
- Power (W) = Voltage (V) × Current (A)
- 1C = discharging at the rated capacity current
- Typical battery capacities: AA (2500mAh), AAA (1000mAh), 9V (600mAh), Phone (4000mAh), Laptop (6000mAh)
- Real-world battery life may vary due to temperature, age, and discharge characteristics