Battery Life Calculator
Calculate how long your battery will last based on capacity and load current.
Battery Parameters
Typical: AA (2000-3000 mAh), AAA (800-1200 mAh), 18650 (2000-3500 mAh)
V
Typical: Li-ion (3.7V), NiMH (1.2V), Alkaline (1.5V), Lead-acid (12V)
Average current consumption of your device
%
Account for voltage regulator, converter losses, etc. (typically 80-95%)
Battery Life Results
Battery Life
20.00 hours
1200 minutes
Battery Capacity
7.40 Wh
Watt-hours (energy capacity)
Power Consumption
0.370 W
Average power draw
Discharge Rate (C-rate)
0.050C
Low discharge rate (good for battery life)
Formula Used
Battery Life (hours) = (Capacity / Current) × Efficiency
Capacity: 2000 mAh, Current: 100 mA, Efficiency: 100%
Important Notes
- Actual battery life may vary based on temperature, age, and discharge characteristics.
- Battery capacity decreases over time and with temperature extremes.
- For intermittent loads, calculate average current consumption over time.
- C-rate above 1C may reduce battery life and capacity.
- Always include a safety margin (20-30%) for real-world applications.