Battery Life Calculator
Estimate runtime for any battery-powered project. Enter battery capacity (mAh) and average current draw to get hours of runtime. Includes efficiency factor for real-world derating.
Battery Runtime Estimation
Calculates how long a battery will last under a given average current draw. Accounts for regulator/conversion efficiency, battery chemistry voltage drop, and usable capacity. Works for any battery chemistry (alkaline, Li-ion, NiMH). Remember: actual runtime depends on current profile and temperature.
Estimated runtime: 17.0 hours
Common: 18650 = 2000–3500 mAh · AA = 2500 mAh · LiPo 1S = 1000–5000 mAh
ESP32 active ≈ 160–240 mA · deep sleep ≈ 0.01 mA · Arduino Uno ≈ 50 mA
Accounts for voltage regulator loss and battery chemistry derating (80–90% typical)
Estimated Runtime
17.0 hours
- Hours
- 17.00 h
- Days
- 0.71 d
- Weeks
- 0.10 wk
- Usable capacity
- 1700 mAh
Runtime = (Capacity × Efficiency) / Current
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