🔋 Battery Life Estimator
Estimate runtime from battery capacity and load current. Supports duty-cycle mode for devices with active and sleep states.
Battery Parameters
mAh
%
%
💡 Depth of Discharge (DoD): Lithium cells are typically discharged to 80–90% DoD to maximise cycle life. Lead-acid: 50%. NiMH: 80–100%.
System Efficiency: Accounts for DC-DC converter losses, self-discharge, and temperature derating. 85–95% is typical.
System Efficiency: Accounts for DC-DC converter losses, self-discharge, and temperature derating. 85–95% is typical.
Load — Simple (Constant Current)
$$\text{Runtime} = \dfrac{\text{Capacity} \times \text{DoD}\% \times \text{Eff}\%}{I_\text{avg}}$$
⚠ Please enter valid battery and current values.
Results
Battery Level
Load — Duty-Cycle Mode (Active + Sleep)
$$I_\text{avg} = I_\text{active}\,D + I_\text{sleep}\,(1-D) \qquad D = \dfrac{t_\text{active}}{t_\text{active}+t_\text{sleep}}$$
ms
ms
⚠ Please enter valid values (all fields required).
Results
Battery Level
Common Battery Capacities — Reference
| Battery | Nominal Voltage | Typical Capacity | Chemistry |
|---|---|---|---|
| CR2032 coin cell | 3.0 V | 210–240 mAh | Li-MnO₂ |
| AA alkaline | 1.5 V | 2400–3000 mAh | Alkaline |
| AA NiMH | 1.2 V | 1800–2800 mAh | NiMH |
| 18650 Li-ion | 3.7 V | 2000–3600 mAh | Li-ion |
| 21700 Li-ion | 3.7 V | 4000–5000 mAh | Li-ion |
| LiPo (typical wearable) | 3.7 V | 100–400 mAh | LiPo |
| LiPo (phone-size) | 3.7 V | 2500–5000 mAh | LiPo |
| 9V alkaline | 9.0 V | 400–600 mAh | Alkaline |