Li-ion ≈ 3.7V, AA ≈ 1.5V, lead-acid ≈ 12V.
Accounts for regulator + heat loss. 80–90% typical.
Estimated runtime
—
— Wh · — mAh · draw — W
| Efficiency | Runtime | Watt-hours used |
|---|
How the math works
Convert capacity to watt-hours: Wh = (mAh × V) / 1000. Convert load to watts (W = V × A). Runtime in hours = (Wh × efficiency) / load watts.
Real-world runtime is shorter than ideal — voltage sags as the battery discharges, cold temperatures reduce capacity, and devices rarely draw a perfectly constant load.