Converting watt-hours to milliamp-hours takes one step: divide by the voltage. Ah = Wh / V, and mAh = (Wh / V) * 1000.
The same 100 Wh battery equals 27 Ah at 3.7V, but only about 2 Ah at 48V. That is why voltage matters as much as the energy rating.
Use the calculator below, or follow the worked examples.
Convert Watt Hours to mAh/Ah
| Application | Energy (Wh) | Voltage | Capacity |
|---|---|---|---|
| Solar Storage | 4,800Wh | 48V | 100Ah / 100,000mAh |
| Marine System | 3,600Wh | 36V | 100Ah / 100,000mAh |
| Truck Battery | 2,400Wh | 24V | 100Ah / 100,000mAh |
Wh to Ah and mAh Conversion: Formulas and Engineering Reference
Electric charge capacity in ampere-hours represents continuous current delivery over time, while watt-hours quantify total energy. The core conversion equations are:
Ampere-hours (Ah) = Watt-hours (Wh) / Nominal Voltage (V)
Milliampere-hours (mAh) = (Watt-hours (Wh) / Nominal Voltage (V)) * 1000
Common Industrial Device Power and Battery Capacity Reference
Sizing industrial hardware requires matching continuous wattage, system voltage, and required operating autonomy. Below is an engineering reference matrix across typical industrial equipment:
| Device / Application | Typical Power | System Voltage | Energy Rating (Wh) | Calculated Capacity (Ah) |
|---|---|---|---|---|
| Handheld Barcode Scanner | 5 Watts | 3.7V Li-ion | 14.8 Wh | 4.0 Ah (4000 mAh) |
| Industrial IoT Sensor Node | 0.5 Watts | 3.2V LiFePO4 | 6.4 Wh | 2.0 Ah (2000 mAh) |
| Field Thermal Camera | 12 Watts | 7.4V (2S) | 35.5 Wh | 4.8 Ah (4800 mAh) |
| Electric Utility Scooter | 350 Watts | 36V (10S) | 360 Wh | 10.0 Ah |
| Portable Power Station | 500 Watts | 51.2V (16S) | 1024 Wh | 20.0 Ah |
| Industrial Electric Forklift | 4500 Watts | 48V System | 9600 Wh | 200.0 Ah |
Frequently Asked Questions
Why does system voltage directly determine battery capacity calculations?
Voltage dictates current flow requirements for any power load. Higher system voltage delivers identical watt-hours with significantly lower continuous amperage, reducing cabling resistive losses and permitting smaller ampere-hour capacity ratings.
How do you convert milliamp-hours and amp-hours back into watt-hours?
Multiply ampere-hours by nominal voltage: Wh = Ah * V. For milliamp-hours, calculate Wh = (mAh * V) / 1000. You can also utilize our interactive tool.
What is the fundamental difference between mAh and Ah ratings?
Both units measure electrical charge capacity over time. One ampere-hour equals exactly 1000 milliampere-hours. The unit mAh suits compact electronics such as sensors and smartphones, whereas Ah designates large systems including traction packs and stationary solar banks.
