ENERGY CAPACITY
—
Wh | — kWh
Usable Energy:
— Wh
Runtime at 100W:
— hours
AMP HOURS TO WATT HOURS
Amp Hours to Watt Hours Calculator: Battery Capacity Conversion
An amp hours to watt hours calculator converts battery capacity from ampere-hours (Ah) to watt-hours (Wh) by multiplying by the nominal voltage. This essential calculation determines how much energy a battery can store and deliver.
There are 4 key applications for Ah to Wh conversion: solar battery system sizing, electric vehicle range calculation, portable power bank capacity assessment, and energy storage system planning. The 3 most common mistakes are forgetting voltage variations, ignoring efficiency losses, and miscalculating runtime without considering discharge rates.
Amp Hours to Watt Hours Calculator
Amp Hours to Watt Hours Formulas
Basic Conversion
Wh = Ah × V
Where:
Wh = Watt-hours
Ah = Amp-hours
V = Voltage
With Efficiency
Wh = Ah × V × (η ÷ 100)
Where:
η = Efficiency percentage
Energy Over Time
E = P × t
Where:
E = Energy (Wh)
P = Power (W)
t = Time (hours)
Calculation Examples
Solar Battery
100Ah 12V battery:
100 × 12 = 1200Wh
At 90% efficiency: 1080Wh usable
EV Battery
50Ah 400V battery:
50 × 400 = 20,000Wh = 20kWh
Typical range: 100-150 miles
Power Bank
20000mAh 5V battery:
20 × 5 = 100Wh
Charges phone ~4-5 times
Frequently Asked Questions
How do I convert amp hours to watt hours?
Watt-hours = Amp-hours × Voltage. For example, a 100Ah 12V battery stores 100 × 12 = 1200Wh.
What is the difference between Ah and Wh?
Amp-hours measure electrical charge capacity, watt-hours measure energy capacity. Voltage bridges the two units.
Why is efficiency important in battery calculations?
Batteries have internal losses. A battery rated at 100Ah might only deliver 85-95Ah usable capacity due to Peukert effect and temperature.