Amp-hours without voltage mis-rank battery size. This battery energy calculator (Wh) converts Ah and nominal V into watt-hours—the standard unit for stored energy across chemistries and bus voltages.
Benefits
- Core formula: Wh = Ah × V (kWh = Wh ÷ 1,000).
- Normalizes 100 Ah at 12 V vs. 48 V to comparable energy.
- First step before runtime, cost-per-Wh, and solar storage sizing.
How it works
- Enter battery capacity in amp-hours (Ah) from the label or spec.
- Add nominal system voltage (12 V, 24 V, 48 V, 3.7 V per cell, etc.).
- Read stored energy in watt-hours (Wh)—use for cross-voltage comparisons.
FAQ
How does the battery energy calculator (Wh) work?
Wh = Ah × V. Example: 100 Ah at 12 V → 1,200 Wh (1.2 kWh). The same 100 Ah at 48 V is 4,800 Wh—four times the energy despite identical amp-hour ratings.
Is Wh the same as usable energy?
No—this is nameplate stored energy at full charge. Usable Wh depends on depth of discharge, BMS reserve, and chemistry. Apply DoD after calculating gross Wh for planning margins.
How is this different from Ah to Wh converter?
Same math (Wh = Ah × V)—this tool is scoped to battery bank Ah and bus voltage. Use Ah to Wh when starting from mAh cell ratings or mixed units; both land on watt-hours for fair comparisons.
Technical specifications
- Stored Wh = capacity_Ah × voltage_V.
- kWh = Wh ÷ 1,000.
- Nominal V—use system bus, not float/charge peak.
- Related: battery-energy, ah-to-wh, battery-dod-energy-yield, battery-runtime.