Battery Energy Calculator
Calculate battery energy step by step: Pack V = cell V × series count; pack Ah = cell Ah × parallel count; Energy (Wh) = pack V × pack Ah.
In short
Formula: Pack V = cell V × series count; pack Ah = cell Ah × parallel count; Energy (Wh) = pack V × pack Ah.
Stored energy
86.4 Wh
- Pack voltage
- 14.4 V
- Pack capacity
- 6 Ah
- Kilowatt-hours
- 0.0864 kWh
- Megajoules
- 0.311 MJ
What this calculator does
Calculate battery energy step by step: Pack V = cell V × series count; pack Ah = cell Ah × parallel count; Energy (Wh) = pack V × pack Ah. Worked example, questions and limitations included.
Use it to turn Capacity per cell or battery, Nominal voltage, Cells in series, Strings in parallel into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this electrical calculation.
Inputs and what they mean
- Capacity per cell or battery
- — number value.
- Nominal voltage
- — number value.
- Cells in series
- — number value.
- Strings in parallel
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Series adds voltage, parallel adds capacity; energy is the product.
Cell counts must be positive whole numbers.
Uses nominal voltage, which is the usual basis for rated energy.
Pack V = cell V × series count; pack Ah = cell Ah × parallel count; Energy (Wh) = pack V × pack Ah.
Inputs used: Capacity per cell or battery, Nominal voltage, Cells in series, Strings in parallel.
Worked example
4S2P pack of 3.6 V 3 Ah cells
- Voltage: 3.6 × 4 = 14.4 V.
- Capacity: 3 × 2 = 6 Ah.
- Energy: 14.4 × 6 = 86.4 Wh.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Nominal rating only; actual energy varies with rate and temperature.
- Assumes identical, balanced cells.
- Ageing is ignored.
- Results are estimates for planning and learning. Real designs, installations and bids must be checked by a qualified, licensed professional against the codes that apply where you work.
- The result depends on the values you enter for this battery energy calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Why do airlines ask for watt-hours?
Watt-hours measure stored energy regardless of voltage, so they are used for battery transport limits. Check your airline's current rule.
Is mAh the same as Wh?
No. mAh ignores voltage. Divide mAh by 1,000 to get Ah, then multiply by voltage to get Wh.
Is all this energy usable?
No. Depth of discharge limits and conversion losses reduce usable energy; the battery runtime calculator accounts for both.
How do I use the Battery Energy Calculator?
Enter the required values for Capacity per cell or battery, Nominal voltage, Cells in series, Strings in parallel. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Battery Energy Calculator use?
Pack V = cell V × series count; pack Ah = cell Ah × parallel count; Energy (Wh) = pack V × pack Ah. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Battery Energy Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Related tools
Calculate electrical power step by step: P = V × I = I² × R = V² ÷ R (DC or resistive AC using RMS values).
Calculate voltage divider step by step: Vout = Vin × R2 ÷ (R1 + R2).
Calculate resistance step by step: R = V ÷ I, or for a conductor R = ρ × L ÷ A (A in m²).