Battery Power Calculator

Calculate the power a battery can deliver and the C-rate that implies.

About Battery Power Calculator

Battery power capability is set by the C-rate limit, which is independent of energy capacity. A bank can hold plenty of energy yet be unable to deliver the required power. Power-limited applications such as EV charging or welding often need a larger bank than the energy requirement alone suggests.

Formula

Battery Power

Maximum power = capacity × C-rate × voltage

C-rate limit: Manufacturer limit on continuous discharge current

Worked example

With the default values below, Battery Power Calculator returns Maximum Continuous Power of 5,120.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Capacityminimum 0 Ah: 200 Ah
Nominal voltageminimum 0.1 V: 51.2 V
Maximum continuous C-rateaccepts 0.01–10 C: 0.5 C
Desired output powerminimum 0 W: 5,000 W

Results

Maximum Continuous Power: 5,120.00 W
Maximum Continuous Current: 100.00 A
C-Rate for the Desired Power: 0.4883 C
Runtime at the Desired Power: 2.048 h
Verdict: Close to the continuous limit

Step by step

1Values used
2Battery Power
3Maximum Continuous Power= 5,120.00 W
4Maximum Continuous Current= 100.00 A
5C-Rate for the Desired Power= 0.4883 C
6Runtime at the Desired Power= 2.048 h
7Verdict= Close to the continuous limit

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Battery Power calculated?

Maximum power = capacity × C-rate × voltage Battery power capability is set by the C-rate limit, which is independent of energy capacity. A bank can hold plenty of energy yet be unable to deliver the required power.

Why does Battery Power matter?

Power-limited applications such as EV charging or welding often need a larger bank than the energy requirement alone suggests.

What values do I need to enter?

This calculator takes 4 inputs: Capacity, Nominal voltage, Maximum continuous C-rate, Desired output power. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.