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Batteries in Parallel Calculator

Capacity and energy of batteries wired in parallel, with the total current available.

Enter values

Results update as you type.

Result

Bank capacity

400 Ah

Parallel adds capacity but keeps voltage the same — use identical batteries and equal-length cables.

Bank voltage
12 V
voltage does not change in parallel
Total energy
4.8 kWh
Usable at 80% DoD
3.84 kWh
Runtime at 500 W
7.68 hours

About the Batteries in Parallel Calculator

Capacity and energy of batteries wired in parallel, with the total current available.

Also known as: parallel battery capacity, batteries in parallel, battery bank capacity parallel.

How to use this calculator

  1. Enter number of batteries, voltage each, capacity each.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Ah_total = n × Ah_each · voltage unchanged

Worked example

Using the values pre-filled in the calculator above:

  • Number of batteries = 4
  • Voltage each = 12 V
  • Capacity each = 100 Ah

the calculator returns:

  • Bank capacity: 400 Ah
  • Bank voltage: 12 V
  • Total energy: 4.8 kWh
  • Usable at 80% DoD: 3.84 kWh