Online Tool

Battery Bank Ah Calculator

Calculate total voltage, amp-hours, and watt-hours for series, parallel, and series-parallel battery configurations.

Configuration

Enter your battery specs and wiring layout.

Results

Calculated totals for your battery bank.

Total Voltage
12 V
Total Capacity
100 Ah
Total Energy
1200 Wh
Total Batteries
1
Total Energy (kWh)
1.20 kWh

Visual Layout

Frequently Asked Questions

How do I calculate the total Ah of a battery bank?

To calculate the total Ah of a battery bank, multiply the Ah rating of a single battery by the number of parallel strings. Batteries wired in series keep the same Ah as one battery, while batteries wired in parallel add their Ah together. For example, four 12V 100Ah batteries in a 2S2P configuration give 24V and 200Ah total.

Does wiring batteries in series increase amp-hours?

No. Wiring batteries in series increases the total voltage while keeping the amp-hour (Ah) capacity the same as a single battery. To increase Ah, you must wire batteries in parallel. A series-parallel configuration increases both voltage and Ah.

How many 12V batteries do I need for a 48V battery bank?

You need at least four 12V batteries wired in series to reach 48V (4 × 12V = 48V). If you also want more capacity, add parallel strings — each parallel string must contain the same number of series batteries. For example, a 48V 200Ah bank using 12V 100Ah batteries requires 4 series × 2 parallel = 8 total batteries.