Battery Parallel
Batteries in parallel
Add each battery's voltage and capacity. Total capacity is the sum; total voltage is the highest battery's.
Total (parallel)
How to use this calculator
Click "Add battery" for each cell in your parallel bank and enter its voltage and capacity. The total updates live: Ah_total = Ah₁ + Ah₂ + … and V_total = max(V). Use the "×" on a row to remove a battery. The tool also shows the bank energy (Wh = V_total × Ah_total).
What it means in a real circuit
Parallel connections add runtime (and available current) at the same voltage. Two 3.7 V / 2 Ah cells in parallel give 3.7 V / 4 Ah (≈14.8 Wh), so a given load lasts twice as long. Because the cells share current, a weak or mismatched cell can be over‑discharged, so use the same chemistry and age. Use this to plan the extra capacity you gain without changing the pack voltage.