Battery Series
Batteries in series
Add each battery's voltage and capacity. Total voltage is the sum; total capacity is the smallest battery's.
Total (series)
How to use this calculator
Click "Add battery" for each cell in your series string and enter its voltage and capacity. The total updates live: V_total = V₁ + V₂ + … and Ah_total = min(Ah). Use the "×" on a row to remove a battery. The tool also shows the pack energy (Wh = V_total × Ah_total).
What it means in a real circuit
Series connections raise the pack voltage while the current and runtime are limited by the smallest cell — that's why the capacity is the minimum, not the sum. Four 3.7 V / 2 Ah Li‑ion cells in series give a 14.8 V / 2 Ah pack (≈29.6 Wh). Mismatched cells reduce usable capacity and can over‑discharge a weak cell, so keep the same chemistry and age. Use this to plan the voltage you need and to see that capacity does not multiply in series.