Battery Series/Parallel Calculator

When wiring batteries together, connecting them in series raises voltage while parallel connections increase capacity — the Battery Series/Parallel Calculator works out exactly what your pack will deliver. Enter your battery voltage, battery capacity, series count, and parallel count, then adjust depth of discharge and system efficiency to get your pack's total voltage, total capacity, usable capacity, total energy in Wh, and total battery count.

V
Ah

Number of batteries connected in series (increases voltage)

Number of batteries connected in parallel (increases capacity)

%

Maximum discharge level for battery safety

%

Overall system efficiency including wiring losses

Results

Total Voltage

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Total Capacity

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Usable Capacity

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Total Batteries

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Total Energy

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Frequently Asked Questions

How do series and parallel connections affect battery performance?

Series connections add voltages together while keeping capacity the same. Parallel connections add capacities together while keeping voltage the same. Most battery packs use a combination of both to achieve desired voltage and capacity.

What is depth of discharge and why is it important?

Depth of discharge (DoD) is the percentage of battery capacity that has been used. Most batteries last longer when not fully discharged. Lithium batteries can typically handle 80-90% DoD, while lead-acid batteries should not exceed 50% DoD.

How do I calculate how many batteries I need?

Divide your target voltage by individual battery voltage to get series count. Divide your target capacity by individual battery capacity to get parallel count. Total batteries = series count × parallel count.

What safety considerations should I keep in mind?

Always use identical batteries in the same configuration. Include proper fusing and battery management systems. Ensure adequate ventilation and temperature monitoring. Follow manufacturer guidelines for charging and discharging.

Why is system efficiency important in calculations?

Real systems have losses from wiring resistance, inverters, and other components. System efficiency accounts for these losses, typically ranging from 75-95%. This ensures your calculations reflect real-world performance.

Can I mix different types of batteries?

No, you should never mix different battery types, ages, or capacities in the same configuration. This can lead to imbalanced charging, reduced performance, and potential safety hazards.