Battery Capacity Calculator (Vans)

Size your van’s battery bank from daily Wh, autonomy days, system voltage, and allowed DoD. Get required Ah and a practical module S×P configuration.

Is Wh/day affected by system voltage?

No. Wh/day is independent of V. Ah changes with V via Ah = Wh / V.

How much headroom should I add?

10–30% is common to cover colder temps, aging, and future devices.

Can I mix different battery sizes or chemistries?

Not recommended. Keep modules identical, same age/brand if possible.

What DoD should I use?

LiFePO₄: 80–90% typical. AGM: ~50% to preserve life.