Battery sizer

What size battery does your home need?

Answer four questions. We size the battery to your usage, tariff, solar and EV, and estimate what it could save you each year.

1. Your home
3,900 kWh/yr
2. Your tariff
3. Solar
4. Electric car
8,000
Recommendation8.5 kWh

Sensible range 6 to 13 kWh

Est. saving / yr£442
Daily use16.9 kWh
Self-powered28%
  • Daily consumption ≈ 16.9 kWh including EV charging.
  • Sized to charge fully in the cheap overnight window and cover the day and evening at the off-peak rate.
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Estimates use 340 full cycles a year, 90% round-trip efficiency and 4p/kWh export. Actual savings depend on tariff and usage patterns.