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Home Battery Calculator

Estimate home battery capacity, backup autonomy and inverter power before comparing domestic battery products.

Home profile

This is an estimate for shopping guidance, not an electrical installation design.

Recommended home battery

5-10 kWh
Minimum usable capacity6 kWh
Nominal capacity8 kWh
Estimated autonomy12.2 h
Suggested inverter2 kW+
Suitabilitygood
Solar noterecommended

Energy systems

Battery goal

What do you want the battery for?

Backup essentials

Practical recommendation

Best range: Medium battery (5-10 kWh)

  • 3 people and this home profile suggest roughly 16 kWh/day before battery losses.
  • Your backup selection is estimated around 0.6 kW for 8 hours.
  • Solar production makes the battery more useful for self-consumption and evening use.

Limits to remember

  • Capacity in kWh is not enough: the inverter must also handle the devices you want to start and run.
  • Ovens, induction hobs, heat pumps, boilers and EV chargers can drain a home battery very quickly.
  • Real usable capacity depends on chemistry, depth of discharge, inverter limits, temperature and installer settings.

Buying shortcut

From sizing to a realistic shortlist.

Use the calculator to avoid buying too small, then compare product picks with the right capacity, output power and use case in mind.

Open calculatorSee product picksRead the guide

Frequently asked questions

Is kWh the same as inverter power?

No. kWh is stored energy. Inverter power in kW determines which appliances can start and run at the same time.

Can a home battery work without solar panels?

Yes, especially for backup or dynamic tariffs, but the financial case is usually stronger when the battery stores solar production.

Can I power the whole home?

Sometimes, but whole-home backup usually needs a larger battery, a stronger inverter and a proper installation. Essential-load backup is often more realistic.

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