WattCalc LAB

EV V2L Backup Runtime Calculator

Estimate vehicle-to-load backup runtime using EV battery capacity, protected driving reserve, conversion efficiency and household load.

Typical editable values; verify the exact model year and specification.

kWh
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W

How the calculation works

Estimate vehicle-to-load backup runtime using EV battery capacity, protected driving reserve, conversion efficiency and household load. Change every input to match your vehicle, equipment, tariff or measured consumption.

Runtime = battery capacity × available state-of-charge window × V2L efficiency ÷ average connected load.

Worked example

A 72.6 kWh battery used from 80% down to a protected 30% reserve makes 36.3 kWh available before conversion losses.

What can change the result?

  • The vehicle V2L outlet has a maximum continuous power limit.
  • Protect enough energy to reach a charger after the outage.
  • Never connect V2L to home wiring without approved transfer equipment and professional installation.

Frequently asked questions

Can I plug V2L directly into a wall socket?

No. Back-feeding building wiring can endanger people and equipment. Use approved equipment and a qualified electrician.

Does the car stay awake automatically?

Behaviour differs by vehicle. Follow the manufacturer instructions for utility mode or V2L operation.

Can it run a refrigerator and boiler?

Possibly, if combined running and startup power remain within the vehicle outlet limit.

Use the result responsibly

This calculator is intended for comparison and planning. Verify equipment limits, tariffs and important electrical decisions with the manufacturer, energy supplier or a qualified professional.