EV V2L Backup Runtime Calculator
Estimate vehicle-to-load backup runtime using EV battery capacity, protected driving reserve, conversion efficiency and household load.
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How to choose the inputs
Confirm that the exact vehicle and adapter support V2L. The form compares the entered continuous load with your entered output limit and rejects a load above that limit. It does not verify the rating, adapter compatibility, startup surge or automatic cutoff settings. A calculated runtime is not proof that an appliance can start. Never backfeed household wiring through a wall socket.
Formula and measurement boundary
Three worked scenarios
These are fixed hypothetical examples, not live tariffs or verified product data. They use EUR and kilometres where applicable and do not change with the form settings. Only the table input changes.
Unchanged inputs
- Usable EV battery capacity: 60 kWh
- Starting charge: 80 %
- Driving reserve: 20 %
- V2L efficiency: 90 %
| Average connected load | Estimated result |
|---|---|
| 300 W | 4.5 days |
| 600 W | 2.3 days |
| 1,200 W | 27 h 0 min |
These hypothetical inputs leave 12 kWh for driving and deliver 32.4 kWh to loads. The estimates are 108, 54 and 27 hours. They do not claim that every EV can provide V2L or that these loads suit a particular adapter.
What this result does not establish
- Whole-home backup is not the same as powering standalone appliances; compatibility and safe isolation require a qualified professional.
- Vehicle minimum-charge cutoffs, standby draw and automatic timeouts are not simulated.
- The manufacturer source is a historical example, not an approval of a connection or confirmation of all catalogue entries.
Preserve the driving reserve and check the loads that start together
The following are additional hypothetical decision examples. Separately discussed fees, reserve allowances or running costs are not automatically added to the form result.
For an illustrative 60 kWh usable vehicle battery starting at 80% and stopping V2L at 30%, available energy is 30 kWh. At 90% delivery efficiency and a steady 500 W load, runtime is 54 hours. The remaining 30% is a chosen driving reserve, not energy available to the backup calculation. Check the vehicle’s own V2L stop setting: it may differ from your chosen scenario.
A 2 kW kettle plus 500 W background load requires 2.5 kW while the kettle runs. That may exceed the entered output ceiling even though the energy needed for ten minutes is small. Motors can also require a starting surge above their steady rating. The calculator compares the average load with the entered continuous limit; it cannot verify the adapter, the actual vehicle output or a transient surge.
Confirm regional V2L support and the approved adapter in the vehicle manual. Power standalone appliances through the intended output; never energise household wiring through a wall socket. Whole-house connection needs designed transfer equipment and qualified installation. Test the intended devices, preserve a route-to-charger reserve and plan what happens when the car must leave.
Sources and their scope
- Hyundai: original IONIQ 5 announcement — Historical V2L example; not verification of the vehicle catalogue.
These reference pages were accessed on 21 September 2026. The equations and examples are the site’s own model; these sources do not certify its defaults or results.
Frequently asked questions
Does a positive duration mean the load will work?
No. The entered continuous limit is checked; start-up surge, adapter compatibility and actual vehicle limits require separate verification.
Can I rely on it for safety-critical backup?
No. Critical equipment requires an independently assessed backup arrangement, not this runtime estimate.
Read the model and verification limits