What does it mean for the battery?
The owner's first question to the installer: will this wear out my battery?
The installer answers with a number: how much extra energy will pass through it in a year.
The questionHow much does powering the house add to the battery's work?
15,000 km at 17 kWh per 100 km
6 kWh on 200 evenings
of a 70 kWh battery
added on top
A composed household. V2H adds about 47% to the energy that passes through the battery each year, at the low power of a home.
What drives ageing
Batteries age with time and with use. In a large telematics study, frequent fast charging above 100 kW went with faster capacity loss, up to 3.0% a year, while mostly AC or lower-power charging went with about 1.5%. Powering a house is low-power use, closer to AC charging than to fast charging. How cells age in general is explained in eMobility and EV basics, stop 08.
Data and limits
- Data: RED III asks Member States to require that vehicle manufacturers make battery data available in real time, including and , to owners and third parties acting for them.
- Limits: owners set a floor and a departure time; manufacturers can set limits on how much energy may flow out, and their warranty terms say what applies.
Check your understanding
3 questions. Answer all of them to complete this stop. Each answer explains itself.
A household feeds 6 kWh on 200 evenings. How much energy is that per year?
6 × 200 = 1,200 kWh.
Which charging behaviour went with the fastest ageing in the telematics study?
Up to 3.0% a year with frequent fast charging, about 1.5% with mostly AC charging.
Which battery data does RED III want manufacturers to share?
Article 20a(3) lists state of health, state of charge, power set point and capacity.
- State of charge How full the battery is right now, in percent; the BMS calculates it from voltage, current and temperature. eMobility and EV basics, stop 02 Glossary
- State of health How much energy the battery can hold today compared with when it was new, in percent. eMobility and EV basics, stop 08 Glossary
- Geotab: Updated analysis finds average battery degradation of 2.3% per year, with charging behaviour emerging as a key driver, 13 January 2026. https://www.geotab.com/uk/press-release/ev-battery-health-degradation-fast-charging-study/. Checked 09 Oct 2026.
- EUR-Lex: Directive (EU) 2023/2413 (RED III), Article 20a inserted into Directive (EU) 2018/2001. https://eur-lex.europa.eu/eli/dir/2023/2413/oj. Checked 09 Oct 2026. © European Union, reused under Commission Decision 2011/833/EU.