Vehicle-to-vehicle charging (V2V): how to help a stranded EV

Short answer: vehicle-to-vehicle (V2V) charging means transferring energy from one EV's battery to another EV. The most common way is to plug a V2L adapter into the charging port of a V2L-capable car and connect the second car's portable charger to the adapter's socket. It is slow (usually 2–3.6 kW) and some energy is lost; the aim is to give enough range to reach the next charger, not to replace regular charging. Check both owner's manuals first: some manufacturers do not allow charging another vehicle from the V2L outlet.

Ways to charge car to car

1. V2L + portable charger (AC): a V2L adapter on the giving car, a portable charger on the receiving car. Little extra equipment, low speed. This is the most common method.
2. Direct DC V2V cable: some manufacturers offer special cables linking the DC ports of two cars. Faster, but only works on cars that support it; not common.
3. Bidirectional charging (V2G/V2H): transfer via a bidirectional home charger; car and charger support is still limited.

This guide covers the first method.

What you need

• Giving car: an EV with V2L. What V2L is and which cars have it: what is V2L?
• V2L adapter: plugs into the car's Type 2 port and ends in a standard socket; choose the version for your car.
• Portable charger (Mode 2): owned by the receiving car; ideally one whose current can be set to 10 A.

Step by step

1. Park both cars side by side with their charging ports close; both in park.
2. Enable V2L on the giving car and set a battery limit (e.g. 20–30%) so it doesn't get stranded too.
3. Plug the V2L adapter into the giving car.
4. Plug the portable charger into the adapter's socket and its Type 2 connector into the receiving car.
5. Set a low current (10 A); if the V2L limit is exceeded, the giving car cuts the output.
6. Monitor the charge; when finished, stop charging on the receiving car first, then unplug.

Don't use extension leads, and keep cables from becoming a trip hazard.

How much range does it give?

V2L output is 2.2–3.6 kW on most cars, and both the giving car's inverter and the receiving car's charger lose some energy. Rough estimate: a 3 kW transfer gives the receiving car about 2.5 kWh per hour; for a car using 16–20 kWh per 100 km that is roughly 12–15 km per hour. The giving car spends about 3–3.5 kWh for it. Values vary by car, temperature and equipment.

When does it make sense?

• The battery ran out a few kilometres short of a charger.
• In rural areas where chargers are far and roadside assistance is slow.
• Off-grid at a campsite or holiday home when one car is full and the other empty.

It is not an everyday charging method: slow, lossy and drains the giving car. Charging at home or at a public charger is cheaper and faster; your roadside assistance may also offer mobile charging.

• → V2L adapters
• → Portable EV chargers
• → What is V2L?
• → Choosing a portable charger
• → EV range
• → Driving an EV in winter