Portable EV charger (cargador portátil, mode 2 granny cable)

What a portable charger is

A portable EV charger, often called a granny cable in the UK, is the lead many cars come with for charging from a socket. It is not just a cable: halfway along there is a box with control and protection electronics that talks to the car and cuts off if it detects a fault. The standards call this mode 2 charging.

How much power it gives

• On a normal Schuko socket the cable limits the current to about 10 A, roughly 2.3 kW. You add 10 to 13 km (6 to 8 miles) of range per hour.
• On a reinforced 16 A socket with its own circuit, about 3.7 kW and roughly 20 km per hour.
• Some models come with adaptors for industrial sockets that allow more power, as long as the installation is ready for it.

For a 60 kWh battery, charging on a Schuko takes a whole night and part of the day.

Risks of using any old socket

A household socket is not designed to deliver high current for hours. If it is worn, the cable is thin or the circuit is shared with other appliances, it heats up and can melt. Never use extension leads or multi-socket adaptors to charge a car.

When it makes sense

• Occasional charging at a relative’s home or a second home.
• Plug-in hybrids with small batteries.
• As a stopgap while your charging point is installed.

For daily charging

If you charge every day, the right choice is a mode 3 wallbox or, at least, a reinforced socket with a dedicated circuit and its own protection. See home EV charger for a house in Seville, Spain.