Electric or hybrid car will not wake up?

What we do
We wake the car by its 12V battery, using the jump point the maker intended.
For
EVs and hybrids that will not unlock or go to ready
Price
One call-out price, no distance charge
Connecting a lead to the 12V battery of an electric car at dusk

It feels wrong: the app says the main battery is full, and the car will not unlock, the screens stay black, or it will not go into ready. The cause is usually not the big battery at all.

The EV 12V battery nobody mentions in the showroom

Electric and hybrid cars carry a small 12V battery, much like the one in a petrol car. It powers the locks, the computers and the system that switches the high-voltage battery on. When it runs flat, the car cannot wake itself up, no matter how much charge sits in the main pack.

Gloved hands on the 12V jump terminal of a hybrid, away from the orange high-voltage cables
On a hybrid we use the 12V jump point and leave the orange cables alone.

Why it goes flat

  • The car has been parked for a week or two, and some systems stay awake while it sits
  • Short journeys, so the small battery is rarely topped up properly
  • Cold nights, which weaken any battery
  • The 12V battery is simply old

What we need from you

The make, the model and the year. Some cars hide the 12V battery in the boot or under a seat, and many give you a dedicated jump point under the bonnet instead. A few makers ask for a particular method. With the model in front of us we can tell you on the phone whether we can help, and how.

What not to do

  • Do not use your EV to jump another car unless the handbook says you can
  • Do not connect ordinary leads to the high-voltage system or anything with orange cables
  • Do not keep pressing the start button: wait a minute and try once

If it keeps happening

A 12V battery that goes flat again within days is usually worn out. Replacing it is a small job compared with the cost of the car, and worth doing before the winter properly starts.

Questions about this

Is it safe to jump an electric car?

Done through the 12V battery or the maker's jump point, in the way the handbook describes, yes. That is why we ask for the model first.

Can my EV jump someone else's car?

Only if the handbook says so. Many makers say no.

The app says the car is charged. Why will it not start?

Because the app is reporting the main battery. The small 12V battery that wakes the car up is a different battery.