Why a car with charge can still refuse to start
An electric car has two batteries. The big one drives the wheels. A small 12 V battery, much like the one in a petrol car, runs the locks, the screens, the computers and the contactors that connect the big battery to the motor. If the 12 V battery is flat, the car can refuse to wake up even when the big battery is full.
That means a car can show plenty of charge one day and be dead the next. It is one of the more common reasons for an electric car to stop working, and it is not something a top-up charge can solve.
Signs it may be the 12 V battery
None of these prove it, but together they point that way:
- The dashboard stays dark or only flickers when you press the start button
- You never get the Ready light or the car sounds
- The key fob or app won't open the doors, or the doors open but nothing else happens
- A warning about the 12 V battery or the charging system appeared in the last few days
- The car has sat unused for a few weeks, or it's been very cold
Check these first
Before you ring anyone, rule out the simple things. They only take a minute.
- Is your foot firmly on the brake when you press start?
- Is the car in Park, and is the charging cable fully unplugged?
- Does the key fob have a working battery? Many cars have a spot where you can hold a flat fob against the car
- Is the car in a sleep or transport mode? Your handbook will say
When a mobile charge will and won't help
A mobile charge helps when the big battery is low. If your screen shows a low percentage, or the car slowed down and stopped on you, that is what we do: we plug in our 7.5 kW charger and add an estimated 10 to 12 miles in 30 minutes, enough to reach a proper charge point. The miles vary with the car, temperature and battery state.
If the screen shows plenty of charge and the car is dead, a charge usually won't help. That is a job for your breakdown provider, the dealer or a mobile mechanic. We only do mobile charging. We don't tow, jump-start or repair cars, and we'll tell you straight away if what you describe sounds like something else.
What to say when you ring
Tell us the make, model and year, what the dashboard shows, the battery percentage if you can see it, and exactly where you are. Say what you've already tried. With that, we can usually tell on the call whether it sounds like a low battery, in which case we'll tell you the price and come out, or something else, in which case we'll say so and save you waiting for the wrong help.
Published