Every electric vehicle (EV) has two batteries: the big high-voltage pack that drives the car and the smaller 12V battery that powers electronics and safety systems. While the high-voltage pack gets most of the attention, the 12V battery is just as critical, and it wears out much faster.

Most EV 12V batteries last 3–5 years, but how do you know when it’s time for a replacement?

Here are the top 5 warning signs to watch for.

1. Dashboard Warning Lights

A weak 12V battery often triggers warning messages or icons on your dashboard. These can include:

  • “12V Battery Low” or “Battery Needs Service” alerts
  • Unexpected system errors, even if the high-voltage battery is fine

If your EV is showing unusual electrical warnings, the 12V battery could be the culprit.

2. Electronics Acting Up

The 12V battery powers your EV’s infotainment, navigation, lights, and driver assistance systems. If you notice:

  • Flickering interior or dashboard lights
  • Slow or unresponsive touchscreen
  • Sound system cutting out

…it’s often a sign your 12V battery is losing strength.

3. Central Locking or Alarm Problems

Struggling to unlock your car with the remote? Alarm not arming properly? These everyday functions are directly powered by the 12V battery. When they start to fail, it’s time to get your battery checked.

4. Safety Features Not Working Correctly

Some of your EV’s most important safety systems depend on the 12V battery, including:

  • Power steering
  • Brake booster
  • Windscreen wipers

If any of these feel sluggish or fail altogether, a weak 12V battery could be putting your safety at risk.

5. Complete Non-Start Condition

Unlike a petrol or diesel car, an EV won’t crank when the 12V battery dies it simply won’t turn on at all. Even if your high-voltage battery is fully charged, your EV can be immobilised by a flat 12V battery.

What to Do if You Notice These Signs

If your EV shows any of the above symptoms, don’t wait until you’re stranded. A free battery check can confirm whether your 12V battery needs replacing.

At Battery Town, we:

  • Test your 12V battery’s health
  • Stock the right 12V replacements for EVs and hybrids
  • Provide expert fitting for maximum reliability

Keep Your EV Safe and Reliable

The 12V battery is the heart of your EV’s safety and electronics. Don’t let a weak battery compromise your driving experience.

Visit your local Battery Town today for a free battery check and professional replacement service.

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