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How Long Do 12V Batteries Last in Electric Vehicles?
When most people think about an electric vehicle battery, they picture the big high-voltage pack that drives the car. But every EV also has a 12V battery, and just like in petrol or diesel cars, it doesn’t last forever.
So how long does a 12V battery in an electric car really last, and what can you do to extend its life? Let’s break it down.
Average Lifespan of a 12V EV Battery
On average, a 12V battery in an electric vehicle lasts 3–5 years. However, the actual lifespan depends on:
- Climate – Extreme cold or heat reduces battery efficiency and shortens life.
- Driving habits – Short trips or infrequent driving can leave the 12V battery undercharged.
- Charging cycles – EVs rely on a DC/DC converter to keep the 12V battery charged from the high-voltage system. If the car is rarely driven, the 12V may not get topped up as often.
- Electrical load – Modern EVs have 50+ electronic control units. Driver assistance, infotainment, and safety features all increase demand on the 12V system.
Why EV 12V Batteries Wear Differently
In petrol and diesel cars, the alternator charges the 12V battery while driving. In an EV, the high-voltage battery powers a converter, which then keeps the 12V charged. This difference means that:
- The 12V battery is in constant use, even when the car isn’t being driven.
- If the car sits idle for long periods, the 12V battery can discharge completely.
- Deep discharge cycles can shorten battery life significantly.
Signs Your 12V Battery Is Failing
Knowing when your 12V battery is getting weak can prevent breakdowns. Look out for:
- Dashboard warning lights
- Slow or unresponsive infotainment systems
- Difficulty with central locking or alarms
- Reduced performance of wipers, steering, or brakes
How to Extend the Life of Your 12V Battery
With proper care, you can get the most out of your EV’s 12V battery:
- Drive regularly – even short trips keep the 12V topped up.
- Avoid long idle periods – if storing your EV, consider a trickle charger.
- Book regular battery checks – early testing helps prevent sudden failures.
- Replace proactively – don’t wait for complete failure; plan a replacement every 3–5 years.
Replacement and Maintenance
Unlike the high-voltage system, 12V batteries are straightforward to replace, but they must be correctly matched to your vehicle. EVs often use AGM or lithium 12V batteries, which need expert fitting to ensure proper integration with onboard electronics.
Get Your 12V Battery Checked at Battery Town
At Battery Town, we stock the right 12V replacement batteries for electric vehicles and hybrids. Our nationwide network offers:
- Free battery testing
- Expert advice on the right 12V battery for your EV
- Professional fitting for maximum safety and reliability
Book your free battery check at Battery Town today and keep your EV safe, connected, and on the road.