Start-Stop Vehicles and Your Battery: What Changes

Many newer cars shut the engine off when you stop at a light and restart it when you lift off the brake. It saves fuel, but it means the battery restarts the engine dozens of times on a single trip.

Why these cars need a different battery

Start-stop vehicles generally need an AGM or EFB battery designed for frequent cycling. A standard battery can wear out far sooner in this role, and the system may stop working.

The system watches the battery

Most start-stop cars have a sensor that monitors the battery's state. If the battery is weak or too cold, the car will quietly turn start-stop off. If yours has stopped working, a tired battery is a common cause.

When you replace it

• Replace it with the same type the car was built with, not a cheaper standard battery.
• Some vehicles need the new battery registered with the car's computer so it charges correctly.
• Tell the technician you have start-stop when you book so they arrive with the right battery.