How do start stop systems work?

Basic Start Stop systems work by shutting off the engine whilst the vehicle is stationary. When the brake pedal is released or the accelerator depressed, the engine quickly restarts enabling the vehicle to be driven. In more advance Start Stop systems, the vehicle may also incorporate regenerative braking or engine power assistance technology. This technology has the ability to switch off the engine when the vehicle is coasting or braking as well as when stationary. Shutting off the engine eliminates the amount of fuel that would otherwise have been used, reducing both vehicle emissions and fuel consumption

What does this mean for the Battery?

In heavy traffic, the battery in a start-stop vehicle may have to start the engine several times in a matter of minutes. Meanwhile, the battery must also continue to power the vehicle's electronics, even when the engine isn't running. Manufacturers of start-stop and similarly demanding hybrid vehicles have turned to newer battery technologies – the Absorbent Glass Mat (AGM) battery and Enhanced Flooded Battery (EFB).

Battery Replacement

When replacing the battery in a start-stop vehicle, ensure that the battery used is a like for like replacement. Only replace EFB with EFB and AGM with AGM Start Stop compatible batteries. Avoid fitting a conventional battery in a vehicle with Start Stop technology as this may damage the vehicles electrical system and lead to premature battery failure. In Start Stop vehicles the battery is vital to maximising the environmental benefits of these technologies. Battery replacement in Start Stop vehicles should be conducted in conjunction with a compatible Battery Management System (BMS) or Intelligent Battery Sensor (IBS). This ensures that all relevant sensors and electrical components are reset and subjected to a ‘memory test’ which ensures compatibility of the replacement battery.