If your car switches its engine off at the lights, it has a stop-start system, and that changes the battery it needs. Fitting a standard battery to a stop-start car is one of the most common reasons batteries fail early.
Why stop-start cars need a special battery
Every time the engine stops, the battery keeps the lights, screens and air-con running. Then it has to restart the engine, sometimes dozens of times on one trip. A standard battery isn’t built for that much work and wears out quickly.
What is an EFB battery?
An Enhanced Flooded Battery is a tougher version of a standard battery. It handles frequent restarts and recharges faster. EFB batteries are usually fitted to entry-level stop-start cars.
What is an AGM battery?
An Absorbent Glass Mat battery holds its acid in glass-fibre mats. It’s spill-proof, handles deep cycling well, and suits cars with lots of electronics or regenerative braking. AGM is common in premium and European cars.
AGM vs EFB at a glance
| EFB | AGM | |
|---|---|---|
| Built for | Entry-level stop-start | Premium stop-start and regenerative braking |
| Handles repeated restarts | Good | Excellent |
| Price | Mid range | Higher |
| Upgrade path | Can usually go up to AGM | Must stay AGM |
Does the new battery need registering?
Many modern cars, especially European ones, have a battery management system that adjusts charging to the battery’s age and type. When a new battery goes in, the car needs to be told. Skipping this step can shorten the new battery’s life. We register batteries on the spot when your car needs it.
Never downgrade. If your car came with an AGM battery, replace it with AGM. EFB can usually be upgraded to AGM, but not the other way around.
