AGM vs EFB vs flooded battery — which to choose?

Not every battery suits every car. Besides capacity and starting current, the construction type matters: flooded, EFB or AGM. The choice isn’t a matter of taste — in modern cars it’s a requirement.

Flooded (SLI) — the classic

The traditional lead-acid flooded battery works well in older cars without extensive electronics and without a start-stop system. It’s the cheapest, but copes worse with deep discharges and frequent cycles.

EFB — reinforced for light start-stop

EFB is an improved version of the flooded battery, more resistant to charge and discharge cycles. It’s used in cars with a basic start-stop system.

AGM — for demanding start-stop and regeneration

AGM is the most advanced type: the electrolyte is held in a glass-fibre mat. It withstands very frequent cycles, deeper discharges and heavy loads, which is why cars with extensive start-stop and braking energy recovery require it.

• Flooded — older cars without start-stop, cheapest
• EFB — cars with a basic start-stop system
• AGM — extensive start-stop, regeneration, heavy loads
• The rule: you can go “up” (EFB→AGM), not “down”

In a start-stop car don’t skimp on the battery type — an ordinary flooded one will fail quickly, and the car may not register the change.

Not just the type — also selection and registration

Besides the type, the right capacity, starting current and dimensions matter, and in start-stop cars registering the new battery in the computer is often necessary.

We’ll select the right battery type for your car and replace it with call-out.