Registering a new battery with the on-board computer: why and which cars

Registration means telling the car that the battery is new. Other words for it are battery coding, programming or adaptation. A modern car has a battery management system (BMS). That is the part of the on-board computer that monitors the battery and decides how much and how hard the alternator charges it. The BMS takes the type and the capacity of the battery into account.

If you fit a new battery without registering it, the BMS thinks the old battery is still in place. Varta writes that the BMS cannot use the right charging strategy if the technology or the capacity of the battery has not been entered correctly, or if the battery is not recognised as new.

The Bosch technical information on battery replacement states that the replacement must be reported with the diagnostic tester, after which the battery management system is reset.

Many modern cars, especially cars with start-stop and a battery sensor. According to the ANWB, a modern car’s battery must be registered in the energy management system after replacement. In its technical information, Bosch mentions BMW, Volkswagen, Audi, Peugeot and Fiat.

Not every car needs it. Bosch writes that a car without this option learns the battery by itself while driving, if needed. Whether your car needs registration depends on the make, the model and the year. We look it up based on your registration number (kenteken).

You can find a clue yourself under the bonnet or in the boot: a small box with a plug on the negative terminal of the battery. That is the battery sensor that feeds the BMS with data. If your car has such a sensor, it has a battery management system and registration is often needed. You only know for sure after looking it up by registration number or in the owner’s manual.

Sources: ANWB, Bosch (technical information on battery replacement, February 2021) and Varta.

The car usually keeps running, but the battery is not charged in the right way. You do not notice that straight away. The consequences according to the manufacturers:

If your start-stop has stopped working since the new battery, also read start-stop system not working: what does it mean?

Yes. During registration the mechanic enters the type and the capacity. If the battery does not suit the car, registration does not help. Bosch gives these rules:

According to Varta, switching from EFB to AGM can be sensible. We fit the same type, or the type the manufacturer allows. You can read more about AGM, EFB and how long a battery lasts in our car battery replacement guide.

On many modern cars you cannot. The ANWB writes that on many modern cars the battery must be learned again and that you cannot do this yourself. It requires diagnostic equipment that can communicate with the on-board computer of your make.

Registration can be done at the dealer, and also at an independent garage with the right equipment. Have you already fitted the battery yourself, and is the start-stop no longer working or is a warning showing? Then have the car read out. The battery can still be registered afterwards.

We first test whether it really is the battery. After that it works like this:

1. Testing: we test the battery, the charging system and the starter motor. That way we only replace what is needed.
2. Looking it up: based on your registration number we look up the right type and capacity, and whether your car needs registration.
3. Replacement: we fit a battery that suits your car, AGM or EFB with start-stop.
4. Registration: with our diagnostic equipment we register the battery with the on-board computer if your car requires that.
5. Checking: we read out the car and check that no warnings remain.
6. Disposal: we dispose of the old battery.

We tell you the price in advance, as one amount based on your registration number, and we only replace parts with your approval. You can read more about how we work on our page about car battery testing in Rotterdam.

We prefer to supply the battery ourselves. That way we know it suits your car and its start-stop system, and we sort it out if anything is wrong with the battery. If you already have a battery, call us with your registration number and we will tell you what we can do for you.

Yes. On modern BMWs it does. Bosch names BMW as a make where the replacement is reported with the diagnostic tester. The energy management there takes the capacity of the battery into account.

According to the ANWB, the learning process is complete when the start-stop, the climate control, the rear window heater and the electric power steering work normally again. If the start-stop stays off, the battery may not have been registered properly, according to Varta.

Yes. Some cars can. Bosch writes that a car without a registration option learns the battery by itself while driving, if needed. Cars that require registration need diagnostic equipment.

No. Bosch gives this rule: replace an AGM with an AGM. According to Varta, switching from EFB to AGM can be sensible. We fit the same type, or the type the manufacturer allows.

No. Bosch advises choosing the capacity closest to the specification. According to Bosch, a battery that is too large is not fully charged and starts to sulphate. A battery that is too small is overcharged.

There is no public market price for it. We look up whether your car needs registration based on your registration number. We tell you in advance what the battery and the registration cost together.

• ANWB: Hoe werkt een accu en wanneer moet je je accu vervangen? (how a battery works and when to replace it, in Dutch)
• Bosch: Technische informatie: Bosch-accu vervangen (technical information on battery replacement, February 2021, in Dutch)
• Varta: Start-stop does not work
• Varta: Start-stop battery replacement