Moving between these two types without coding can lead to over-charging or under-charging.Īlso, batteries have a discharge rating called amp hours (ah). However, if you switch from a wet-cell type battery to an AGM type battery, or vice versa, you must code for the change.ĪGM and wet-cell batteries require a different rate of charge output from the alternator. You may not have to! That is, so long as you replace your old battery with an exact replacement. Q: Why do I need to “code” for a new battery?Ī: The answer to this varies. This would be accompanied by a check control warning of excessive battery discharge.” Also, when the IBS sees that battery voltage is too low for normal vehicle operation it can start shutting down vehicle functions to conserve power while keeping the vehicle operational.

The registration process takes place in the ECU, which is the main player in this system. Therefore, at battery replacement time, if you don’t tell the ECU it has a new battery it will overcharge the new battery causing it to wear out faster. The IBS reads this and the ECU tells the charging system to increase voltage and amperage output incrementally as the battery matures. A battery deteriorates normally over time and depending upon service demands and driving profile. The ECU uses this information to control how much charging voltage is needed from the alternator to support vehicle electricity needs.

The IBS measures the state of battery charge and sends this information to the ECU. The long answer: “The negative battery cable has an electronic control unit on the battery end of it called an intelligent battery sensor (IBS). Registering a new battery resets the algorithm back to optimal charging voltage for the specified battery. Q: Why do I need to register a new battery?Ī: The short answer is that BMW designed the charging system with an algorithm that varies the rate of charge by the age and type of the battery installed. Over time, improper charging may have detrimental effects on the lifespan of your cars battery and the operation of the vehicles electronics. Q: I replaced my battery and it works just fine, why all the fuss?Ī: Disregarding the need to register and code for a new battery may result in improper charging. Registration and coding will not be successful on older vehicles that are equipped with basic power management systems. Read me firstly: if you have an older E90, this doesn’t apply to you, this guide only applies to vehicles equipped with IBS (intelligent battery sensor).

Topic: Reading if you’d like to know why it’s important to register and code a new BMW battery, and how you can get it done yourself!

Ncs expert battery registration