Quote:
Originally Posted by jcattletown
Hello, bNks334, I have a question for you. In the following paragraph, you said that ECU will determine the voltage of charging needed based on the information from IBS. For a new battery, the IBS should be able to sense the high voltage so the ECU will reduce the charging voltage accordingly. If it works this way, is registering a new battery needed? Just my thought. Also, the link you provided to download BMWtool, https://spool [Delete this] stre...uide-setup.13/, is not working. Could you clarify that? Thanks a bunch.
"The long answer: "The negative battery cable has an electronic control unit on the battery end of it called an intelligent battery sensor (IBS). The IBS measures the state of battery charge and sends this information to the ECU. The ECU uses this information to control how much charging voltage is needed from the alternator to support vehicle electricity needs. A battery deteriorates normally over time and depending upon service demands and driving profile. The IBS reads this and the ECU tells the charging system to increase voltage and amperage output incrementally as the battery matures. 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. |
A lot of the guide is paraphrased from various sources.
The fact of the matter is that there is a charging algorithm that varies alternator output based on the calculated age and charging state of your battery. Registering a new battery resets this algorithm and the "age" calculation. If you don't re-register the new battery the dme will base the charging profile off the age of your old battery...