Doug Huffman. The ECU tracks a number of parameters of the battery to adjust the charging protocol to not damage the Absorbed Glass Mat battery. As the AGM ages and is used its allowable charging parameters change. Registration resets the histories. It ain’t what you don’t know that gets you into trouble. If the battery is good and the car is not charging, then the alternator or wiring is bad. With the car running, ask the mechnaic "what is the voltage across the battery?". - If is over 12V (should be something like 14 volts) then the alternator is charging. - If the voltage is low, the alternator is probably bad. The battery replacement cost is absolutely a sting compared to "the good old days," but then again I wasn't driving 130MPH on a track "back in the good old days." Definitely I won't be looking for workarounds to BMW engineering. Drives: 2010 BMW 335xi Coupe (AT) Join Date: Sep 2016. Location: Alexandria, VA. iTrader: ( 0) Got the key battery warning light ! Happened yesterday. Looks like I'll have to get out my soldering iron from what I've read online. Easy DIY battery replacement. Here I show how to replace the battery on BMW E90 series, probably applicable to several BMW models. I also show how to reset the battery in the the common steps is always disconnect pos (+) then neg (-) wires then reverse the order. So when the pos (+) is connected the car is not energized yet since the neg (-) is not connected yet. Been doing this on most of cars and never have any problems. 3) help to own other BMW as you are a loyal one to the brand. Most US Market E90 use the 90/720 AH/CCA battery. If you have CIC or the business radio with Bluetooth, you car uses the 90/720 battery. It also will have the Quote: Originally Posted by joe325i. Alright update: no blown fuses, but car START with ibs sensor unplugged from junction box on battery. $250ish part. Replace yourself, dealer will be more than double that. New ibs sensor has been redesigned. Get your battery registered thou so this doesnt happen again. App Vay Tiền.

bmw e90 battery replacement reset