[WE90325]

I have had my 06 325i since new. It only has 18K miles. The warranty is over. The car gets parked for weeks with no starting issues. About 2 days ago I tried to start the car and it could barely crank but still got it started. After this noticng that the battery was weak I hooked up a 2A battery tender. After 3 days the car will not start. hooked it up to a 25A battery charger (while still in the car and connected) for about 8 hours and still would not start. Jump started the car and then drove it for about 20 miles keeping the revs up, while driving the radio would not have any volume to it and the brake light and ABS warning lights keep going on. When I got home I chyeck the brake fluid and the level is okay. Tried to start the car again and it is completely drained.

Called the BMW dealer on Guam and asked about this and they said the battery is dead. if i replaced the battery it would have to be the original one ($367) because the computer needs to know what battery it is and they also need to program the computer as to the charging rate it needs to be at. I can buy an replacement battery (Interstate) for $135.

I have an 04 Subaru STI with 16K miles on original battery a Mitsubishi Evolution with 46K miles just replaced the battery last year and never had this problems or things that needed to be done just to replace the battery.

I was also told that I should not disconnect the battery from the car or else I will need to take it to the dealer to reprogram, too late I already took it out to try and re-charge the battery.

I can see it coming I cannot compare a BMW to a Japanese car but why make this a complicated thing?


Any comments or suggestions? I think getting a $367 battery plus reprogramminng is crazy.

Does anybody have an idea what the specifications are for the OEM battery?

 

[Dirty_Tool]

You can buy a battery with identical specs however it still needs to be registered in to the vehicle's electrical system. Unlike other cars the later model BMW's have a power management system which records battery state of charge, temp, trips, stationary periods, etc. After replacing a battery all of this info needs to be reset in the power management system and the battery replacement registered. If this does not happen then the system is working off of inaccurate data which can cause problems one of them being possible premature failure of the new battery. As far as exactly what exact aftermarket battery could you use I can not help you there.

 

[WE90325]

After reading about this system and not seeing what advantage it brings. I hesitantly took my car to the dealer to replace the batterya and whatever they need to do it is a whopping $400 +. Why could they not just leave the charging system alone as well as the dip stick. This kind of charging system did not extend the life of the battery in anyway? like what I said my Subie has an ordinary charging system, yet the battery has lasted more than 5 years. the Bimmer 3 years and 8 months.

This things are so simple and efficient.

 

[Dirty_Tool]

There is a lot more going on in your BMW than your subaru. With the advanced electronic systems and the Fiber optic Bus system this power management system is a necessary evil. Without it your battery would not have lasted as long as it did. Im not siding with BMW as I do think there is room for improvement but I did want to point these things out.
Best,

 

[WE90325]

I agree the Subie is not that complicated, do we really need all this technology? It is another attempt at keeping the car with the dealer just for simple things, like TPMS, Smart keys, etc.

If they did it right you could just replace any battery and the system is smart enough to adapt to what it has up to certain parameters.

Anyway thanks just my 0.02 cents.

 

[Dirty_Tool]

I kind of agree that they should allow the battery registration to be done via the I drive or instrument cluster so that you're not forced to go to the dealer for just a simple battery replacement. That would make more sense.

 

[WE90325]

I kind of agree that they should allow the battery registration to be done via the I drive or instrument cluster so that you're not forced to go to the dealer for just a simple battery replacement. That would make more sense.

I agree, very well said. I worked for a dealership as a manager and I could see this coming slowly trying to get the cars back to the delaership for very simple reasons + $$$$

I am now more appreciative of the simple things that my Evo and Subaru have. This 2 cars are in between my 1972 Mini and the Bimmer in technology. The Mini is too outdated to use everyday it just for Sunday drives.