Battery replacement BMW e65 745i, 745Li, 750i, 750Li, 760Li, 730D, 740D, 730i, 735LI, common mistakes

Applies to any BMW with power module:

e90, e60, e70, F01, F02, F30 etc

So you got a “recharge battery’ warning, and you went to AutoZone or any other store and bought new battery. You installed it, then you probably were told to register it, or some mechanic registered it for you.

You think everything is good now, right?? But battery warning still comes back and some smart mechanic or independent shop tells you its okay as long as battery is new and registered!

So here is the story:

One 2003 BMW 745li with very low miles came over with ABS module errors and with battery discharge warning. Well, he replaced the battery and it was “professionally registered”. But not only problems still there, but now it actually creates lots of faults on the top! Plus his alternator seized! Coincidence?? So lets see:

BMW e65 before 2004 were equipped with 110ah standard lead acid battery.

After 2004 they introduced new standard, which is 90ah AGM battery (which is great battery if maintained well).

So not only type is different, but capacity is lower!!!

What happens when today you buy 90AGM battery (they don’t sell older 110ah battery for these cars) and install it into the vehicle which has highly sophisticated power module, which knows battery type and capacity??

Quite simple:

it will still think you have 110ah lead acid old battery and it will constantly try to charge it to get it to fully charged state!!! And it will not ever happen, but will destroy your new battery and will put lots of stress on alternator plus you might get various faults in different modules!

OLD 110ah LEAD ACID BATTERY setting:

CBS_SCEN_10H
    nicht_aktiv
CC_15_EIN
    wert_01
BATTERIE_KAPAZITAET
    110ah
ERKENNE_SBE1_HI_RE

NEW 90AGM SETTING

BATTERIE_KAPAZITAET
    90ah
ERKENNE_SBE1_HI_RE

or you can use BMW progman, which will do it automatically, but i prefer NCS instead: quick&easy&safe

That’s why BMW dealership will charge you more to reprogram your vehicle so it supports new battery type. This is what lots of mechanics and shops don’t know about or simply ignore it!!! Why?? because they don’t want to learn anything and interested in quick and easy money.

So basically you are supposed to check what power module says, but if your car is 2004+, most likely it came with 90AGM and all you need to do is to register it. There are few options here:

BMW INPA, ISTA, aftermarket tools can run it too, but only NCSEXPERT or PROGMAN can reprogram power module so it supports 90AGM.

AND YES YOU HAVE TO REGISTER NEW BATTERY, BECAUSE POWER MODULE CONSTANTLY CHECKS THE BATTTERY CAPACITY AND WITH AGE, BATTERY GETS WEAKER AND THEREFORE IT APPLIES LESS CURRENT TO FULLY CHARGE IT. SO NOT REGISTERING NEW BATTERY WILL MAKE POWER MODULE THINK, YOU HAVE STILL OLD WEAK BATTERY AND IT WILL NOT TRY TO FULLY CHARGE IT (I’M NOT GOING DEEPLY INTO DIFFERENT SPECS IT CHECKS AND RUNS WHILE YOU DRIVING YOUR CAR), BUT BOTTOM LINE YOU HAVE TO REGISTER IT AND IF YOUR CAR IS OLDER MODEL, YOU AVE TO MAKE SURE POWER MODULE ACCEPTS 90AGM.

8 thoughts on “Battery replacement BMW e65 745i, 745Li, 750i, 750Li, 760Li, 730D, 740D, 730i, 735LI, common mistakes

  1. Cecil Mitchell

    Wow you are talking about everything that is wrong with my car.I have a 2002 745 Li and everything I read on this website is everything that’s wrong with my car, smokin tailpipes,the battery, the fault codes…it just goes on and on. that’s just crazy the2002 BMW7 s are very predictable. So sad to spend this much money on a vehicle in the beginning for it all to come down to the same problems somebody should have done their homework first!!!

    Reply
  2. Snief

    I have a 2005 745li BMW that came with a Agm battery. I just replaced it the other day with another Agm. Should I just register the battery with INPA or do I have to reprogram the power module to accept Agm? Since I’m not sure if the setting was on Agm in the first place ?

    Reply

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