BMW F30 BATTERY SPECS (as of August 2022)
Size: Group 49
Type: AGM
Amp Hours: 92ah
Cold Cranking Amps: 850CCA
BMW Part #: 61 21 5 A40
TOOLS REQUIRED
-10mm socket
-13mm socket
-socket extension
-Carly adapter (or any software that can register a BMW battery)
For the past month, my car has been struggling to start up. I took it to Auto Zone to have the battery tested and they confirmed that it needed to be replaced. We go inside and their computer system shows a handful of batteries that they recommend for my car.
But when we walked over to the shelf, the specifications printed on the top of the battery didn’t match the battery in my car, so you have to be careful. The stock battery in my F30 was 90 amp hours, but the highest rated one they sold was only 80 amp hours.
I thanked them for the help, but decided to look online instead. A search of the battery part number didn’t return any results, and a deep dive on the forums revealed that the battery in my car had been discontinued. I spent over an hour online trying to find something with similar specs and there were hardly any options, at least that could be shipped to me.
I called my closest dealer and it turned out that a Genuine BMW battery was only $276, which isn’t much more than the batteries at Auto Zone. So save yourself the time and headache and buy it from the dealership. Buying a generic isn’t a huge savings and you’ll likely be settling for lesser specs.
INSTALLATION
Like most BMW’s the F30’s battery is located in the trunk on the right hand side.
Remove two 10mm screws to remove the retaining bracket.
Loosen the 10mm nut to remove the negative battery cable from the terminal.
Loosen the 10mm nut on the positive battery cable and move it aside.
Detach the vent hose from the positive side of the battery.
There’s a 10mm screw at the base of the battery on the negative side. You may need a long extension to reach it.
I put some masking tape on the negative battery cable to get it out of the way during removal and re-installation.
The battery is heavy, 53 pounds (24kg) to be exact. And it’s in an awkward place where you don’t have a lot of leverage. If you have neck or back problems, you might want to think twice about this install.
Put this new battery in, in the same orientation. The negative terminal should be closest to the rear of the car.
Secure the 10mm screw at the base of the battery and reinstall the retaining bracket. Install the negative, then the positive cables. The torque spec is 10 newton meters on each, but I won’t tell anyone if you tighten them up by hand. Install the vent hose which allows gasses from the battery to escape outside the vehicle.
REGISTRATION
With the battery installed, we need to register it to the car. BMW’s from the mid 2000’s onward use an algorithm to keep track of the battery’s age, and the car adjusts how much the battery charges over time. Whenever you install a new battery, you must register it to the car which resets the battery charging statistics. Failure to do so will result in overcharging of your new battery.
There are a handful of tools that will allow you to do this at home. I’m using Carly, but BimmerLink will work too.
Because the Genuine BMW battery is nearly the same specs as the one I’m replacing, we don’t need to do any additional coding. However, if you happen to buy one that its 80amp hours instead of 90, you’ll need to code that first before registering.
Just a note, the original battery was 90 amp hours and the new battery is 92. According to the parts guy at the dealership, it’s close enough that I don’t need to change anything.
Once you’ve connected your car to the Carly app you’re ready to register it. Tap “Features” in the lower right corner, then choose “Battery Reset” from the menu. Choose the option that says “Register Same Battery.” Carly will read your current battery info, then give you the option to register your new battery. The whole process takes about a minute.
BATTERY MAINTENANCE
If you don’t drive your BMW everyday, its crucial to use a smart charger like this CTEK MXS 5.0 to keep the battery topped off when you aren’t driving. I didn’t have one the first year I owned this car, and I think letting the battery discharge that first winter caused irreversible damage.
So whether you work from home, or maybe you don’t drive your BMW at all in the winter, you need to make sure you are maintaining your battery in order to get the maximum life out of it. These modern BMW’s are very power hungry, even when they’re just sitting.
INSTALLATION VIDEO
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