If your battery is dead and you need to replace it, or you're just looking to swap for something lighter, head on over to your local dealership and find out what they charge for a replacement.
For me?
$195 for the battery, and
$231 for the installation.
$431+tax for a new battery!!! What??!?
Ok now that we've had our wtf moment, let's look at our options:
- Eat it. Bend over and fork over your hard-earned money. Or your not-so-hard-earned money... I'm looking at you, trust fund babies.
- Buy a battery and install it without coding, risk of fire/death/explosions are legit. Your call.
- Buy a battery from the dealership and install/code it yourself. Still pricey, but dat warranty tho.
- Buy a battery elsewhere that matches the OE specs, and install/code it yourself. Cheapest option for sure!
Personally, I'm going to run through option 3! I opted for a battery from the dealership because the price wasn't TOO ridiculous and it helps keep my warranty company from questioning any claims if I have all BMW equipment in the car.
Let's get started shall we?
NOTE: I will be using the Carly for BMW app, with an android device. This app has MANY features beyond what we'll use it for in this DIY, and in my opinion is well worth the cost. You can perform the same battery coding with other systems/software, feel free to shop around!
What you'll need:
- Socket wrench and extensions, also a socket screwdriver helps
- 10mm socket
- 13mm socket
- New Battery (range from $100-$200)
- Carly App for BMW PRO (~$60)
- Carly Adapter (the original Gen 1 will work for this, Gen 2 is more $ but has more features ~$50)
- Unlock the Carly battery Coding option (~$10)
Total:
$220-320 depending on battery choice, and about 15 mins of your time.
The bonus here is that you now have the Carly app, adapter, and all of it's abilities at your fingertips.
Since I already had the app, this only cost me $185 after my core charge for the battery.
Step 1:
Open your windows, doors, hood and trunk. This is just to prevent any chance of getting locked out of the car or not having access to something you need. Once that's done, open up the trunk and lift the tray cover that is over the battery. Use something to prop it up on the left hand side. Remove the bar over top of the battery, it uses a 10mm nut on each side.
To prevent the risk of electrical shock and/or death, disconnect the NEGATIVE line from the battery first. It uses a 10mm nut, do not fully remove the nut, just loosen it and pull the connection off and push it out of the way, hold it away with something non-conductive to make things easier.
Step 2:
To remove the positive connections, you'll be best off disconnecting the loom up top first. In the picture below, uncover and unscrew the two 13mm nuts circled in orange. The one toward the bottom of the image has a cable you can remove to make it easier to move things around. Then do the same for the one circled in blue (just loosen, don't fully remove). You'll also need to disconnect the vent thing that I am holding in the image, and is circled in green. Do not forget the vent thing.
Carefully remove the loom once everything is disconnected. Prop it off to the side and out of the way, doing the same with the positive terminal connection.
Step 3:
Remove the battery hold-down bracket on the side with the negative terminal, it uses a 10mm bolt and can be tricky to reach, this is the time to use the socket screwdriver if you have one, or some extra long extensions. Once that's out you can lift the battery up and out.
For kicks, I measured the voltage on both batteries, the old one came out of the car minutes after driving it, and was only reading 10.5v already.
The new battery was right on the nose at 12.4v and looking good! Note it's a slightly longer case, it still fits and this is apparently the standard size now for BMW.
Step 4:
Drop the new battery in, being careful not to pin any wires or the little vent thing. The bottom of the battery slides into a tab toward the front of the car, and the bracket holds down the side toward the back of the car. Getting that little bracket back in can be a PITA if you have big hands. A magnetic socket would be great here.
Reconnect the positive terminal and tighten down the 10mm nut, then place the loom back on top and reconnect the lower cable if you disconnected it earlier. Plug the vent thing back in the side of the battery case. Reconnect the negative terminal only once you've confirmed everything is properly connected and secure. The car should buzz back to life and you should see lights come on. If not, disconnect the negative and check your steps.
Step back and look at what you've accomplished all by your lonesome.
GOOD JOB. Beer time.
Ok now it's time to code in the new battery, Carly could not have made this easier.
Step 6:
Turn the ignition on without turning the car on, and plug the Carly OBDII adapter into the OBD port right next to your hood-release latch (has a small plastic cover). Turn on the bluetooth for your phone and pair the adapter. Open the app and hit connect, make sure you have a full connection and that the app says it identified the engine or it will not work. You may need to disconnect/connect a couple times to get a stable connection, the GenII adapter is better for this reason.
You should see "connected" on the bottom of the app home screen. Once connected, tap the "Battery" option.
You'll get this screen, if you haven't already purchased the battery registration option, do so now and then hit continue:
Read & scroll to the bottom of the warning, check the "Understood" box, and hit OK to continue:
Select your battery type, top option if no change to type/specs:
Hit "Register new battery now" once type is chosen or new battery info is entered:
Not much will change, but you're done! You'll see the text "New battery registered successfully" indicating you're finished. Close the app and shut down the car.
FINITO! You've just saved money, gotten access to some cool features of your car, and you'll save even more money next time or by helping a friend with your app!