This guide provides step-by-step instructions, with photos and videos, to help you replace the battery in a BMW yourself.
Table of Contents
On most 2002 and newer BMWs, you will need to register the battery, which is the last step in this guide. Do not skip battery registration or the battery will not last more than two years.
Common symptoms indicating that you need to replace a BMW battery:
Clicking sound when you turn the key
BMW won't start
The battery doesn't hold a charge.
High battery discharge warning on the instrument cluster
The engine struggles to turn over.
If your battery is less than five years old, try charging the battery first. Driving the car for at least 1 hour will charge the battery, or use a 12-volt smart trickle charger to charge it via your home's outlet port.
What You Will Need
Group 94R Battery (Stay as close as possible to the specs of the old battery specs. CCA, CA, AHr)
Follow these instructions to replace and register a BMW battery yourself:
Park your BMW. Turn off the ignition, remove the key but leave the vehicle unlocked. If you have an intelligent key, place it at least 30 feet away from the car.
Locate the battery. In most BMWs, the battery is in the trunk, while in a few older models, you will find the battery in the engine bay. Open the trunk and locate the BMW battery on the passenger side of the trunk floor. If you have a station wagon BMW, the battery is on the trunk floor. Remove the liner to expose the battery.
Use a 10mm wrench to disconnect the negative battery terminal. Rest the cable away from the negative battery terminal.
Disconnect the positive battery terminal. Next, disconnect and remove the positive battery cable. You will need to lift the red plastic cover to find the 10 mm nut you need to loosen up.
Remove the battery bracket. The battery is held in place with a bracket on the side and a top bracket. First, remove the top bracket by removing two 13 mm bolts indicated by the white arrows below.
Now it is time to remove the old battery. These batteries are heavy. Ask for help to lift the old battery.
Install the new battery. Carefully lower the new battery in place and make sure it is sitting correctly.
Secure battery. Reinstall the bracket. Do not overtighten them, or you will crack the battery housing. If you are installing a lead-acid battery, make sure to connect the vent hose. This is necessary so that gasses from the vent hole don't build up inside the trunk.
Clean the battery posts. Use a battery terminal brush to clean the battery clamps. Connect the battery terminals.
Connect the positive battery terminal first.
Connect the negative terminal last.
The last step is to register the battery with an OBD-II scan tool. You will need an OBD-II scanner that can register a BMW battery. Follow instructions on the scanner to register the battery.
The BMW battery registration process resets your vehicle's battery charging history. It deletes any stored battery and temperature statistics for the previous battery. Odometer reading won't be lost during the process.
When you replace a BMW battery but don't register the battery, your new battery may fail prematurely. In some cases, you may experience electrical issues or warnings on the instrument cluster.
Here are a few tips that will help you with the battery replacement process.
To save the memory functions on your BMW, you can use a trickle charger to keep the car powered up while changing the battery. You connect the backup power to the ground and positive terminals under the hood. These are the terminals used to you jump-start your BMW. When using a backup source, be extremely careful so that the positive terminal doesn't short to the ground or the body once you remove them from the battery. Cover the positive terminal with tape so that it doesn't accidentally touch any other metal body parts.
Always remove the key from the ignition and keep it released during the whole process.
If your BMW had an AGM battery installed at the factory, stick with an AGM battery type whenever possible. Another critical factor you need to consider is the battery capacity provided in ampere-hour or Ahr. If your BMW has a 90 Ahr battery, don't switch to a 60Ahr battery.
These specifications are necessary because if you change one of them, you will need to code your BMW so that your car knows how to charge the new battery. On top of that, you need to perform battery registration still. Battery registration deletes all the charge profiles of the old battery. If a previous owner installed the wrong battery, call your dealer and ask what battery your BMW requires.
Frequently Asked Questions
Which BMW models need battery programming?
The following BMWs need to have the battery programmed, also called battery registration.
2007 or latest X5 E70 chassis/platform
2006 or latest 3-Series E90/E91/E92/E93 chassis/platform
2005 or latest X5 E53 chassis/platform with the N62 engine
2004 or latest 5-Series E60/E61 chassis/platform
2003 or latest 6-Series E54/E63 chassis/platform
2002 or latest 7-Series E65/E66 chassis/platform
2008 or latest X6 E71 chassis/platform
This list is not all-inclusive. See the owner's manual or contact any BMW dealer to verify.
Can you install an aftermarket battery on a BMW?
The battery can be an aftermarket AGM battery. It doesn't have to be an OEM BMW battery, but it needs to meet the recommended specifications. It also needs to be coded and programmed so that the DME module knows how to charge it. While the battery type, capacity, and cranking amps can vary from the stock OEM battery, the battery size must be the same. For example, a couple of batteries that are in the same group size as the OEM BMW battery and are worth considering are:
Replacing the battery at a BMW dealership costs anywhere from $350 and $600. That includes parts and labour.
Replacing the battery yourself is straightforward, especially if you install a new battery with the same specs as the original. You can still change a BMW battery yourself, do it right, and still save money.
What is the best battery for BMW?
You don't need to cut corners and install the wrong battery size on your BMW. Many aftermarket batteries fit BMW and meet the specifications required by BMW. One crucial factor to consider besides the group size is the battery type. If your BMW battery has a white casing, it means it is a lead-acid battery. If the battery casing is black, it means it is an AGM battery.
Do I need to run battery registration if I disconnect the negative battery terminal?
If you need to disconnect the negative battery terminal to maintain your BMW, you don't need to complete battery registration upon reconnection. Assuming you reconnect to the same battery.
If I disconnect the negative battery terminal to perform tuneup, do I need to use the BMW scan tool to register the battery?
No, you do not need to register your old battery. The DME module has all the history of this battery and knows how to charge it. You will need to set the clock, synchronize windows, sunroof, and other memory functions.
I disconnected the battery and connected it a few minutes later. Now I have a warning light.
If you accidentally triggered a warning light, you will need to read the codes and clear them using a BMW scan tool.
What is the typical charging voltage on a BMW?
Typically a BMW alternator will charge the battery using 13 volts to 14.3 volts.
I get a charging malfunction when I start my BMW. What could it be?
Typically this is caused due to a bad alternator or a battery that may have a bad cell. Perform a charging system test. Parts stores such as Advance Auto Parts and Autozone will do this test for free.
Why is the yellow battery charging light coming on?
It could be on for various reasons, but most include a bad alternator, battery, voltage regulator, power module, etc.
I replaced the battery on my BMW, and now I have intermittent starting problems.
A loose battery terminal contact often causes this. Check and retighten or clean the battery cables that connect to the positive and negative battery terminals.
Can I change the battery capacity, e.g., from 90 Ahr to 110Ahr?
Yes. Make sure to perform coding to let the DME know you have installed a higher-capacity battery. You can also install a lower-capacity battery.
Can I change the battery type from Lead Acid to AGM?
Yes, you can. Make sure to code your BMW, so it knows the battery type has been changed. Perform battery registration as well.
Can I register a new BMW battery without a scan tool?
No. You will need a BMW scan tool such as Carly for BMW, Foxwell NT510, INAP, BMW Scanner, etc.
Why is my airbag warning light on after changing the battery on a BMW?
In some cases, you may notice that the airbag light is on after changing the battery. This is often caused by low voltage. You will need to use a scanner that can read BMW airbag codes. See what the codes are. If they are stored codes, delete them.
My BMW doesn't start. Can I read the codes with a scanner from Autozone or Advanced Auto Parts?
You can, but the OBD2 scanners used at Autozone and Advance are generic code readers and cannot read multiple BMW systems. You will need a scanner that can read BMW-specific codes.
Will AutoZone install a battery in a BMW?
We called two AutoZone's to ask if they would install a battery in a BMW, and in both cases, we were told no. That's not surprising, considering that you need to register the battery to do the job right, and AutoZone does not carry an OBD-II scanner that will register a BMW battery. You can still buy a BMW battery at AutoZone. Just keep in mind that you will have to install and register it yourself.
What are the signs of a bad BMW battery?
BMW engine struggles to turn over
The engine turns over a couple of times and stops.
Battery warning light on the dashboard
BMW dead in the morning, the car won't start
Battery Discharge Warning Message
The engine won't turn over; it just clicks.
I changed the battery. Now I have problems with lights, accessories, cluster, starting, etc.
If you are having problems after replacing the battery on a BMW, you may likely have had a short between the positive and negative terminals during the installation process. Check fuses first and scan for codes using a scanner that can read BMW-specific fault codes.
I don't have an IBS sensor; do I need to register my battery?
We can't say for sure. Most BMW models starting in 2002 need battery registration. Some models didn't require it up to 2005. Call your BMW and verify.
I replaced my BMW battery, but the new battery dies when the car is parked?
You have a current draw when the car is turned off. Learn more about a parasitic draw.