What Happens If You Don't Register BMW Battery? And How to Do It?

Your 12V battery needs to work properly in the BMW, otherwise, on one bad day, you will not be able to start the car. In a BMW, you don't have many choices like push-starting or jump-starting to avoid damage. So, if your 12V battery is completely dead, you will have to spend some money.

Dead car battery replacement highlights

• Critical voltage:less than 10 volts
• Average battery age:4-5 years
• Tools needed:set of wrenches
• Timeneeded:15 minutes
• If done incorrectly:electronic glitches, frying ECU, no crank-no start
• DIY fix:possible
• How much to fix?$150 - $250

In short, you need to register the new 12V battery in a BMW to let the system know that the battery was replaced and now needs a little different pattern of charging. It means that the entire system of supplying electricity in your car will be readjusted to fit the new battery.

I want to tell you more about this process, so, let's dive in!

What happens when you register the new battery in the BMW vehicle?

Not all BMW cars need the new battery to be registered. But if we are talking about the vehicles that were made within the recent decade, they all need this procedure to be done. It doesn't mean that your car won't start if you don't register the battery, but the life of this battery will obviously be harder if you ignore this.

Here's what happens when you register the battery properly in your BMW:

• the control units are informed that the battery is new and that the voltage in the system may change;
• also, the units are adjusted to not overcharge the new battery because they will continue sending a lot of current to charge the battery as if it's old;
• the ECU will be adjusted to work in the new range of voltage and will not register any codes related to sudden changes;
• the battery will be treated properly from the very first time you start the engine in your BMW.

You may know that one of the most common reasons for the premature death of 12V batteries in cars is overcharging. When the battery gets too much charging, it may start melting inside. The power storage will become less efficient every single day and the battery will die much earlier than you expect it to die.

This is exactly the problem that is solved by coding the battery in a BMW car. Make sure you don't ignore this.

What happens when you don't register the battery in your BMW?

So, many people ask me if they can just replace the 12V battery in their BMW vehicles and driver without coding. The short answer is yes, you can do that. Your BMW will still start and will go, and it will most likely not even show any error codes and other problems.

But if you keep digging into this question, you will find out that the battery itself will suffer. It will be overcharged for some time until the ECU catches the changes and starts readjusting the charging system. This may take several weeks and for this time, the battery will most likely be worn out much more than it could.

Some batteries can't stand overcharging at all, so it's important to code the battery when you replace it just to make sure that your BMW treats it correctly from the very first engine start.

But yes, if you are stranded on the roadside and luckily have a shop with car parts and accessories nearby, you can just buy the new buttery, install it, start the engine, and go. The BMW won't try to stop you from that and the battery replacement won't cause any problems at all for the vehicle.

It's especially important to register the battery if it's different in size and type than the previous one. Otherwise, the battery may just be dead after a year of driving because of incorrect charging.

How to register the new battery in a BMW?

Unfortunately, BMW made this process pretty complicated. I've heard that one dealership charged $200 for battery replacement and coding and this is ridiculous. I've never owned BMW, so I can't check this and also BMW dealers rejected my requests when I asked them to tell me about the price of battery registration. So, if you know this, please let me know in the comments.

So, the process is simple in that case only if you have enough experience and also can rely on professional equipment. You will need a good BMW-compatible scanner and an understanding of how it works.

Then, the process is pretty simple:

• take the old battery off the vehicle (disconnect first minus then plus terminals);
• install the new battery (put first plus then minus terminals);
• don't turn on the engine, connect your OBD2 scanner to the port;
• use your scanner to find the option to register the battery;
• launch this function and wait till the process is completed;
• after that, disconnect the scanner, turn on the engine, and see if there are any errors.

This seemingly simple process is good for those cases when you have a BMW-compatible scanner that has all the needed software installed. If you are using the all-purpose scanner, it may have the wrong battery adjustment features and may need some programming.

I will not describe the more advanced programming in this article because it will take you too long to read but you can find guidelines on the internet. And still, it's better to get BMW software to adjust the battery settings.

What if I have warning lights after registering the battery?

Usually, you will not have any warning lights or error messages after you correctly register the new battery. If you do see one of them, it may not be connected with what you just did. Maybe, this warning light was there before but you just didn't notice it. Also, some problems may have happened just now and it's still not connected to the new battery.

One of the possible reasons is that the battery may not be of the needed type. In some BMW cars, this may trigger a warning light or some messages.

Here's what you should do if you see a warning light after registering the new battery in your BMW:

• pay attention to the light itself and find what it means in the manual for your vehicle or online;
• also, you may use the OBD2 scanner to read the code and then google the code to get more information;
• after that, you may also want to consult with a specialist to make sure you correctly understand the problem;
• if this is a minor problem that you can solve on your own, just do it;
• but in other cases, you may need to go to the dealership or to a trusted repair shop to have the issues fixed.

Very often, the warning light after registering the battery will tell you about the wrong parameters of the battery. So, when you buy the new 12V battery for your vehicle, make sure you are buying the right type. Pay attention to the voltage, amperage, and also battery capacity. Make sure the terminals are located similarly to the original battery that you have under the hood of your vehicle.

Of course, you should be very careful when connecting the battery. Some warning lights may go on because you connected the battery in the wrong order and now one of the electronic modules in your vehicle is fried. If this is the case, you will need some professional help.

Should you replace the battery in your BMW on your own?

Even though the process of battery replacement in the BMW vehicle may seem quite complicated, you can avoid paying a lot to the dealership. But you need to know for sure how to do it if you decide to replace the 12V battery on your own.

Make sure you follow the correct procedure when disconnecting and connecting the terminals. Also, remember that to register the new battery, you will need a scanner with BMW-compatible software. This is one of the most important things to have if you want to succeed in this. But you can also replace the battery and then go to the dealership to have it registered.

Can you drive your BMW if you didn't register the battery?

Yes, you can still drive after replacing the 12V battery even without registering it. The only problem is that your battery will most likely be overcharged. The vehicle will still readjust but this will take time and during this time the new battery will get some damage.

But if you are stuck in the middle of nowhere because of the dead battery and happen to have another 12V battery, you can replace it and still start the car and go. Of course, you better go to the nearest BMW repair shop if you want to prolong the life of the new 12V battery in your vehicle.