DIY Battery Replacement

[Marc08EX]

I never thought that replacing a battery could be so complicated. BMW: why do you have to make the battery system so complicated!

When my car died last week, I thought I could just replace the battery with whatever's available in an auto parts store. Then I found out that there are different types, Ah, CCA's, etc. I also found out that each car from the exact same model and exact same model year could have different batteries!!! I was literally doing this --> So it's best to stick with whatever battery specs you have installed in your car unless you are planning to code it.

I tried searching the forum on how to replace the battery but I didn't find any. For some, this process might be simple but I just wanted to help out anybody who's intimidated by changing the battery because of the system complications and how much stuff the battery has on top of it.

On to the DIY...

First check your battery specs. I have a lead-acid battery with 80Ah and 640CCA. Like I said earlier, try to keep the specs the same as your old battery unless you're planning to code it. My old battery's part number is 61 21 7 604 815. Jason @ Tischer helped me out a lot and he said that this battery is obsolete and that the new replacement part number is 61 21 2 353 808. If your current battery has different specs, ask Jason or your local dealer what your replacement part number is. Unfortunately, batteries can't be shipped out because it's considered hazardous material so you have to buy this from your local dealer if you choose to stick with OEM.

Here's a list of tools you'll need:

• Rachet
• Rachet Extension
• 10mm socket
• Screw Driver

*** Please ignore the 13mm socket. From other videos I watched, they said you needed a 13mm. I didn't use it anywhere.

Your battery is located in the trunk. Pop the trunk and pop the carpet in order to expose the battery. Here's what you'll see:


*** Image taken from the web because my image came out blurry...

First step is to remove the 2 10mm nuts holding that black curved bracket.



Once you have this bracket removed, you'll now have access to the entire battery as shown:



Second step is to remove the battery's negative terminal using your 10mm socket and rachet. You don't need to completely remove the nut. Just loosen it enough to be able to remove the terminal.



Once you have the negative terminal removed, set it aside so that you don't accidentally hit it with anything.

Next step is to remove the battery's positive terminal along with that big red box on top of the battery. Flip up the cover as shown below to expose the positive terminal of the battery.



Again, use your 10mm socket and rachet to loosen this nut. You don't have to remove it. If your rachet is all metal like mine, make sure you don't hit any metal part of your car or it will cause a big short.

After loosening the positive terminal's nut, you now have to release the clips holding the big red power box to the sides of the battery. This is where your screw driver comes in. There are clips on either side and you just position your screw driver as shown below and pop them out.



After releasing the 2 metal holders, your entire red power box should come loose.



Next, remove the vent tube on the side of the battery near the positive terminal.



Next step is removing the metal plate near the negative terminal that holds the battery down to the car. In my case, there was just a bolt towards the bottom of the car. On other cars, there's a long bolt that goes all the way up to the same height as the terminals. So for my case, I needed to use an extension.



You can also see that there are 2 other holes near that plate. That's for accomodating different size batteries to your car.

Once all these steps are done, you are now ready to remove your battery. Just move everything to the side as much as you can and lift up your battery and out of the car. Please be careful as the battery is heavy.

Here's a comparison picture of my old battery and the new battery. As you can see, the size is different between the two.



Pop the new battery in place. Towards the front of the car, make sure that the lip at the bottom of the battery goes underneath the holder as shown below:



While you're at this step, connect back the vent tube to the battery as well.

Next step is to re-install the metal bracket beside the negative terminal that holds your battery in place. As you remember, the new battery is wider than the original battery and as a result, I had to use a different screw hole to install the holder.



After this, your battery should be bolted down to the floor securely and it shouldn't move. Give the battery a few tugs just to make sure it doesn't go anywhere.

Re-install the red terminal to the positive node of the battery. Tighten the screw down using your 10mm socket and rachet. Re-secure the metal tabs on either side of the battery as well. You should hear a clicking sound. Once these are done, the big red power box shouldn't move at all.



Re-install the negative terminal to the negative node of the battery and tighten the 10mm nut down. Mine sparked a little when I connected the terminal to the battery's negative node.

After, re-install the curved metal brace on top of the battery and secure it with the 2 10mm nuts.

Once you're done, you have to register your battery to the car. There are certain tools that do this. Or you can bring your car to an independent shop or dealer to have your battery registered.

Hope this helps out my fellow 1 series owners!

***DISCLAIMER: I will not be responsible for anything that happens to you or to your car when you perform this DIY. This is an article to help out fellow forum members on how to replace the battery. If you are uncomfortable doing this, bring your car to an independent shop or to the dealer and have them perform the work.***

[nacaruh]

Nice guide! I just did mine the other day (and coded)!
Very simple to do, and fyi, you do NOT have to use a "BMW" approved battery. That is totally up to you! The only difference you would need to worry about is the AGM and non AGM type when it comes to registering it. I had the stock non-AGM, 720CC 160RC (original battery), and I replaced it with a Duralast Gold Battery (H8-DLG, 760CCA 150RC) from Autozone. It costed me $140.

[Marc08EX]

Originally Posted by royallecaf

Nice guide! I just did mine the other day (and coded)!
Very simple to do, and fyi, you do NOT have to use a "BMW" approved battery. That is totally up to you! The only difference you would need to worry about is the AGM and non AGM type when it comes to registering it. I had the stock non-AGM, 720CC 160RC, and I replaced it with a Duralast Gold Battery (H8-DLG, 900CCA 150RC) from Autozone. It costed me $140.

Can the CCA's be different?

[nacaruh]

Originally Posted by Marc08EX

Can the CCA's be different?

Yes, from what I found out, the CCA can be exact as the previous one, and it doesn't hurt to have a higher one. And your RC can be anywhere "close" to your stock battery's RC. Regardless if it was the same spec battery or not, I would have still registered my battery to the car.

[Marc08EX]

Originally Posted by royallecaf

Yes, from what I found out, the CCA can be exact as the previous one, and it doesn't hurt to have a higher one. And your RC can be anywhere "close" to your stock battery's RC. Regardless if it was the same spec battery or not, I would have still registered my battery to the car.

What tool did you use to register it?

The employee from the registering tool manufacturer I talked to said you should stick to the same specs for everything especially the battery type.... That's why I didn't go through Autozone and went OEM. I wanted Autozone batteries first because of the warranty and the cheaper price point.

[nacaruh]

Originally Posted by Marc08EX

What tool did you use to register it?

The employee from the registering tool manufacturer I talked to said you should stick to the same specs for everything especially the battery type.... That's why I didn't go through Autozone and went OEM. I wanted Autozone batteries first because of the warranty and the cheaper price point.

I used a K+DCAN OBD cable w/ INPA (latest version).
I believe if you change type of battery (AGM/non), you have to also use NCSEXPERT.

[bmw1racer]

Originally Posted by royallecaf

I used a K+DCAN OBD cable w/ INPA (latest version).
I believe if you change type of battery (AGM/non), you have to also use NCSEXPERT.

You can also register the battery using BMWhat... And from what I've read, it's pretty easy to do.

BTW, very good, DIY, Marc.

[Marc08EX]

Just got my battery registered. WOOT!

Originally Posted by bmw1racer

BTW, very good, DIY, Marc.

Thanks for the compliments bud!

[bmw1racer]

Originally Posted by Marc08EX

Just got my battery registered. WOOT!

So what tool/app did you use?

[Marc08EX]

Originally Posted by bmw1racer

So what tool/app did you use?

AutoEnginuity.

[bmw1racer]

Originally Posted by Marc08EX

AutoEnginuity.

Cool.

I'm going to bookmark this DIY for my next battery replacement, which hopefully will be a lot longer than 2-1/2 years...

[baja2700]

not sure if this is in another thread but is it possible to swap stock battery out for an optima or another type of lighter weight battery? sorry in advanced if there is a thread for this already!

[Marc08EX]

Originally Posted by baja2700

not sure if this is in another thread but is it possible to swap stock battery out for an optima or another type of lighter weight battery? sorry in advanced if there is a thread for this already!

From my research, you can. Just make sure that it's the proper size and it has a lip on either end so that it can be held down by the metal bracket. Also, if you're going to change the battery type to AGM, you need to get your car coded.

[02rsxpilot]

Originally Posted by baja2700

not sure if this is in another thread but is it possible to swap stock battery out for an optima or another type of lighter weight battery? sorry in advanced if there is a thread for this already!

HPA sells a kit for mounting a lightweight battery. You can get the kit and battery from them for a shade under $400. Saves ~30 lbs. compared to stock.

[baja2700]

Originally Posted by 02rsxpilot

HPA sells a kit for mounting a lightweight battery. You can get the kit and battery from them for a shade under $400. Saves ~30 lbs. compared to stock.

awesome!! thanks guys! looks like ill be spending another 400 clams

[GuamX1]

I have the cable usb to obdII where do you get the software to code the battery?

[Timmy42]

A useful tip for everyone:

The metal hold-down bracket is really tricky to get fastened down when you are installing the new battery. The solution that I found is to just barely tighten the bracket's bolt before placing the battery. This makes the bracket easy to move around. Then, use a straightened out metal coat hanger to adjust the bracket position as you move the battery into place. The coat hanger solves the problem of not being able to squeeze your hand down there to align things.

[1seriesfan]

Thank you, thank you. I just replaced my battery in my 2011 (Group H8). Bought it at WalMart ($130 w/tax) because I live in a rural area and this was the closest and by far the cheapest. From my days in the auto parts business, I think all batteries were made by one or two manufacturers anyway, this is likely an Exide battery. Anyhow, it FIT LIKE A GLOVE and I registered it with my Carly adapter, all done in just minutes. Thanks to your pics and instructions, PIECE OF CAKE and saved a TON of money!!

[OneTwenty8i]

If I replace my current battery to one with the same specs, will it still have to be coded and registered?

[Eagle01]

Originally Posted by iamhnry

Nice guide! I just did mine the other day (and coded)!
Very simple to do, and fyi, you do NOT have to use a "BMW" approved battery. That is totally up to you! The only difference you would need to worry about is the AGM and non AGM type when it comes to registering it. I had the stock non-AGM, 720CC 160RC (original battery), and I replaced it with a Duralast Gold Battery (H8-DLG, 760CCA 150RC) from Autozone. It costed me $140.

Do you have the steps of dyi coding of the new battery with the car ?

[iminhell1]

Originally Posted by Eagle01

Do you have the steps of dyi coding of the new battery with the car ?

www.1addicts.com/forums/showthread.php?t=1338304

[Zombie_Head]

I am looking for a new battery and i have a question.

Currently the car has a BMW AGM 70ah 760a battery.

Should i get the exact same one? or should i go for 80ah 800a unit?