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Replacing the Battery

3K views 19 replies 12 participants last post by  LOS 
#1 ·
My 318is has a dead battery. Jumping it gets it started just fine, but it won't start on it's own (I think pretty old) battery, so I'm going to get a new one and install it myself. Anything special to know first? My stereo is aftermarket and doesn't have any code to enter, so that's not a problem. Just take the old one out and slap in the new one and I'm good to go? Thanks a lot!
 
#2 ·
Yep, be sure to get the same size battery or you may run into issues, make sure the terminals are close to where the old ones are and are on the same face of the battery as before (IE: if it's on the top, dont get a battery with terminals on the side)

Your computer may complain once you turn on the car the next time.
You may want to get a yellowtop battery if you want an upgrade or have some powerful amps, otherwise, a standard lead acid will work just fine.


If you are really worried, I'd wait for another person to chime in since I havn't really done this for myself yet, I do have a stock radio and I DONT have the code... so I'm holding off untill I REALLY need a new one.
 
#3 ·
Agreed. Optima Yellowtop is a good choice if you have a serious system. Otherwise, the dealer is probably the best place to get the battery. Its expensive, but worth it.
 
#6 ·
I changed my battery when I bought my car, I went to the dealer and got the stock battery. I had some problems with it b/c the original owner had installed a non-stock battery, which had smaller terminals than the BMW battery. He tightened the connectors on his battery so tight that they're bent too small for the stock battery. I tried to bend them back but it was hard, so every so often the connector comes loose and I can't start my car until I fiddle with the connecton (which also sets off the alarm :pissed2)

other than that, I had no problems swapping batteries, i have an after market alpine head unit. i'd sugguest you make sure the terminals on your new battery are the same size as your old ones. (and i thought they were all the same)
 
#7 ·
Originally posted by bitcore@Aug 30 2004, 06:08 PM
Yep, be sure to get the same size battery or you may run into issues, make sure the terminals are close to where the old ones are and are on the same face of the battery as before (IE: if it's on the top, dont get a battery with terminals on the side)

Your computer may complain once you turn on the car the next time.
You may want to get a yellowtop battery if you want an upgrade or have some powerful amps, otherwise, a standard lead acid will work just fine.


If you are really worried, I'd wait for another person to chime in since I havn't really done this for myself yet, I do have a stock radio and I DONT have the code... so I'm holding off untill I REALLY need a new one.
Come on now fellas,
You guys must know that you can replace your battery without having the codes for your radio... all you need to do is make a trip down to your local radio shack and buy a few cheap parts. A nine volt battery clip, and a cigarette lighter plug, and a few feet of wire. Essentially what you are doing is powering the cars computer and radio with 9 volts for the short period of time it takes to replace the car battery. It is enough voltage to preserve the memory. The only thing you need to remember is not to open the doors or do anything else that will create a draw on that little battery.

Alternatively, you could just use another car battery, hook it up in parallel to your battery leads and then swap your battery out for the new one. with a little care, and maybe an extra set of hands this is an easy thing to do and no radio reset required.
 
#9 ·
Or you guys could have read in the original post it doesn't matter about the code, because he clearly stated he has an aftermarket system w/o a code.
 
#10 ·
Originally posted by El Presidente@Aug 31 2004, 10:51 AM
Or you guys could have read in the original post it doesn't matter about the code, because he clearly stated he has an aftermarket system w/o a code.
True enough El Pres, but look at how many guys are waiting to change their batteries becuase they dont have the code. Despite being a bit of a tangent from the origial request I thought that my post would be useful to those folks who dont have their code and wantg to change their battery. I am actually surprised that you dont have some plans or reference to this battery adapter in your sig, given the high level of electrical knowledge you posess...
 
#12 ·
Wow .... thanks for all the helpful information. I really like this place! I called my local parts place and they have an Interstate battery that is a replacement for this for $100.00 Since it's in the trunk, it needs to be a vented battery (with the little tube that lets the battery off gas to the outside). Are these yellowtop batteries much better? And can you get them on the net for anywhere around $100.00? In a way the battery is kind of expensive since it is only a 530 cold cranking amps battery to begin with. At least that's what it says on my old one, and since it's German, I assume it's from BMW. Thanks again for the good advice!
 
#13 ·
To play it safe, I'd also have your mechanic check your charging system too. Even though the battery is old, its death may have been sped up due to an underperforming charging system (i.e., alternator). In your situation, I think you're safe to replace the battery now and have your mechanic check the charging system sometime in the next couple of months.
 
#14 ·
Originally posted by frank3@Aug 31 2004, 12:49 PM
To play it safe, I'd also have your mechanic check your charging system too. Even though the battery is old, its death may have been sped up due to an underperforming charging system (i.e., alternator). In your situation, I think you're safe to replace the battery now and have your mechanic check the charging system sometime in the next couple of months.
or you could check the output voltage yourself and know before you change your battery... Just ask me if you want to know how to do this... P.S. you need a volt meter preferable a digital one, but they are really cheap, like ten to 20 beans.
 
#15 ·
Originally posted by nycbmw325is+Aug 31 2004, 01:18 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (nycbmw325is @ Aug 31 2004, 01:18 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-frank3@Aug 31 2004, 12:49 PM
To play it safe, I'd also have your mechanic check your charging system too. Even though the battery is old, its death may have been sped up due to an underperforming charging system (i.e., alternator). In your situation, I think you're safe to replace the battery now and have your mechanic check the charging system sometime in the next couple of months.
or you could check the output voltage yourself and know before you change your battery... Just ask me if you want to know how to do this... P.S. you need a volt meter preferable a digital one, but they are really cheap, like ten to 20 beans. [/b][/quote]
hmmmm beans? this sounds like a childrens book...


You will need two wrenches sizes 10 and 13 I do believe. There is a huge bolt runninig down the side of your batter that helps hold it in place. You have to unscrew that bad boy to get the batter out and try not to bend it like I did... then out with the batter and in with the new one hook the top connectors back and screw the bolt down again and you are in buisness... nothing else is nessaccary.
 
#18 ·
Hey guys, I just found an adapter that avoids resetting your radio/computer code
while replacing your battery. It plugs into your lighter using a 9V small battery.
It's only $10 at bavauto... Thought I would share my findings...
Just like what nycbmw mentioned before...

LOS
 
#19 ·
Originally posted by LOS@Sep 2 2004, 02:07 PM
Hey guys, I just found an adapter that avoids resetting your radio/computer code
while replacing your battery. It plugs into your lighter using a 9V small battery.
It's only $10 at bavauto... Thought I would share my findings...
Just like what nycbmw mentioned before...

LOS
yup.. except 10 bucks plus like 5-7 for shippping.. or you could make one yourself for about 5 bucks in 15 minutes.... If i have the time thi sweekend I will list out the parts and directions for making one...
 
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