My battery just died and wanted to replace it. Is there anything different about BMW batteries? I am thinking of getting an Optima Red Top. They have 720 and 800 CCA (Cold Cranking Amps). I was told that 720 should work out better since this is a 4 cyclinder motor and the person said that the energy from the smaller battery is higher.

Thanks
Carl

 

There is nothing exceptional about the provided BMW battery, except for the fitting of an external gas vent tube needed with the MCS battery mounted in the passenger space. An Optima or similar AGM or gell-cell sealed battery of similar capacity and size would suffice, but any sort of 'wet' cell should be fitted with the vent tube not only for the venting of dangerous hydrogen gas, but also to prevent any sort of electrolyte seepage into the battery box, which would corrode it rapidly and cause damage to the body. There is no replaceable battery tray as most cars have, and the thin sheet metal of the trunk floor/battery box is all welded in place and very time-consuming (and expensive) to repair.

 

I too am looking at the Optima...do you have a part number for these Carl?

Thanks,
Sid

 

SID,
I have been checking around and I found out that we the OEM bat is a Group#47, which means that the terminals are reversed. Most off the shelf Optimas are the other way around. I went to the Optima Website and I am going to look if they offer one. The guy at Batteries Plus told me that the 720 CCA will do fine as the oem batt is rated at 480 CCA. He even said that the smaller bat would in theory have "better" energy since the recharge cycle is less. I still am learning about how batteries work so this is just what I am recanting.

I will update soon.
Carl

 

Thanks Carl

 

I just found out that Odyssey/Braille has one that is rated for 1200 HCA (Hot Cranking Amps) and around 700 CCA. This will fit the MCS. 7.8 W X 6.5 D X 6.6 H. His price was $169.99 from Batteries Plus.

We can also use the Group 25 Optima 720 CCA with the standard post orientation. Just turn the batt around.

I found the Red Top Optima (group 25) at Autozone for $109.99 with exchange.

I am most like going with this one.

Carl

 

By turning it around (group 25), do you mean just reverse the polarity? When I go to AutoZone, do I just ask for group 25?

Also, do you know if these are deep cycle capable? I have a tendency to occasionally drain my battery while working on my Mini...of course, that's why I'm shopping for a new battery

Thanks again,
Sid

 

The MCS battery has the terminals 'reversed' from normal. Looking at the battery from the top, with the edge closest to the terminals facing away from you, a 'normal' battery has it's positive terminal on your right. The MINI battery has it on the left. The battery itself is installed with the terminals facing the rear of the car, with the positive on the right. Many Optima batteries have the terminals centered on the battery top, making them able to fit most orientations.

You can turn a 'standard' battery around so it's terminals are on the proper side, but your typical offset terminal battery will put the positive terminal near the front of the battery box. This is not a problem for the negative terminal, but the positive terminal with it's two cables and 'safety terminal' charge assembly would be cramped in that position unless you have space enough to rotate the terminal 90 degrees or so for clearance.

Make sure that any battery you get is not much taller than the original when measured at the terminals. You dont want the weight of objects in the trunk bearing down on the terminals if the new battery holds the floor mat up higher than normal.

 

I'm going to have reread this a couple of times...even for a designer, I'm having a hard time picturing thislol: Perhaps it would help if I take a look at my battery...haven't done that in a long time...

 

SID,
The red top is the non-deep cycle. The Yellow Top is the one you need. The price jumps to around $169 though. My friend at work swears by the Yellow top, but I will try the red. There is a 3 yr replacement warranty on the reds.

Great Bear,
Do you have a picture of the components on the + side that I should be concerned about?

I am thinking that I now can use the quick disconnect on the neg end because the optima terminals are not in a pocket like the OEM's.

CARL

 

SID,
What type of designer? Industrial? I am an Industrial Designer.
CARL

 

SID,
I forgot about the group 25 optimas. You will see a 75/35 on the label on the shelf for the off the shelf batts. THe part # is SC75U. The "U" stands for auto tops and auto side connections.
CARL

 

Howdee Brother I started in Industrial Design at school and moved to Transportation...been at Ford and GM for over 20 years now

 

Since our wonderful forum software strips extra spaces from posts, I cant really show via text like I want to. Imagine these diagrams widened to about an inch.
___
|o o|
|- +|
|___|
"normal"
___
|o o|
|+ -|
|___|
"MINI"

___
|- +|
|o o|
|___|
"Optima" (in some applications)

 

Thanks Greatbear...pictures I can understand

 

SID,
I went to OSU for ID. I started designing boats, then refrigerators and now carpet extractors. Are you working at ford or gm?
I get the battery in and see what needs to be moved or modified and I'll post pics.

GReatB,
Thanks for the help.
CARL

 

Please do post pics after your install and perhaps I'll follow suit...

I was at Ford for 16 years and have been at GM Design the last 6 years I graduated from Center for Creative Studies 85' in Detroit...

What's a carpet extractor I though illegal aliens did that job

 

My stock battery ain't dead yet, so I will eventually need to 'Optimize' my car too. The stock battery sure doesnt like being drained for long during projects and 'experimenting'.

 

SID,
LOL. I design spacecraft that suck up Dust Mites.... I work for BISSELL. Do you know of an engineer at GM named Jim Armas?

I am buying the optima red tomorrow and my son, Ryan(10 months old) and I are going to install the battery.

CARL

 

I want to see pictures of your 10 month baby mechanic

I get that kind of questions all the time but you know the answer..."uh...GM has a LOT of people working in one square mile" Sorry...I haven't met Jim yet...

 

Here is the little hoodlum.

 

Very sweeeet A goil?

As this your thread, I'll follow you OT...My 2 year old "Mini Mechanic"...



Am I correct in assuming there's a little almond eye going on here?

 

I've often wondered what are the advantages of a regular v a deep cycle battery. A deep cycle battery makes so much more sense as it can be used for whatever when you're not going anywhere. But does it fail if it isn't discharged regularly? Who knows?

 

Beautiful Boy!

You are correct in your assumption. My son is half filipino, 1/8th dutch, 1/8th german, 1/8th american indian, 1/8th I have no idea. He is a direct decendant of General Lee, the historic general of the Civil War though. A pure mut and I can say definitely a rebel.

 

Bluebonnet,
The optima site says it is a deep cycle. The same that bass fisherman use on their boats. So discharge cycles are fine and will not shorten the life of the battery I assume. But check the optima website.