I just bought a Braille 11.5 pound Daily Driver Battery, mostly because I was going to have to replace the battery in my Audi A6 and decided I'd rather buy a "Fun" battery for the Mini rather than a boring battery for the car I'm giving to my sis.

(if you didn't catch that My mini gets a new bat, the A6 gets my mini's bat, and mini drops 30 pounds)

So the question is How many bolts/nuts/screws have to come out to remove the huge black sheild over the battery compartment? and are there any "gotcha's" I should be aware of.

Oh I didn't splurge on the $50 bracket for the battery cause I didn't see it until this morning, so I'll likely be bending my own.

(I liked when the battery was in the boot instead of the bonnet, for making this swap)

Brandon
-Greatest Living American

PS
If you leave a good tip I'll mention you in the YouTube video when I do the Swap.

 

It's been a couple months since I pulled the cover off the battery, but it wasn't too bad. As a side note, I'll probably get a Odyssey PC 680 when it's time to replace the battery. I had good luck with it in the Subaru.

-JL

 

I can't help you with the battery install, but the Braille sounded interesting so I looked it up. The one on TireRack.com is 15 amp-hours. RealOEM.com lists a 50 AH and a 70 AH battery for the MCS. Is 15 really going to be adequate?

 

I live in California so I rarely have a cold day, and certainly none of the kind of cold days that drain a battery. Typically you can start even a big engine in under 5 amp hours.

Think of it like this... How many seconds does the engine crank for? In my mini it is less than 10 ( think it is about 5 ) so if you had 600 amps for 10 seconds you would have used 1.6 amp hours.

15 amp hours would get you 10 starts.... The problem is that you have to recharge at some point, and since you typically recharge at a rate of 15 amps it would take you 6 minutes to recharge. So if you made a 6 block run to the 7/11, and then a 6 block run to the block buster, and then a 3 block run to the gas station, you could have started your car 4 times and not done enough recharging so the next time you started your car you'd be on your 5th start, and have used 8 amp hours of juice... (which is why I didn't get the 6 pound battery)

The other problem you can have is that just sitting there your car will drain about .5 amp hours a day. so in a month of sitting the car might need a jump.

The 30 pounds of weight can be quite a performance boost, Especially if you are trying to catch up with a 100 pound girl. I can never weigh as little as some of the 5 foot 4 girls that drive fast compacts, so I'll take my weight loss where I can find it. 30 pounds on the battery, 11 pounds on the exhaust, 50 pounds in the rims and a 6'4" guy can almost even the playing field.

 

They don't really work like a checking account, Drakaal. Sorta....but not that precise.

 

my limited understanding on batteries is that you have to look at the CCA rating or Cold Cranking Amps. Since batreries loose their power as the temp goes down the bat. is rated at like 0* C or something like that I don't remember exactly.

Sorry cant help you specifically with the original question. If it was me I would just start wrenchin and explore which bolts you've gotta remove as you go, thats the fun part

 

Batteries have several measurements, but yes Cold Cranking amps is an important one if you live in a climate that has days that are below freezing.

Batteries have a "max load" or max draw rating which is bassicaly "Warm Cranking amps" this is measured in Amps.

Capacity which is measured in Amp hours. Basically how many hours at a 1 amp draw.

Cold Cranking Amps which is the maximum discharge that can be sustained for 30 seconds at 32f/0C

Lead acid batteries have a lower voltage the lower the amp hours remaining, so often you cant use all of the power in them. (typically you can get about 60% of the amp hours at 85% peak voltage)

Dry Cells have much less voltage fall off, so you get 85% of capacity at 85% peak voltage. This means a dry cell can be more "dead" and still work, but you get less warning as it dies. You can tell when your lead acid is low cause the car starts harder. with a dry cell you come out one time and just hear click, click, click.

I'll let y'all know when I make the swap and post the how to video.

 

Getting the lower windshield cover off is simple. It is in two pieces--left and right. You need the left hand one, over the battery. Pull the rubber hood gasket off the the lower part of the cover , it just slips off. remove the two black plastic nuts at the left side of the cover. Gently but firmly slide the cover towards you while pressing down on it to unlatch it from the gasket strip that runs the length of the window glass. You will then have a full view of the battery.... DJAM

 

djam43 helped me out when i was asking the same question in the audio forum (thanks again!)
BUT
it was not easy at all for me. it was actually quite difficult. once i put a little more force on it, i got it to move. i was stuck for quite a long time on the fact that the right and left trim pieces were stuck together. When i got the left side loose, apparantly i had removed the piece that holds on the trim that we are talking about.
Overall, i'd say it sucked and i am sure that it will suck again even though i have done it.

After that background, my advice is to follow djam43's advice. IF the pieces are stuck together, get a good light and look at the bottom edge of the glass and you will find that it is bare. investigate the side edge of the trim piece and you should see the "clip" edge. I was able to use a flat screwdriver to start the disconnect operation and then continued along until the left side came off.

 

Djam43 and KookMyers thanks for the tips, that is exactly the information I was looking for. I'll drop your names in the How To.

 

Is the benefit of the battery just to shave weight??? If one was to be autocrossing, would that not take them out of G stock?

 

Install went smooth. Will edit the video over the weekend and get it posted. Thanks for all your help. And the discussion of how batteries work will get me a great start on some text to go with it.

This will help me sort out what I want to do with my how to install a complete alta exhaust system.

PistWalrus....
While I was mostly looking at Weight, I was really looking at fuel economy. I have been looking at performance upgrades that don't hurt my MPG.

Shaving 30 pounds saves 9.7 calories per foot. that is 51 Kilo Calories per mile. A gallon of gasoline contains 31,000 kilo Calories so if my Mini were 100% efficient (its not) in a 20,000 mile driving year I would save 32.9 gallons of gas. There is no specific number for the efficiency of say the mini engine, but since the EPA claims autos are between 22 and 48% efficient (based on the number of calories used to move a vehicle verse the caloric content of fuel used) if we assume a mini is 50% efficient then I will save 65 gallons over the year and at $3.20 a gallon... that is $208 which means the upgrade saved me $55 the first year.

Feel free to use this rationale when you pitch your wife on those racing rims you have been wanting.

 

I had no idea the OEM battery is so heavy - wow.