Battery recommendations?

[cleanerPA]

My battery ran down while in storage for the winter. What brand and size battery do you recommend for an '01 M Coupe?

I don't think I'm going to use an OEM BMW branded battery. BTW, is there supposed to be a vent line hookup somewhere?
Last time I looked, I don't recall seeing one, although I have an OE battery in there right now.

I'm leaning toward some sort of AGM battery- Diehard Platinum, Optima Red Top, Deka, etc.

[KillerSE7EN]

I believe all bmw z3s use an h6/ 48 size battery, advance auto carries agm h6 batteries, but their gold version has been in my car for 7 years and it's an acid battery. OE crank amps are 650, they will install for free too

http://shop.advanceautoparts.com/web...p2HomeClicked=

[JWin]

This was the one folks were using when I searched a couple years ago: http://www.interstatebatteries.com/c...ery_L6%2f3.2L)

Perfect fit. Lighter than stock. No issues with extended durations of non-usage.

[Wertles]

SAMs club sells Duracell batteries that are rebadged DEKA batteries made by East Penn. I bought them for my truck for about $35 less per battery (the truck requires 2) than the DEKA stickered batteries. I have had nothing but good from them and will be buying them for any other vehicle assuming they are still made by East Penn.

[lokijibber]

This was the one folks were using when I searched a couple years ago: http://www.interstatebatteries.com/c...ery_L6%2f3.2L)

Perfect fit. Lighter than stock. No issues with extended durations of non-usage.

This.

I always use Interstate, but I get a good deal with a 5year free replacement warranty. Just replaced the battery this year as it died over winter. No charge since the last one was installed in 2009. Interstate makes a "vent" kit compatible with this battery, but I was able to use the stock vent from my original BMW battery with no issues what so ever.

[Reddy Kilowatt]

I've always used Interstate.

[KillerSE7EN]

there are only 2 battery makers in the U.S. therefore; in theory, you can go with almost any battery manufacturer and it will work, but you need to make sure it has at least 650 cold cranking amps as this is the factory requirement.

[Reddy Kilowatt]

there are only 2 battery makers in the U.S. therefore; in theory, you can go with almost any battery manufacturer and it will work, but you need to make sure it has at least 650 cold cranking amps as this is the factory requirement.

Well, true. But the specs are relevant, as well as how the local retailer is to deal with, particularly regarding warranty.

[cleanerPA]

there are only 2 battery makers in the U.S. therefore; in theory, you can go with almost any battery manufacturer and it will work, but you need to make sure it has at least 650 cold cranking amps as this is the factory requirement.

Do tell. Johnson Controls and who else?

Even if there are only 2 battery manufacturers, don't the specs differ between brands?

I've used a lot of Interstate batteries over the years, but I don't find them to be anything particularly special. I know a lot of people have issues
with Optima batteries, but I have not- I've used two different Red Tops in two different cars, spanning nearly 10 years, no issues, car starts up
right away. But the big thing is, these cars sit most of the time and they sit on a battery tender.

With recommendations for Interstate, Deka, Advance Auto, I guess I have to do more homework. Is there any reason (besides cost) not to go with
an AGM battery? I like the fact that an AGM battery does not have "loose" liquid H2SO4 that can leak out and corrode stuff, especially for a battery
that is in the "interior" rather than under the hood.

[Reddy Kilowatt]

Coincidentally, my battery was dead this morning. It got an Interstate battery. ~$150 + tax.

- - - Updated - - -

My battery ran down while in storage for the winter. What brand and size battery do you recommend for an '01 M Coupe?

I don't think I'm going to use an OEM BMW branded battery. BTW, is there supposed to be a vent line hookup somewhere?
Last time I looked, I don't recall seeing one, although I have an OE battery in there right now.

I'm leaning toward some sort of AGM battery- Diehard Platinum, Optima Red Top, Deka, etc.

To answer the question about the venting, mine had about 6" of vent hose attached on the front of the battery.

[Jamesons Viggen]

I am heading over to Advance today too, mine is a dud as well after winter and under warranty.

Don't forget this nifty coupon.
http://www.techbargains.com/news_displayItem.cfm/343156

[KillerSE7EN]

I am heading over to Advance today too, mine is a dud as well after winter and under warranty.

Don't forget this nifty coupon.
http://www.techbargains.com/news_displayItem.cfm/343156

be careful that coupon is for online orders only, although you may be able to use their $10 off coupon that randomly floats around.

I'm gonna do some preventative maintenance and buy a new advance battery to replace my 7 year one ahha

[Jamesons Viggen]

be careful that coupon is for online orders only, although you may be able to use their $10 off coupon that randomly floats around.

I'm gonna do some preventative maintenance and buy a new advance battery to replace my 7 year one ahha

Yeah, its online but with atore pickup. What's wrong with that?

They replaced mine under warranty, no questions asked, didn't even ask for the receipt.

[KillerSE7EN]

Nothing wrong at all lol I was trying to save you heartbreak if you were gonna try to use it in the store lol
they are awesome, love the awesome online deals.

[rdsledge]

Walmart three year replacement $105.xx

[cleanerPA]

I was bummed- Advance Auto did not have the AGM version in stock anywhere in the entire Philadelphia area. Thanks to Jamesons Viggen, I saved $50! Thanks man. $109.17 and I'll get $15 back when I give them my old battery.

BMW branded replacement battery from September 2007.

[Jamesons Viggen]

I was bummed- Advance Auto did not have the AGM version in stock anywhere in the entire Philadelphia area. Thanks to Jamesons Viggen, I saved $50! Thanks man. $109.17 and I'll get $15 back when I give them my old battery.

BMW branded replacement battery from September 2007.

Nice!

They didn't even ask for any paperwork from me, so if anything happens 3 years from this one, I doubt I will have a problem getting another free replacement.

Fired right up with the new battery. Made me forget instantly about the other BMW or any other car for that matter lol.

[Kenn]

I recently bought an Autozone Duralast Platinum H6 AGM battery. It fit just fine, and the vent is in the right place (unlike my previous Interstate MTP-91, although it was just a matter of putting an extension hose onto the stock hose). Regarding the AGM battery technology, it seems like the life of these is questionable. From searching online, there are some research-type papers (which I couldn't quickly find again) that suggest they may not last as long as conventional batteries. The Autozone warranty on their "platinium" AGM battery seems to back this up. Three years full replacement, and no warranty beyond that. I guess I'll know in several years how well they last, at least for my usage ( previous Interstate lasted 7.5 years).

Quotes from a search on AGM battery lifespan:
In most cases AGM batteries will give a longer life span than a wet cell battery, but will not stand up as well to hot temperatures and high discharge load.

http://batteryuniversity.com/learn/a..._glass_mat_agm

Says useful life is shorter: http://en.wikipedia.org/wiki/VRLA_battery

[cleanerPA]

I like the fact that AGM batteries are not "flooded" like your typical lead-acid battery- it is much less likely to leak because of this and can be placed in pretty much any orientation. I've had good luck with AGM batteries- I've had an Optima Red Top in both my STi and my C6, had an Autozone AGM battery in my Miata. Started up every time, never had any issues. The STi's battery lasted 4 years (then I sold the car, so no idea on longevity) and the C6's battery has been going strong for 5 years now. I keep them on a battery tender, so that probably helps- of course you must make sure that your battery charger and/or tender is AGM compatible. Both my charger and tender are AGM compatible.