found a good source for AGM batteries

[dkindig]

This info is buried down in a battery thread on this site so I thought I would generate a new thread to get all the info in one spot. I have wanted to go with an AGM (Absorption Glass Mat) battery. If you search for the Deka 9AGM48 battery the best price you will find is at Remy Battery for 174.30 shipped (to Georgia).

In the other thread a gentleman had mentioned Tri-State Battery. They don't turn up in search results because the Deka 9AGM48 isn't listed on their website. I called them and they DO stock this battery. Price is 149.95 with free shipping on any order over $50.

Tri-State Battery
(800) 852-9700
www.tristatebattery.com

[fmcfad01]

never heard of any of this. Educate us.

[JoshS]

This is what I use in the race car.

This is a standard Group 48 replacement battery, same size, clamp-down style, posts, etc, as the stock battery in our cars, so it's a simple, drop-in replacement, no funny business.

Except that it's an AGM battery, not a lead-acid wet-cell. AGM is the same technology used in the Odyssey batteries, among other fancy brands.

I get mine (I've had two) from a local distributor here in San Jose, no shipping necessary in my case. I *think*, but I'm not sure, that it was $130 or $140. You can find the names of retailers on Deka's website.

http://www.eastpenn-deka.com/assets/base/0379.pdf

BTW, since someone will ask -- since these are full-size AGM batteries, they are not weight-saving. They weigh about the same as a lead-acid unit of the same size.

[Cup of Coupe]

For environment or performance?

[JoshS]

For environment or performance?

In my case, neither, it's because of the idiosyncracies of the racing rules for the class I race in.

Details (skip ahead if you don't care!) They say (paraphrasing) that the battery needs to be in the stock location, and that it needs to be the stock size. They also say that if it's inside the passenger compartment, a wet-cell battery has to be inside a marine-type battery box.

Well, for Z3 Coupes, our batteries are inside the passenger compartment (remove the trunk floor and there's literally nothing between you and the battery), so a wet-cell would have to be stock-sized, in the stock location, AND inside a battery box. I couldn't find a battery box that could accommodate a stock-sized battery and fit in the stock location, so I had to find a non-wet-cell stock-sized battery.

But generally, AGM batteries are considered to be better about being deep-cycled than a standard wet-cell, and are less dangerous if the case cracks open. Probably other things too.

I don't bother with these in the daily drivers, but they are nice for the race car which sometimes just sits for weeks at a time in the trailer.

[Ron Stygar]

For environment or performance?

Both:
http://www.bimmerfest.com/forums/sho...28&postcount=6

Z4 M's come with it.

[Cup of Coupe]

I don't bother with these in the daily drivers, but they are nice for the race car which sometimes just sits for weeks at a time in the trailer.

Do you think the extra life could make it worth it? Living in MN the coupe sits, believe me (though I haven't had an issue yet). And I'm down for the longer life.

I might look into this when its time. Thanks for the link!

[TerraPhantm]

Both:
http://www.bimmerfest.com/forums/sho...28&postcount=6

Z4 M's come with it.

Reviving an old post, but I think it's decent info. I looked up the part for the 325i SULEV, and the battery is manufactured by East Penn - same guys who manufacture the deka batteries. You may as well save a ton of money over BMW and buy the Deka brand batteries (9AGM49 for 95Ah, and 9AGM48 for 70Ah).