Question on battery size/dimensions?

[Wayne's World]

OK guys - been reading numerous threads about what battery is recommended, most used, etc. After two or three times now of having the battery die at random times and it's going on 5 years old, I figured it might be time.

So far what I've come down to, is it needs to at least meet the amp/hour (AH) and reserve capacity (RC) requirements of the OE battery.

I have a 2006 3.0 E53 and after much reading, I decided to actually have a look at the sucker. The battery indicator is not green, instead dark which translates to "insufficient charge" according to the label. Also according to the label, 640 amps, 640 CCA, 80AH, 140RC. Size is (from my measurement with a tape measure while still installed): 12.25W x 6.75D x 6.75H.

My problem is, every online catalogs I've searched, tells me I need a group 49. I saw a writeup and it looks like I need a 94R. I've also seen a post on this board stating it's a 94R. What confuses me is all the online catalogs seem pretty definitive that up until 2005, it's a 94R for the 3.0 engine. Then in 2006, all the catalogs somehow switch to group 49, even for the 3.0 engine.

?

[mywidebody02]

those batteries cant be much cheaper than oem.

[Wayne's World]

Originally Posted by mywidebody02

those batteries cant be much cheaper than oem.

Which batteries?