Best Battery for B7 A4?

[patricketc]

Hello all,

Hoping to get some help from the experts here.

I own a 2006 Audi A4 2.0T quattro. It's been an absolutely fantastic car and has been a great daily driver the past 9 years.

I recently bought a new car, and unfortunately left my Audi sitting for about 2 weeks in my garage and the battery died.

What's the best battery choice for these cars? I was running an Optima Red Top 34R, and that worked flawlessly for about 6 years, but I'm not sure if that's the right size for the car or if there's a better choice out there? I intend to drive the car about once a week, although there may be periods where it sits for longer. I would prefer an AGM battery.

I haven't been able to find much information on the size or specs of the battery needed for this car. Some places say H7 / group 48, others H8 / group 49 / 94R?

Any help you guys can provide would be much appreciated.

Thanks,
Patrick

[Jayz691]

The factory size is H7, but I use an H8, just gotta remove the little bumper piece, on the battery tray. The H8 AGM was about $100 cheaper than the same battery in an H7. But not sure if something else, like a deep cycle, would hold charge better between starts.

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[oVeRdOsE]

depends what you're doing with your car ; fully loaded and you use all 4 heating seats + aftermarket big subwoofer? then you can stick with higher cap battery like the 94r (h7).

I went with a smaller group 35 AGM battery. Yes it bolts on safely . iirc it has 13 or 17 pounds less than my OEM battery.
yeah drop from 900A crank to 755A, but still work fine after 2 years.

[430hps4]

H7 AGM @ Costco = Interstate battery with 36 month warranty

[007J]

I've been wanting to swap to an Optima Red Top for weight savings, think I first heard of that from Nick's Car Blog.

[patricketc]

Quick update: Thanks to the advice here I went out and got a Duracell Platinum AGM 94R from Batteries Plus. The 94R is basically an H7 size in the US. This battery should be a good choice since it's made in the US and is apparently built to tolerate not being driven much and having a wide temperature operating range.

94R batteries fit well in the battery area, since they're basically the stock battery size. Did a bit of cleaning in the battery area and cleaned some light corrosion off the cable ends. With a 94R battery installed the plastic stopper in the battery tray will fit into the last available slot. Somewhat of a tight fit trying to get it down into the slot with the battery installed, so consider doing this before you drop the battery in there. Previously when I had been running a 34R Optima Red Top, the stopper was in the 3rd slot from the right, but the battery would still slide around a bit if I pushed it. Thought that might be helpful info for those considering alternative sizes.

Appreciate everybody's help, car is running great now.