How to change out the Touareg V10 TDI rear battery (Starter battery)
Tools needed: 10 mm metric socket and driver, battery. Total time for changing battery is about 10 minutes.
The V10 has two batteries, one lead-acid type forward under the drivers seat (Accessories battery) and one (Absorbed Glass Mat AGM type) aft under the spare tire (Starter battery). We'll be tackling the rear starter battery.
We got a variety of stories from aftermarket battery dealers (Interstate, Optima, etc.) but no one knew what battery the V10 took without looking at it. It was also not clear if the front and rear ones were the same. We opted to replace the battery with a factory issued Varta battery. The VW part number of the original battery was 3D0 915 105 G. It was an 85aH, 480 Amp battery. The dimensions are 7" wide x 7.5" tall x 13 3/4" long.
Getting Started
The old battery came out by unplugging the vent tube on the right side, and using a 10mm wrench for loosening the battery lug clamps. On the right side at the bottom is the battery hold down, which also uses a 10mm nut.
Loosen the two for the battery posts and remove the one for the hold down. The battery will slide slightly to the right and then can be lifted up and out. Installation is the reverse.