Battery Bosch or Deka

I have some extended experience with a lightweight battery in my daily driven 2006 Boxster S, which is well known for the demands it places on the battery. In spite of that, I successfully used the Deka ETX30L (21 lbs.) for almost 3.5 years.

Alright so i picked up a bosch 750 cca battery and threw that in her on another -10 F day, cycled the glow plugs once and she fired up like it was a mid summer day. Hasnt given me any trouble since and its been nothing but cold here.

I'm using a Bosch Group 48 battery (it is 26 months old now) from Pep-boys. Their testing machine result says 'good battery' The guy at the store said, it was as good as a new one.

new bosch battery

EDIT: Confirmed fitment (duh) and ordered the Deka through Batteries Plus. This battery seems to be best fit as its reserve capacity is nearly double that of the Optimas.

I have had excellent results from a Deka Intimidator 9A48 High Performance AGM Battery Deka / Remy part # 9AGM48 installed Dec 2010

I don't recommend anything less than the DEKA ETX-20L for a car that see true street duties. The ETX-14 is 200 CCA @ 12 lbs, and the 4 lbs weight loss isn't worth it for 70 CCA loss on a small battery in charge of starting a car. The ETX-18L does 270 CCA @ 16 lbs and much more suitable for our 4 banger application. The ETX-18 however is the one I recommend to 95% of readers of this thread. It cranks out 300 CCA at 18 lbs, which is still plenty light.

I've always had sucess with the Deka ETX-20L in the DSMs, two EVOs, a Saturn race car, and now the TT (most of them running on E85 which is hard to start on cold winter mornings). As long as you discipline yourself to not run accessories with the engine off, they are a great option!

At one time Bosch batteries had a terrible reputation but they now have their quality control back on track.

I just upgraded mine a few weeks ago, ended up getting a DEKA AGM 9AGM47 More CCA and far more reserve capacity than the stock battery (120 mins) I was at ~35k miles and my OEM battery was failing fast.. I couldn't leave it in the accessory position without the engine running for more than a minute or two or it would barely be able to crank. The OEM battery is crap as far as I'm concerned