should the system always have a current (ie hook up a backup battery while changing out main battery)?

I'd love to lose some weight and go li-po or other more modern battery tech but it's so expensive and the weight bias is naturally in the rear, going lighter in the front / center front only exacerbates this.

prob will go with Interstate...

Thoughts?

 

never mind...search is our friend.

:-)

 

PepBoys in my area had the Bosch (OEM Porsche size; i.e., huge) it has more CCA's than the Walmart EverStart Maxx I went with. I keep a Porsche battery maintainer on the battery if the car is going to sit idle for a couple of days or longer. IIRC, the size 94 is the Porsche size.

Both had vent holes and plugs in order to route your current vent tube.

 

https://rennlist.com/forums/996-foru...t-battery.html

I prefer AGM (Absorbed Glass Mat) Gel type batteries
I replaced an Interstate MTP-H7 With a Braille 7548 AGM battery - direct replacement.

Braille AGM B7548 battery group 48
BCI Group: [?]Group 48
Length:10.9" (277mm)
Width:6.8" (173mm)
Height (without posts):7.5" (191mm)

http://www.braillebattery.com/index....durance_series

Braille has tripled $$$ since I bought mine. Look at the Sears AGM mentioned below.

Battery sizes that fit 996 (group 49 will probably need a nut under the last, unthreaded, hole in the tray)

Group Interstate number Dimensions L x W x H Posts
48 MTP-H6 10-15/16 x 6-7/8 x 7-1/5 Top
94R MTP-H7 12-3/8 x 6-7/8 x 7-1/5 Top
49 MTP-H8 13-15/16 x 6-7/8 x 7-1/5 Top


Also
Diehard AGMG GP48 Item #22850748 for $174.99. as of 7-31-13