Derek, a couple questions and thoughts:

This battery is listed as 13" long. Vanagon battery boxes are 12" long. If
it fits with no use of a sledge hammer on the sheetmetal, then Sears has
miss-stated the size number - it would be a group 27. 'Fits' would mean in
would be totally enclosed in the factory box and not protrude. It appears
that it would protrude 2.5", as it is listed at 9.5" tall.

I have a pair of Lifeline group 27 deep cycle batteries ready to install in
my 'big trip' rig - one of the industry's leading brands, cost was $270 each
(local distributor) and are 100 a/h. These measure in at 9.25", but can get
away with 9" if you remove the bolts in the posts - has posts with threaded
centers. I will be modifying the boxes to keep them totally covered and away
from the seat swivels. My second choice would be Trojan.

Karl

 On Tue, 1 May 2012 12:53:11 -0400, Derek Drew <derekdrew@DEREKMAIL.COM> wrote:

>I chimed into the thread at
>http://www.thesamba.com/vw/forum/viewtopic.php?p=6013002#6013002 the
>following information.
>
>I am probably among the first to have fit such massively long-lasting
>and powerful batteries into the front two underseat locations so I am
>passing it along that it can be done:
>
>Derek wrote, in the thread:
>
>I installed under the drivers seat the Sears Platinum deep cycle
>PC31, group size 31, similar in size to Odyssey PC 2150. This battery
>has 205 Reserve Capacity, unlike the group size 65 / PC1750
>batteries, which have more like 135 reserve capacity. The group size
>31 also beats the group size 65 with 100amp hours vs. 68 amp hours
>for the Group 65. The front seat still swivels. The battery sticks up
>higher than it normally would, but is hidden behind the grey rug. In
>order to do this installation, you have to trim the corner of the
>seat swivel (which doesn't look bad) and also trim some metal from
>the area under the driver's seat. Would I do it again? Yes.
>
>The battery under the drivers seat is Sears Item# 02850131000 Model# PM-1.