Select your next battery with care.  Note that the Interstate
MTP-91 is 6.88" high.  The group 41 is 6.63".  A while back
folks got excited over the Odyssey 1200, which is 6.80"
high--then found the battery cover wouldn't go back on.  We
know the group 41 at 6.63" fits; higher does not.

Bigger is better with batteries--at least in amp-hours and
aux batteries, but figure what you need.  I have an Odyssey
925 which is smaller, both in amp-hours and height.  It
fits easily into the battery compartment--with the lid.  It
runs my lights, CD stereo, and Carver furnace; I wouldn't
ask it to run my fridge. It has about 27 amp-hours in it vs
41+ for the 1200.  Here are my electric comsumption figures,
from manuals:

        watts                           amps

        85      fridge heater (12V)     (7)
        0.6     fridge fan              (0.05)

        0.36    LED lights              (0.03)
        8       ThinLight               (0.67)

        (26)    stereo (max)            2.2
        (30)    Carver (max-high)       2.5
        (14.4)  Carver (max-low)        1.2

I use the stereo at night and the Carver in the morning.  ;-)
I could probably go 3 days on my 27 amp-hours without recharging
before it was quiet and I got cold....

Richard
Boulder