I would be more concerned about the safety of the 110v side of things.
The switch you use has to switch both sides of the 110v system. The van
is small enough that things can just be plugged into the inverter and
just let the fridge run on 12 volts while driving. As for the
thermostat, the fridge will never freeze your soda or milk anyway and
except in the winter, it will always turned all the way up so that is
not a benefit. Most inverters will try to run with the battery down to
10.5 volts and at that pint it will take 4 hours or more to fully
restore it so some battery damage will occur anyway.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Edward Maglott
Sent: Tuesday, April 18, 2006 9:34 PM
To: vanagon@GERRY.VANAGON.COM
Subject: battery-inverter-charger-battery loop

I'm working on a setup that would use one switch to switch all my AC
outlets from Shore power to inverter power, and power on the inverter.
I
see the potential for this error to occur: I'm plugged in to shore power
and running my battery charger into my aux battery.  I flip the switch
to
the inverter power and forget to turn off the charger.  So now I've got
a
loop with the inverter drawing power from the battery, changing it to
120v
AC, the charger is taking that and turning it back into 12v DC and
putting
it into the same battery.  I know this is stupid and a waste of power,
but
is it dangerous?  It seems like I've read warnings about this type of
situation or something similar creating some sort of feedback loop or
something.  The other option is to leave one outlet only and always
connected to the shore power, but that is more complicated...

Edward