If cost is a factor just get Walmart's $40 standard group 41 battery and
put it in the other battery compartment under the driver's seat. You can
buy a battery switch or a heavy duty relay for about $20. Add another
$20 for wire and connectors and you can do the whole thing for under
$100. If you like, put the new battery in the main battery position and
use your old one for the aux battery. I use this approach and cycle in a
new main battery every 2 years and move the old one to the aux position.
This way I always have a fairly new main battery for starting.

Mark

Terry Kay wrote:
>
> Scott,
>
> The idea of having an extra battey is to lessen the chance of you
> running the primary starting battery down while camping.
>
> I myself, would enjoy the thought of knowing that I have an extra
> battery besides the one I'm using for the house current.
>
> Johnson Controls makes one hell of a battery--Optima is the best your
> money can buy.
>
> If for some reason the monetary outlay is a little much for the
> Optima--hit Walmart--they have deep cycle batteries cheap.
>
>  Two is always better----Right Benny?:>)
>
>             ______________
>            |[  ] [  ] [ ]\
>            |    |    |    |
>      ~~~ ~||-(())----(())-|
>
> Terry--
>
>        "Zoom, Zoom, Zoom"
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~