> The best way to keep an aux. battery charged is by
> using a battery isolator.

Well....

'best' is often dependent on your point of view....
we've hashed this over may times with some pretty smart people giving the
input and there has been no consensus yet as to the 'best' set up....

for instance,
some think a manual switch is best... it gives them ultimate control...
some think using the existing 'fridge relay' is best because it is easiest,
cheapest, automatic, and doesn't have the voltage loss (better battery
charge) that the isolator has...
some think the isolator is best because it keeps the two batteries
separate...
some think the new electronic 'battery separators are better than the
isolators...
I forget all the fine points... but it seems to me that if someone really
wants to find the 'best' aux battery connection for their particular use it
would be worth the effort to read the archives for the past year....

Bill