Dan,

Thanks to so many of us showing up crewless and to CDs who call tasks with the intent of getting most or all pilots home, it's relatively rare these days that I have to hook up the trailer to my van very often during a contest: once in the past five nationals, IIRC (not counting several aero retrieves at Elmira).

And at sites with favorable weather and my new polyurethane finish, I'm tying out at night much of the time at national contest sites unless storms threaten. As I said, removing the tail battery is no big deal, although if I'm tied out, then I have to remove the elevator to get access. I'm just lazy. It's easier not to put that battery on the line unless I have to--then it's good for the whole contest.

Hence, my two switch (or my DPDT switch before it got shot up at TSA) approach makes the most sense for me. For those using batteries with wildly different capacities (e.g., motorgliders) or avionics drawing a lot more amps than mine do, a different approach might be in order.

Chip Bearden
JB