tipper

The knife switch would work -- We use these in our automotive vehicle displays, having the knife element extend through a slot cut in the top of the battery box, both to indicate it's state and to provide a mechanical lock out.

However on my TM...

I use a double banana jack through the battery box's side [fuse inside the box].  The TM power wire therefore has a double banana plug for its wire.  This allows an easy disconnect for the battery.  The red and black color polarity markings must be always carefully observed!

I have an external battery charger also with a banana plug to recharge the battery and/or to help power the TM's refer and fan while not under A/C such as preparing to depart.  

I also made a 6' long 12awg wire harness having a trailer side 7-pin pollack connector to a double banana plug, so that I could simply lift the battery by its box from my TM's frame and charge it in the back of my van during an errand/day trip if required while dry camping.  [There is a 30 amp fuse in this harness]