james ,

a tip to find whats dropping the battery.
disconnect the main live from the battery and if you have several light feeds as well as a main feed to starter re connect them all in turn.have the ign fully off and watch for small arcing/sparks when you connect the leads.you might be lucky enough to find just one.
next
disconnect all the lives again and just reconnect the sparking one,then go to car and put ign to "dash lights on".dont start!!!.
just find the accessories that work and you current draw is one of those....ie alarm/clock/stereo

micky ,

have you a battery isolater on that track day yoke

rob