Battery connected or not, the Ford tranny is just in neutral and won't go into gear. There is no bearing on the battery versus anything to do with towing. You will need to run a power line for AUX braking, but the reason the battery goes dead is due to the accessory not shutting off because it is in N and not P.
This is a simple tow set up. The Ford needs to be run for 5 min before towing and 5 minutes every 6 hours. You then just put it in N and disconnect the battery. Easy. My SHO follows very nicely and I have had zero issues in 10K towing it.
WW
