The 6v batteries are more forgiving about being run down to "dead" but if it happens enough, the batteries will sulfate and, eventually, be useless. The parasitic loads, as mentioned, will have your batteries discharged in a matter of days.
One of the better ways to maintain the TT's batteries when in storage, is to use a small
solar module to keep them charged. Pair the module with a
battery disconnect switch and when you pick up the TT from storage, turn the switch and you'll be off with charged batteries.
