might be a defective battery, have you had it load tested? does it have a modern radio with an 'always on' memory? .... put a meter in line on the battery + terminal, when you see current flowing, start disconnecting things until the current stops

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics