I own a semi trailer repair shop. We don't work on trucks, but I am around them often. As far as I know, the batteries are NOT deep cycle. I will fully admit though, that I don't know that for 100% certain. I can check Monday and will know for certain.

Truckers leave their trucks idling while using the gadgets, microwaves, TV's, ect in the sleepers on their trucks. That makes me think the batteries are not deep cycle. They leave them running so the alternator will charge the batteries.