Unless Phoenix changed things as of late, the knurled rod handle latches for the Sanicon system and the battery compartment are unique to everything else. To operate them is a bit tricky until you understand how they work.
You have to align the pivoting latch-lever to the slot in the body of the motor home by unscrewing it more (rarely tightening it more) so it swings into the slot as you tighten it. Once you think you got it into the slot, gently pull on the knurled rod to confirm it is hooked into the hole, then tighten further. When you get better at it, you can feel the 1/4 turn swing and be even more confident with the latching. Once you get the hang of it, you will never have trouble again.
I feel it is a very nice latching system for the application. I advise to spray some silicone lube on the back side annually to keep them easy-turning. Silicone lube will not attract dirt like other lube sprays.....and a lot of road dirt swirls around in those areas being exposed to the elements as they are.