How old are the batteries?
I have a Workorse Motor home I think the battery is a Group 78 (Side terminal) The Side Terminal (Common on GM products) is not supposed to need terminal cleaning they tell me... DO NOT BELIEVE IT
I'm now on my 3rd battery
#1 they used the wrong lug on the wires on the positive terminal so I had to clean it every few years.. Finally cleaning did not hewp (9 years old) So I got a new battery. and re-did the lug to a proper LEAD lug (Lead to lead does not corrode as fast) That I think I leaned one time over the next many years. Put a new one in last spring (rig now 15 years old) so that one lasted 6 years)
That's my story and I'm scrapping it next week (Long story but I'm outta the RV life come the 14th)
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times