coach battery discharge

[kidagn]

2005 gulfstream vista cruiser (badged as Freightliner)
Continuing issue with coach battery discharging
Auto electrical shop says they can't duplicate.

I heard coach solenoid may be issue. Did notice touching it with metal object causes spark
Very frustrating... any suggestion?

[Tony Lee]

Have you got any figures to show how fast it is discharging - ie fully charge the battery and disconnect shore power and read the terminal voltage after say 2 hours, then read it every 12 hours from then on.
It is one thing if it takes 2 weeks, but entirely another if it takes a few hours.

Has it always done this or a new thing and if a new problem, has there been any changes made to any part of the 12V system recently
etc etc

[kidagn]

Thanks for responding. Shore power not involved. Example... yesterday was driving basically all day with short stops. Only had fridge on (and monoxide detector). Pulled over for night and within 20 min detector goes red and its alarm goes off. No coach power etc. Cranked engine and panel shows coach battery at complete charge. Detector back green etc. Normally if fridge left on the coach battery will die (known when detector alarm sounds soon after asleep!) But if fridge turned off.... no problem???
1st and 2nd coach batteries lasted 2yrs each. Then problem started. Couple of coach batteries went dead and replaced by autozone as they were under warranty.

["007"]

Welcome to irv2.
The house batteries will usually supply the 12v for control board of your refrigerator not the chassis engine batteries.
Here is a link explaining the power systems of your RV.
The battery cut off switch has to be on at all times you use your coach to keep batteries fully charged.
The alternator while your driving and the shore power cord when camping.
If you have a bank of four house batteries and you had two changed, the other two, one of them maybe defective and is drawing down power of all four.
All four house batteries should have been changed so they were all the same type.
Here is a link to describe what may happen when changing battery systems out if not careful.