The real question isnt so much how to bypass the issue, but eliminate it.
With that in mind. OP, lets try the easy stuff. Make sure you have a (preferably digital) multimeter.
Simple Battery Self Discharge Test
- Ensure entire battery bank is fully charged.
- Disconnect battery bank from coach
- Disconnect batteries from each other
- Measure the voltage on each battery. Identify the batteries and record each of their values.
- Return 24 or (and) 48 hours later. Record the values again.
If the values arent nearly identical, the batteries could be discharging each other, as one is weaker than the other(s). IF the batteries are basically at resting voltage, and within a small margin of each other, then you know that your batteries are holding charge, and you now should be looking for parasitic loads.
In my coach, the radio is run off the chassis battery. As are a few lights, my electric step, and I believe my slide and level jacks.
Any system you have attached and drawing from your chassis circuit could be causing your draw, including any frayed wire(s).
Next. The question is. Would you rather maintain the charge on the chassis battery, or eliminate your parasitic load? Either one should solve your problem, and the former could contribute to health and longevity of your battery bank.