Silas Carpy,
Don't fix what is not broken.
Here is what I would do in your shoes.
1. make sure there is power coming from the converter (or inverter charger) to the battery bank.
Do this by measuring the voltage at the bank, then plug in, wait a couple of minutes, and measure voltage again. If it has gone up--then bob's your uncle.
2. for the chassis battery add a trick-l-start. I've been using one for 8 years. No jumping needed even at temperatures in the -30 range.
3. Consider adding a modest solar charging system to the RV. Your battery bank will love you for it.