So just to update everyone: I'm a newbie idiot [emoji1751]
The chassis battery was low due to the "normal" parasitic drain that's pretty common in the sprinter. Been starting it every other day or so, and it's been fine.
The house battery was the one I originally was referring to, even though it clearly says "house" and "chassis", I guess I didn't pay enough attention.
Appreciate all the replies, we're actually at an RV park for the first time with it, and so far so good [emoji106]
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