Appreciate the concern, I'll ignore the incorrect assumptions. I'll have them test it at the RV dealership as well as when I take it into Mercedes next month for it's service. Could be a defective battery - or a small draw even with disconnects. I remember when I first got this MH, very cold start one morning and it ran like my old Kubota used to until it warmed up in sub zero temps. And a few times since, when in storage for a few weeks it ran rough for a few minutes even in warm temps. Considered it more of a diesel problem than a battery problem. Frankly I don't really care for the Sprinter Chassis. It rides nice, but it's a little anemic on power when towing and does some weird electrical stuff periodically - alerts for no reason while driving etc. .
That’s not a battery problem. Really Cold and diesel = potential hard starts and running lumpy until the cylinders heat up enough to have complete combustion.
If it operated the cold start stuff (grid heater or glow plugs) and also had enough juice to spin a frozen diesel, the battery is just fine.
Also not a likely cause of running rough when warm. Especially a diesel since they draw very little power to keep the engine running vs a spark ignition engine.
I hope my “incorrect” assumptions helped you since you made no mention of diagnosing the likelihood of a parasitic power draw on the chassis side until it was mentioned.
