How many cranking amps are you talking about? Will this exceed your BMS rating?
I have a button on the sprinter dash that links my house to the engine batteries. They used to both be lead acid, house is now LiFePO4 so i'm sure it'd trip my BMS.
Yes, I have multiple ways to top up batteries too. Recently I was in a situation where none was available. Unit wouldn't start. Had no tools. Not even a wrench or a multimeter. I knew the battery was new and fully charged so I figured it was something mechanical and called for a tow. Tow truck dude put a jumper on it and it started right up. Skip to the end of the story it was bad connections at the terminals. If I had just thought to wiggle the wires it would have started. I've sorted that out now. But it brought up the thought of what I, or more importantly my wife, would do if the battery really did die. I've been looking into the little miracle lithium things you can carry in your glove box. But the reviews on them are not inspiring. So that's how I come to the original question. In a pinch could I snag enough juice from the coach batteries to get it going? I looked at the chassis battery. 875 cca if that's the question you were asking. I have only a very tenuous grasp of the concepts but I think that means that I will NOT be asking the coach batteries to actually turn the starter. But they usually live around 13 to 14 A so maybe I could trickle the chassis battery for a while, disconnect and hope to have juice to start?
