[Richard]

You got me wondering, because honestly I never thought much about it.

I just went out and started my generator while watching the amp draw on the inverter panel. As best as I can tell it was just over 100 amps for just a blink plus the 10 amps I normally see when the batteries on float. I also put the clamp on ammeter on the batt cable at the house bank and registered 33 amps. I suspect the shunt on the battery monitoring system is more accurate and picked up the inrush current.

So if you have 3 of these cells (I think that is the number) then each cell BMS is going to see about 30 amps when cranking the gen. And if I read the literature correctly, each battery has 800 amps for 1 second on the BMS.

I am NOT trying to talk you into anything. Just providing data so you can make an informed decision.

If you do decide to cable back to the chassis battery side to crank the gen, PLEASE ensure that you do not inadvertently tie the chassis and house side together. There are two reasons. One your alternator may not like that. But more importantly. If you kill your house batteries you kill your chassis batteries at the same time, and have NO way of getting anything cranked to start the recharge process.

I personally like having the gen on the house batteries. If I goof and lose the chassis side, I can crank the gen, merge the banks, and eventually charge the chassis side enough to get going. I have had to do that twice when having an engine issue. If I kill the house side, then I can crank the engine, merge the batts long enough to crank the gen, and I am back in business. But this is personal preference. The same could be said for having the gen on the chassis batts. If you lose the chassis batts, merge, and crank the gen.