Electrical Design Advice

[Brett]

I'm trying to redo some of the electrical on the 27' SeaMaster. It has 4 Group 31 900cca batteries and three perko switches. Two perks switches are 1/2/both/off and one is on/off. Does the following schematic make sense. I'm trying to separate the house batteries from the starter batteries. Can I still connect all the negative terminals if one of the banks is in parallel and the other is not?

I think I have it designed so the engines can start off either starting battery or both. And the house will still get charged by the auxiliary charge cables from the engines. All the batteries will also get charged when plugged into shore power. I also bought a battery monitor for the house battery parallel bank (BMPro Battery Check) this is a shunt type device with bluetooth so I can monitor time remaining on my phone.

Any ideas would be appreciated.