Questions About A Dual Engine, Dual Battery Station with a Solar Panel

[San_Diego_SeaRay]

I?m gutting and re-wiring a 27ft 1982 Sea Ray Sundancer 270. Was briefly researching options available to me to overcome the charging and functioning challenges of having twin engines, a dual battery system with a solar panel. I drew up the attached diagram as an illustration of what I was thinking.




Questions:

1. How do you wire two Alternators to charge batteries? They would be Delco 10si alternators. How does the sense wire work in this configuration?
2. In my diagram I am relying on a Dual Sensing VSR to first charge the START battery, then at 13.3 volts it would close and start charging the AUX battery. Do you see any problems with my setup? I?m thinking that once the VSR solenoid closes, the Alternators will (once again) start detecting a deficiency and will output add?l current to charge the AUX bank?
3. Since it?s a Dual Sensing VSR, it?s supposed to also close if it detects 13.3 volts on either side. So I?m thinking that when the boat is in storage, and the Solar Panel is charging the AUX battery, if it can boost the voltage up to 13.3 volts, then the VSR will close and the Solar Panel will also start to charge the START battery as well. Am I correct in this assumption?

For the record, here?s the loads expected for each battery bank, as well as I can remember at the moment:

• Starting Battery:
  • Engine including starter
  • Bilge lights
  • Trim tabs
  • Trim rams
  • 900 watt windlass (will only be turned on when engines are running)
• Auxiliary Battery:
  • Deck lights
  • Bilge pump/switch
  • Marine Radio #1
  • Marine Radio #2
  • Fishfinder/GPS
  • Fishfinder Transducer
  • NMEA 2000 network
  • Stereo
  • Deck lights
  • Nav Lights
  • Cabin Lights
  • Macerator pump
  • Water Pump
  • Holding tank pump
  • Underwater lights
  • Inveter

My typical scenario would be to run the boat appx 20 - 50 miles roundtrip on a weekend, then let the boat sit for 1 to 2 weeks. The engine would probably be running less than 25% of the time for each outing, which would normally be about 6 hours. The times the engine is not running will still use a lot of AUX battery with things like the stereo, radio, lights, GPS, etc. I would like the solar panel to fully recharge at minimum the AUX batteries and hopefully keep the START batteries charged as well.

Do you see any flaws in my setup? What would you do differently and why?