Best system for the job

[BobWhite]

Wondering if anyone has a thought of the best panel for the area allowed, the space is 116" by 85" and I am looking the get the most power I can from flat laying panels on a twelve volt system. There shouldn't be any shading.

Actually I am looking at the hole system to charge three AGM deker 8d batteries on a pleasure boat. I was thinking (3) solar world 280W 60 cell Monocrystalline Solar Panel or (3) of the solar word 315W 72 cell Monocrystalline Solar Panel that I would need to squeeze an outher 1.5" I think from somewhere. Combined with a Classic 150 and wizbang Jr. A trimetric to monitor two house batteries and one engine battery's voltage. This isn't all I would consider, just throwing out thoughts.

Problem: can I charge the engine battery threw an isolator setting the classic to charge the house batteries? I know it won't see the battery so it won't charge it correctly! Or should I use two panels for the house batteries on a classic and one for the engine battery by adding the MNKID? If I throw in the kid what will happen when the engine is running, that would buck the alternator wouldn't it?

[mike90045]

switching the Classic from battery to battery, may glitch it and cause a reset, and it may loose it's settings if it's internal battery gets too low.

[BobWhite]

Thank you mike90045, I'm not looking to switch it but feed threw an isolator so that it won't feed back from the engin's alternator if the boat is under way, To the house batteries that is. Maybe I'm making it to complicated but would like to maintain the starting battery also without making the system to complex. I'll see if I can draw up a diagram.

[EEbersol]

Bob white
I think the most simple way would be to use a normally close relay that is opened by the current from the engine ignition

Also I think the second option you mentioned with the KID is a great idea and you have no reason to be concerned about the two charging sources fighting, when the alternator is running the KID will most likely stop charging because  it sees battery state of charge by voltage and does not care how it got there

[BobWhite]

Thank you EEbersol,
The relay does sound reasonable and will chew on that idea a bit! I do keep thinking of the kid but would loose the benefit of one panel on the house batteries when sitting on a mooring for a week or so in overcast weather when it is needed the most.
Walt