Solar Panel set-up

[Dolphin]

G'Day Shaun,
If I was going to charge only one battery I think it would be the start battery. Then when the engine is running you can charge the house battery.
The battery switch stops you discharging a battery by leaving a light on, which I have done, and found out later when I turned the switch on. Not having a switch may be the reason for your openeing statement viz "any battery on my boat seems to have a death wish, they only last 12 months".
Not using a regulator will use more water in the battery. The solar cell can tolerate the diodes as its open circuit votlage is about 18 volts. The two fuses are purely to protect the wiring. This is what I use on Felicite.
You should be able to check the leakage current from the battery by removing the battery terminal and connecting a milliampmeter between the terminal and the battery terminal lug. Remove the solar panel if you have one.
PS the seagull, and chip, is for you.
Greg.

[Shaun]

Thanks Greg for the drawing (with seagull & chip)

Your set up makes sense.
I'll look into the diodes & possibly a dual battery regulator maybe instead of the MPPT, The "Diodes" you have what are they called exactly? & where d'ya get 'em? , as there are i suspect probably millions of diodes available
cheers

[Phillip]

Shaun,

You will need a regulator for each battery otherwise one will always be draining to the other.

Phillip.

[Shaun]

Cheers Phil,
I have gone for one of these dual battery regulators,( apparently they keep each battery separated)
http://www.voosale.com/duo-battery-sola ... -dual.html
they are probably based on the diodes but in the one product,

& a 25w mono panel.

shaun