Help with start battery intallation

[Air Mobility]

I bought hull 158 about a year ago and I'm in the process of installing a dedicated start battery. I plan to use the system Longhawk used that issolates the house and start banks. I will use the Balmar Duo Charger to keep both banks charged.
I removed the cable connecting the 1/2/both switch from the engine on/off switch. (both under the nav table) I connected a cable from the new start battery pos tenminal to the engine on/off switch. This will isolate both systems.(the house from the start)

The problem I encountered today has to do with the output of the alternator. It appears that the output of the alt goes to the starter and then back to the engine on/off swich via the 1/0 cable. In the original system the current then flowed back to the 1/2/both switch and finally to the batteries. When I separated the 1/2/both switch from the engine on/off switch, I blocked the flow of current to the house batteries. If I make no further modifications, the alternator will only charge the start battery. The only way to charge the house bank is with shore power. I want the alt and shore battery charger to charge the house bank and use it, via the Duo Charger, to charge the start battery.

My question(if you are still with me) is am I correct in my assesment of the system as it stands? Can I make the output of the alternator the house bank by adding a direct connection with a number 10 wire?

If anyone can help with these questions, e-mail me your phone number so we can talk or add to this string.

Thanks

[R.B.]

From what I have read and seen on boat wiring diagrams, you want the alternator to be connected to the house bank directly. This will eliminate the chance of switching or not having the 1/2/both switch turned off and the regulator on the alternator getting fried. In this configuration your alternator will always be charging the house bank which is what you want.

Here is a link to Catalina 34 web site with a diagram with wiring sizes:

http://www.c34.org/projects/images/Cata ... ematic.pdf

[LONGHAWK]

Yes, it is best to connect the alternator output to the house system
Longhawk #173