Kevin,

I just purchased this boat and the surveyor indicated the existing 10 amp, 1 bank charger was not suitable for marine use. So I purchased a marine 3 bank 15 amp charger (Canadian Tire Nautilus). Apparently every 5 minutes, it cycles through each bank and sends up to 15 amps.

• I connected one bank directly to Battery #3
• I connected second bank to post #1 on isolator
• I connected third bank to post #2 on isolator

Do you believe that this will work?

Shawn

Shawn,

The posts should not be connected inside the isolator.

A one in / three out isolator has 3 diodes inside. Internally, one goes from Post A to Post 1, the next from Post A to Post 2, and the last from Post A to Post 3.

When the alternator starts charging, it applies charge to the battery with the lowest voltage first. When that voltage rises to the second highest, the isolator allows current to flow to the lowest 2 batteries. When the combined voltage hits the voltage level of the highest voltage battery, the isolator allows current to flow to all 3 batteries. Usually this happens within seconds of engine startup.

The only time Posts 1,2, and 3 are basically connected is when the alternator is operating and the batteries are all at the same voltage.

Hope this helps,

Kevin

Kevin,

Please check out this drawing of my boat wiring.

So are posts 1, 2 and 3 basically connected on an isolator?

In other words, when the charger is sending power to bank #1 to charge, is it also going to post #2 and #3 ? I seem to have continuity between post 1, 2 and 3 on the isolator

Shawn

Hi Shawn,

Nice boat wiring diagram!

This will work great. If it cleans up your wiring and makes battery removal easier, I would consider connecting the bank for battery #3 to the isolator post 3.

Have a great weekend,

Kevin