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Best way to wire up twin engine, house battery bank, with Blue Sea Autocharging Relay > Best way to wire up twin engine, house battery bank, with Blue Sea Autocharging Relay
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Best way to wire up twin engine, house battery bank, with Blue Sea Autocharging Relay


Old 08-27-2017, 03:26 PM
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Default Best way to wire up twin engine, house battery bank, with Blue Sea Autocharging Relay

Trying to figure how this should be wired up, adding two group 31s as house bank. I want it to connect to the #1 battery (port) when charging

Using http://assets.bluesea.com/files/reso.../990310020.pdf
Instructions: http://assets.bluesea.com/files/reso.../990310020.pdf

Typical twin engine twin switch dual battery original set up something like this Im assuming: https://www.perko.com/images/catalog...(8500INS1).pdf

Right now, my port switch has to be on 1, 2 or both fro 12v stuff to work off the panel. So there must be cable from switch panel in cabin to that port battery switch COM terminal. This would need to be taken off and ran to the Blue Sea 1,2,combine switch (on its #1 circuit) and then to house batteries I believe. Whats throwing me for a bit of a loop is what to do on the #2 side of that switch. it shows it going between starter power feed and the existing #1/port battery. That would mean taking off the current starter to port side bat switch lead and running that all the way in, then all the way back out to something - but then it can only get power from those batteries, never being able to switch to the starboard #2 engine bat. Im thinking leave the port and starboard switches alone, add a line from the #1 battery terminal port switch and run that to one of the #2 terminals on the blue sea switch up front. ***Edit - I wouldnt have to run a line all the way back. Put a terminal block under the galley fed from port #1 battery, have one lead run to SI-ACR relay, and the other lead to combine switch*** That way, in a emergency situation say the original #1 engine battery was weak you can put the blue sea switch in combine and it will force connection to the house bank (wont be connected through ACR circuit because not charging) This would leave one of the Blue Seal switch #2 terminals unused.

Does this seem like it would work? Should leave current port and starboard battery switch operating as they are currently, and if we are on battery power for long I can hit the combine on Blue Sea switch and it will use the 2x group31 house bank AND port #1 engine battery. Keep the port rear switch on 1, even if we killed all 3 of those batteries, could start each motor by putting them on #2 starboard battery and firing them up one at a time.

Anything Im missing/not considering?

Last edited by GrannySShifting; 08-27-2017 at 03:30 PM.
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Old 08-28-2017, 11:00 AM
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I wired mine the same as the instructions show....

I really didn't want or need to combine my house battery with my starting batteries, as I had my charger on whenever we were out of the water.
- starting batteries (cranking battery)
- house battery (deep cycle)

it's a very simple hookup. On my (old) Fountain, I had 1 wire from house breaker panel that connected to one of the battery switches. I just took that off of that terminal and placed on the terminal for the Blue Seas battery switch.
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