Battery Wiring

TopsulTime

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My '05 282 Sailfish has 2 battery switches and 3 batteries. 1 Battery is connected to one engine and the other 2 batteries are in parallel and connect to the other engine. All of the electrics/electronics are powered off the double battery. I have a couple of questions.

If either switch is switched to both does that connect all 3 batteries together? Or if I want all 3 connected to together do both switches have to be on both?

Why not re-wire so that 1 battery is dedicated to it's own engine (would still have the ability to switch to both if needed with one of the battery switches) and the 3rd battery would be house and all the electrics/electronics connect to it alone? Then the other battery switch would have the ability to connect this house battery to one of the engines if needed.

Battery 1 to engine 1

Battery 2 to engine 2

Battery 3 to house and one of the engine's aux changing cables connected to it



Would doing the above add any redundancy or protection or am I just overthinking this? It works fine as is but just want to be as safe as possible.



If my batteries are currently wired as described above, where are the aux charging cables for each engine likely to be? Ends taped up and secured somewhere???
 

Halfhitch

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It's generally considered good form to keep the house feed separate from a start circuit to avoid sags in voltage to your electronics while cranking. It depends some on how you use your boat. If you spend a fair amount of time in the boat with the engines off while using lights, radios, stereos, pumps and such then if it were me, I would have one battery do the starting duties for both engines (you only start one at a time) and have the other two batteries for the House duty. That way you have lots of storage for the house but if you ever need to do excessive cranking you can combine using these.
https://www.bluesea.com/products/products/5511e/e-Series_Dual_Circuit_Plus_Battery_Switch/featured
https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A
 

SkunkBoat

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My '05 282 Sailfish has 2 battery switches and 3 batteries. 1 Battery is connected to one engine and the other 2 batteries are in parallel and connect to the other engine. All of the electrics/electronics are powered off the double battery. I have a couple of questions.

If either switch is switched to both does that connect all 3 batteries together? Or if I want all 3 connected to together do both switches have to be on both?

Why not re-wire so that 1 battery is dedicated to it's own engine (would still have the ability to switch to both if needed with one of the battery switches) and the 3rd battery would be house and all the electrics/electronics connect to it alone? Then the other battery switch would have the ability to connect this house battery to one of the engines if needed.

Battery 1 to engine 1

Battery 2 to engine 2

Battery 3 to house and one of the engine's aux changing cables connected to it



Would doing the above add any redundancy or protection or am I just overthinking this? It works fine as is but just want to be as safe as possible.



If my batteries are currently wired as described above, where are the aux charging cables for each engine likely to be? Ends taped up and secured somewhere???
You might not even have aux cables connected in motor. Yamaha had a 3 wire motor start cable with two heavy gauge and one 10 gauge for aux. Look at your start cable and see if you have that.

Look thru the post I linked above. Similar to what you are trying to do. I added an additional House battery and separated the start batteries. Also added switches under gunnels so I don't have to open up hatches and remove plastic tubs.
 

dogdoc

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i agree house power should be isolated. if there is room leave parallel batteries in place and make them house then add another start battery. it is a good idea to keep batteries same age and capacity for longevity and charging. not hard to add aux wire if needed