New Perko Switch wiring issue

[CaptnMorgan]

Hey All....
So decided to add a secondary battery this year..
It seems pretty straight forward which I am fully capable
of...until I switch between 1 and 2 battery to find both are drawing power at the same time..

Heres what I've done..and found
1-starter Battery Positive
2-Accessory Battery Positive
common-Engine positive
Ground from engine to Batt 1 Negative


Now..If I take my final Neg Jumper between the 2 Negative terminals at the batteries and switch between both 1 and 2 on the switch, Both show continuity at the with full functions starter and Accesories.

But if I were to remove the jumper from the Negative terminals..Its seems to work as it should..??

Im confused....Any thoughts??

Thanks.

 

[Silvertip]

You are not measuring continuity -- you should be measuring VOLTAGE. It appears you have the switch and batteries wired properly and the switch is working as it should. In BAT 1, the engine will start and the engine will charge BAT 1. In BAT 2 the engine will also start and BAT 2 will charge. In BOTH the engine will also start and both batteries charge. As for the accessories, you can connect them to the ACCESSORY/HOUSE battery but they would remain active regardless of the switch position. If you connect them to the COM terminal, accessories will be powered in BAT 1, BAT 2 or BOTH and all juice is cut in the OFF position. You become the "electrical traffic cop" with this system because you determine which battery is being used, which battery is being charged, and which battery starts the engine and which battery is powering accessories. It is a very versatile system but if one is "switch-challenged" it can be confusing. There really is no need to use BOTH since most recreational boats don't have enough alternator output to charge two batteries at once. If the engine is properly tuned and the operator knows how to reliably start it, very little current is sucked from the START battery. In fact you could start the engine dozens of times before the start battery would begin to give up. It is the HOUSE battery that generally takes a beating so using the BAT 2 position for longer runs would direct alternator output to that battery. I think your wiring is correct but you misunderstand how the switch actually works. Look at it this way: In the BAT 1 position the entire boat operates as if BAT 1 is the only battery in the boat. In BAT 2 it acts like BAT 2 is the only battery in the boat. In BOTH it like you still have one battery but it is twice the size of either one alone.

 

[CaptnMorgan]

Im not sure if I unduratand your response..which is appreciated. Im referencing measuring continuity
showing that there is something seemingly wrong.

Again, when I have the jumper on between the batteries,
regardless of the switch in 1 or 2...Eveything is powered.
When I remove the Jumper..Switching from 1 and 2,
The switch functions drawing power from whichever
is selected..

 

[CaptnMorgan]

The more I read your response, the more I begin to better understand and realize I am switch challanged..

 

[Silvertip]

I guess I don't understand how you think the switch should work but it in fact is working as intended. When you disconnect the ground lead from the House battery, only battery 1 is delivering power but it is delivering power to everything as it should. When you reconnect the ground, you put the system back to normal and everything will work regardless what switch setting you have.

 

[CaptnMorgan]

I just assumed when switching between both 1 and 2 baterry
that say when on 1(start) I would only have start functions
and nothing accessory(house) would function.

And if on 2(accessory) then only my accessories would function.

But with your clarification...I get it now..After staring at my batteries for an hour wondering what I did wrong.

Thank you for helping me understand..Its much appreciated!