Power for electronics

[jet2go]

I have a dual battery setup on my inboard jet, with the standard "off, 1, both, 2" battery isolator switch. If I don't have the switch to the both position, my electronics shut off everytime I fire up the big engine. I replaced the wire from the common leg of the switch up to my dash with #4 marine wire (positive and ground), hoping that would help, but it didn't make any difference.

Are the main wires I have running from my batteries to the switch too small, causing a voltage drop during cranking?

[ISeeFish]

Was having the same problem, ran starting battery to 1 on Perko and Deep Cycle battery to 2. Ran all electronics to Deep Cycle and normally run Perko on position 1.

[fishkisser]

Originally Posted by jet2go

I have a dual battery setup on my inboard jet, with the standard "off, 1, both, 2" battery isolator switch. If I don't have the switch to the both position, my electronics shut off everytime I fire up the big engine. I replaced the wire from the common leg of the switch up to my dash with #4 marine wire (positive and ground), hoping that would help, but it didn't make any difference.

Are the main wires I have running from my batteries to the switch too small, causing a voltage drop during cranking?

Yes ...

[flyingd]

Unless the key shuts off all power to accessories when starting, like in a car. You will have to make sure the power you are geting for your electronics is not on that keyed line.

[cutbait]

I work on boats you could live on and we had the same problem on engine start up,until the manufacturer put in a dedicated house set that the engines did not pull off to start.On start up you get a drop then a spike which dumps the electronics.what Iseefish said is just that,he is running electronics off of a battery that is not tied into the start batt.***.1 ***.2 is (house) batt. But to charge while underway sw.would need to be in both position.MOST battery switches maintain connections between 1-both-2 check on your particular switch before switching with eng.running.Hope this helps.

[Boats]

I had a similar issue on my boat.
Setup: Twin outboards and two batteries tied to a Perko switch.
If I ran any electronics with the engines off... I had to put the switch in the "both" position to start my engines. (Not a safe situation!)

My solution:
I installed a special battery bank switch made by BEP Marine and added a "House" battery. All three batteries are Yellow Top Optimas.

The BEP switch isolates each battery.
Electronics can only draw down the "House" battery.
Starboard engine can only draw down the starboard battery.
Port engine can only draw down the port engine.

There is also and Emergency position to run them in parallel.

The isolator also allows either engine to charge any of the batteries.

Switch was somewhat expensive, as were the batteries, but a "must have" in terms of safety IMHO.

I'll post a picture later.

Boats