bullet proof battery system

[jawz12]

all season long,i hear and see a common fault with people's boats.the batteries go dead while off shore,now what ??? the boost packs will not work if the battery{s} are really dead.
you should set your boat up with an isolated system,most smaller center consoles have the standard 3 position battery switches-the 1,2 "all" and off,these will not provide a seperation of the systems.what you need is to seperate the engine{s} from the 12v system,each system should run on it's own dedicated battery.if you've got 2 engines you should be running a 4 battery system,on a single engine setup you should have a 2 battery system.
for starting the engines,use starting batteries{duh} and use deep cycle batteries for the 12v system.use simple on/off switches,i use the blue seas switches.for a single engine,you will need 2 switches,1 is for the engine and the other is for the 12v system,pretty simple huh?? how do you recharge the battery ???? i use either the blue seas ACR,it's a sense relay,it senses voltage at each battery leg,when it hit the predetermined number,it grounds and allows bothe batteries to charge at the same time.some outboards have the ability to recharge multiple batteries.all these connections need to be made behind the battery switches-not at the batteries.
what this does,it allows you to be assured to have power to crank the engine,all the electronics are not drawing from the engine battery,this will also prevent your electronics "crashing" when you start the engine.the auto bilge pumps should have the "auto" feed line hooked behind the battery switches-2 batteries 2 pumps,this assures that at least 1 pump is "hot" at all times..for a "parallel" i use a "merc" style starter relay-they're sealed and stainless steel backed-this needs to be connected behind the battery switches as well...
twin engines are a little more complicated...if you need some more info about this,it's a great off season project,should take you 1 day to set it all up...drop me a line at jimmysmarineservice@comcast.net

[WAHOONBOX]

SON!!! WHAT WE HAVE HERE LADIES AND GENTLEMEN IS AN ELECTRICAL GHURU!!! I'M IMPRESSED! FOR I AM ONE DUMBASS WHEN IT COMES TO THE MECHANICS

AWESOME POST TO SAY THE LEAST! THANKS FOR SHARING A TIP FOR ONE OF THE MOST COMMON REASONS WE DO NOT GO FISHING...

[Double D]

I would be interested in hearing more about the 2 engine set up....

For the past 2 years, I have some mystery issue with my electrical system. Changed batteries, changed charger, rewired a bunch of stuff including the genny, but I still have low charge issues. Oh, and the crashing electronics....

While I can usually handle the mechanical end, I am an electrical dummy

Thanks bro!

[Sea Draggin]

In my limited experience with my own old boat, crashing electronics have always been a symptom of low voltage.

Two engines, two switches and two or four batteries and I would hedge a bet that it is just wired wrong.

Maybe only charging on #two, not #one or something like that if crashing while motor is running.

Do what I do, suck it up and take it to someone who knows what they are doing.

[Double D]

Do what I do, suck it and take it to someone who knows what they are doing.

Agree, if I can't figure it out, bring in a pro When I find the right guy, I'll turn him loose.

P.S. I assume you meant "suck it UP"

[matey1]

Definitely crashing electronics upon starting your engine/s is a sign that the batteries have low voltage and are very close to going south. i have a single engine with the switch that jimmy mentions. what i do is run out to where i am going with it on 'both'. this assures both are fully charged after the long ride out to the fishing area. when i shut off the engine. sometimes i oly shut it down for a sec to change the switch over to '1' or '2'. never turn the switch with the engine running. especially if it is an outboard as this can cause serious problems. this assures me i always have one fully charged battery ready to roll. when time to go in i shut the engine down once more and switch back to 'both' and charge away on the way in.