Electrical question.

[barryassheton]

Hi,

At the end of the year I will be re-wiring my boat so I need to start making sure I know where I am going with it. All the old wiring was ripped out last year as most was out dated and didn't make much sense so starting from scratch. The positive is not a problem, well not at the moment lol, my problem is the negative as there are so many different opinions on it.

I will be running my negative from the fuse box (The fuse box has a built in neg and pos bus bar) to another bus bar where it will meet any other negatives that cant go through the fuse box, this will then go to a main heavy duty Bus bar and this is where I am getting conflictions.

I have 2 crank batteries (twin engines) and 1 twin battery bank (deep cycle) and a port and starboard anode.

Do I connect the negative terminals on the batteries and the anodes to the engine blocks then to the bus bar or do I connect all negatives, engines blocks and anodes straight to the bus bar.

Thanks

 

[Baddox]

Connect the battery negative terminals together and then on to the engines. You'll need heavy duty cable from that, the size depends on the length of cable run and size of starter motor. In the USA it is usual to fit an isolator switch in both + and -ve cables from the batteries. European installations often only use an isolator in the +ve.
Some installations run the +ve from the battery to starter motor solenoid then on to the alternator.. Others have a dedicated + and -ve wires from the alternator back to the battery; a split charge diode or Voltage Sensitive Relay set-up in this line is a good idea.
The cable to the bus bar and fuse box can be lead to the batteries via the isolator switch.

 

[barryassheton]

Connect the battery negative terminals together and then on to the engines. You'll need heavy duty cable from that, the size depends on the length of cable run and size of starter motor. In the USA it is usual to fit an isolator switch in both + and -ve cables from the batteries. European installations often only use an isolator in the +ve.
Some installations run the +ve from the battery to starter motor solenoid then on to the alternator.. Others have a dedicated + and -ve wires from the alternator back to the battery; a split charge diode or Voltage Sensitive Relay set-up in this line is a good idea.
The cable to the bus bar and fuse box can be lead to the batteries via the isolator switch.

Thanks, My plan is to have the isolator switch in the +ve line and I will have a split charge diode ( 2 alternators to charge 3 batteries). So all batteries to the engines and do I then connect the engines to the anodes and the anodes to the negative bus bar or do I connect the engines and the anodes straight to the bus bar.

Thanks