Battery Cable - What Gauge?

[83Evinrude]

I'm installing a battery disconnect switch in my Negative battery cable. The original Positive and Negative cable say 4ga on them and are about 3ft long each.

Where I'm mounting the switch, will mean the Negative cable will increase in length to about 11-12ft. Should the gauge of wire I use be increased, and if so what should I use?

The boat is in my signature, thanks for all opinions.

 

[bear_69cuda]

Re: Battery Cable - What Gauge?

I would run 0 AWG wire for that distance. I'd also scrap the 4 AWG and get 0 AWG from the switch to the motor. Greg has helped me with all the wiring on my last two boats. Check him out! http://gregsmarinewiresupply.com/

 

[haulnazz15]

Re: Battery Cable - What Gauge?

I would also recommend 0/1 gauge as long as you can make any necessary bends.

 

[83Evinrude]

Re: Battery Cable - What Gauge?

Does anyone know how many amps are required to start a 5.0-5.7L V8 engine?

 

[Friscoboater]

Re: Battery Cable - What Gauge?

I am in the electronics biz and you need to use 0 or 1 gauge.

 

[83Evinrude]

Re: Battery Cable - What Gauge?

Thanks for the responses,

The Welding cable sounds good, and since the boat is only used in fresh water it can be used instead of tinned marine cable?

Is there any difference between putting the switch in the negative line instead of the positive? That way if anything ever touched the switch terminals (on back) it couldn't cause a short to ground.

The disconnect switch I have is a Bep Marine thats rated for 1250A Cranking and 275A Continuous. I'm assuming that will be enough for my purpose?

 

[cr2k]

Re: Battery Cable - What Gauge?

If it got switched OFF with the engine running (alt putting out current) the current WILL find somewhere to go. This could be costly. Other then that go for it.

 

[83Evinrude]

Re: Battery Cable - What Gauge?

If it got switched OFF with the engine running (alt putting out current) the current WILL find somewhere to go.

This would not be the case if the switch was placed in the Positive cable line?

I believe the multiple battery type switches disconnect the alternator during switching but this one is a simple on/off type for one battery only.

 

[jhebert]

Re: Battery Cable - What Gauge?

I'm installing a battery disconnect switch in my Negative battery cable.

Installing a disconnect in the negative circuit of the primary battery distribution is not a good idea. Install the disconnect in the positive branch of the circuit.