choosing battery cable size question

[bob johnson]

I went through the search function and couldnt really find an answer.

I am building my electrical system from scratch, I bought a tiller model boat and am doing some refurbishing and adding a center console.

I have run hosing to carry my wiring, and made an order to a distributor that carrys a lot of electrical stuff..

while i had originally wanted to have two batteries in case one went dead or wasnt powereful enough on those really cold mornings after i hadnt charged the main battery recently enough....( I will use my boat in salt water in temps below 0 F)
I am thinking now to just buy one really big dual purpose battery for starting and running my equipment and guages .

the facts:
1997 evinrude 90 hp ocean pro outboard
11 foot run of wire from center console mounted battery to the outboard connection

I have ordered 25 foot rolls of #6 awg battery cable from the distributor

one red one black to cut my cables from


MAIN QUESTION
is this cable too small?

I can send it back and re order if need be...


secondary question might be...is this a good idea to use one big battery?

what I have to run will be a hydraulic jack plate
the motor has power tilt and trim
I will install a socket for a part time hand held spot light
I will have a fish finder
I will have nav lights
I will have cabin lights
I will have two seperately wire bilge pumps( 1000 gph each)

most of the time i will run the jack and or tilt and trim while the motor is running

maybe at the ramp I will run the tilt ansd trim with the motor off( dont know if it matters though)

thanks hope everyone is having a nice mermorial weekend

bob

 

[Chris1956]

Re: choosing battery cable size question

I think 6AWG is too small. I would go with 2AWG, since you have an 11 foot run and a cold morning. it only costs a few $$ more, and is much better.

 

[flargin]

Re: choosing battery cable size question

I think 6AWG is too small. I would go with 2AWG, since you have an 11 foot run and a cold morning. it only costs a few $$ more, and is much better.

Good choice would be 2 or smaller...

6AWG is 9% drop
2 is 3% drop


Check out the calculator at the bottom of the page: http://www.gadgetjq.com/wiring_size_guide.htm

 

[bob johnson]

Re: choosing battery cable size question

update:

I went to the marine mechanic/store where i used to get my older motor serviced. old cranky, but giood hearted guy....ben doing it for like 30 years or more.

he sold me the dual wire battery cable line for my older boat...

he didnt have the dual line in anything over #4.

I told him i wanted 1/0 and he said i must be nuts!!!

he knows the motor and the distance , and he looked up OMC,s info from 2004. they offered a 124" long battery cables with ends in #4 wire and said it fit 150-225 HP applications!!!

thats almost 10.5 feet!! and a much bigger set of motors than the 90 I have!!

I bought #2 tinned from him..it is huge...it should be fine.

the trick will be getting into the motor through the opening they have and snaking it down inside the cowl!! not a lot of room!!

next up picking a battery dual purpose with lots of cold cranking power and as much reserve as i can get...

thanks

bob

 

[dan t.]

Re: choosing battery cable size question

basic rule for DC wiring: There is no such thing as too big of wire,I like welding cable, nice and flexable

 

[flargin]

Re: choosing battery cable size question

I like welding cable, nice and flexable

Nice idea. Thx

 

[bob johnson]

Re: choosing battery cable size question

basic rule for DC wiring: There is no such thing as too big of wire,I like welding cable, nice and flexable

I had thought about that, but since my boat use is mostly in salt water I wanted tinned wire all over that boat.
bob