View Full Version : Battery wire size ?
Joker2
05-01-2010, 05:39 AM
I have a question about wiring up my batteries. I can get a hold of 2/0 or #2 wire for free. Chemical and gas resistant. I was thinking of using this to run from my dual battery switch to my batteries. This wire is stranded but not stranded with as thin as the marine grade wire which I know is more flexible. I don't need flexibilty for the run I'm doing. I will use the marine cable to the motor ( outboard )though. As far as current capacity, I'm assuming there is no differrence. Does anyone have thoughts ? Thanks
Destroyer
05-01-2010, 07:28 AM
Without getting too technical, the max amps for wiring a chassis (Very very conservative figure ) for that wire is 181 amps. Your power drop, assuming a 20 foot run, 12 volts and 100 amp load would be about 0.32v or, put another way, the voltage would be 11.68 volts on the other end of the circuit. In careful engineering the voltage drop, insulation temperature limit, thickness, thermal conductivity, and air convection and temperature should all be taken into account but are not relative here.
 
To answer your question, the thicker the copper strands the more brittle and less flexible, but 2/0 AWG (American Wire Gauge) is still 2/0 AWG. Presuming both are copper there is no difference.
spareparts
05-01-2010, 07:38 AM
#2 should be fine for an outboard that doesn't use a computer, but if you can get it for free, might as well use the 2/0.
macojoe
05-01-2010, 08:12 AM
I just ran 4 gauge marine tined wire 20 ft in my boat and it works great!!  I use to lose so much power when using the trim tabs that the low voltage warning use to go off on my fish finder and GPS, No more.
And if I read this right you are just going from the switch to the battery's so its not going to be long at all, You should be fine
http://www.wellcraftv20.com/gallery/albums/album218/024_G.sized.jpg
Joker2
05-01-2010, 04:09 PM
Thanks guys you helped me make my decision
bradford
05-02-2010, 10:42 AM
Hey Joker, how bout commin' off some of dat free 2/0?!
SkunkBoat
05-03-2010, 06:54 PM
http://www.uscgboating.org/regulations/boatbuilder_s_handbook/electrical_part3q.aspx
 
This link may help when wondering if you are doing something wrong.
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