Wire size

[wiggy]

Have just fitted (well almost) a 20A battery charger, what size wire should I run to battery that is about 1.5m away?

 

[pvb]

As large as possible...

As large as possible (within reason) so as to minimise voltage drop and heating of cables. As a minimum, I'd go for 10 sq mm.

 

[Honey]

Try this site for calculations!
http://www.unlimited-power.co.uk/cable_sizing.html

 

[SvenglishTommy]

I would also go for 10mm2(AWG 8) that will give you a voltage drop of less than 0.5% (0.05V), although 6mm2(AWG 8 or 9 ) would be fine if you have some available. Only for charging though, for any other application 2.5mm2 would be fine.

 

[pvb]

[ QUOTE ]
I would also go for 10mm2(AWG 8) that will give you a voltage drop of less than 0.5% (0.05V)...

[/ QUOTE ]Pleased that you agree that 10 sq mm is a good choice, but I'm afraid your voltage drop calculation is wrong. When calculating voltage drop, you need to consider the entire circuit - there and back - so you're looking at 3m of wire, and the drop would be around 1% (0.1V).

 

[SvenglishTommy]

Yes, you are quite right. It is the distance from the source and back again. Silly mistake as I was using my own wire size calculator which clearly states this /forums/images/graemlins/smile.gif