Patrol 4x4 - Nissan Patrol Forum banner
1 - 7 of 7 Posts

·
Registered
nissan
Joined
·
126 Posts
Discussion Starter · #1 ·
Hi guys I’ve been given this kings 12v control box and I’m wondering what size cable to run from the start battery to the box. The second battery will only be maybe 600 from the box
Thanks in advance
Ron
Automotive tire Font Circuit component Gas Motor vehicle
 

·
Registered
1988 Maverick TD42,
Joined
·
251 Posts
Assuming it's about a 5m run and that is a 25A charger (which will pull up to 35A), go for 25mm2 (4awg) and fuse it at 100A. If you require the ability to "assist" the main battery if it's too low to start, go for 50mm2 and fuse at 250A (may not be a good idea if you are running a Lithium batterie)

Tips
  • Use ANL fuses, stay away from Chinese resettable breakers.
  • Make sure to get copper cable, not copper coated aluminium.
  • Welding wire is a good choice as it's often well priced and has good insulation.
  • Remember to fuse between charger and aux battery too.

If you want to save some coin on cable, you can get away with 16mm2 and fuse it at 60A.
 

·
Registered
nissan
Joined
·
126 Posts
Discussion Starter · #4 ·
Thanks Seth.jxl and gq bush man.
I put the 100amp fuse as close to the starting battery? And should I run an earth from the starter to the back or can I just earth it in the back somewhere. Also would you put a 50amp fuse between the charger and the auxiliary
Thanks
Ron
 

·
Administrator
Y2KGUII ZD Wgn
Joined
·
50,103 Posts
Agree with Seth, 4awg wire minimum, I did mine in 6awg like an Irish man (to be sure to be sure) ;). I did it in twin core so the earth went back to the battery and not just to body somewhere.
 

·
Registered
2007 GU & 2016 GU
Joined
·
59 Posts
Ensure that your cables, especially the battery plus, is not getting damaged due to sharp edges of body parts on the insulation.
Chaffing, rubbing,cutting through the insulation. Might not be the case during installation, but further down the road due to vibration. Its a fire hazard.
 

·
Registered
1988 Maverick TD42,
Joined
·
251 Posts
Thanks Seth.jxl and gq bush man.
I put the 100amp fuse as close to the starting battery? And should I run an earth from the starter to the back or can I just earth it in the back somewhere. Also would you put a 50amp fuse between the charger and the auxiliary
Thanks
Ron
Hi Ron,

The fuse is there to protect the cable, not the device(s). With that in mind, you can wire the charger direct to the battery if it is very close (say 20cm), if not, fuse it at what the cable is rated to.
There is no issue using the body as ground, provided the ground cable from your aux battery and your main battery exceed the rating of the fuse on the V+ side (in your case 100a). You should ensure that your ground cables at both ends have good connection to bare metal of the car body and its a good idea to cover them with silicone to prevent corrosion.

Cheers.
 
1 - 7 of 7 Posts
Top