Which Cable for Battery Leads

[Stuart Giles]

Hi John

Just curious!  Why isolate the earth side?

I’ve always isolated the live side but I know there are arguments for both.

I've always understood that the thinking behind having the earth connection going through the isolator rather than the live is that a short circuit from one of the isolator terminals to earth won't cause an impressive firework display or electrical fire.

Re. battery cable I always use 25 sq mm welding cable like this:

https://www.ebay.co.uk/itm/Copper-Weldin...f2xFKWHN2A

25 sq mm cable has an outside diameter of about 12mm. If you get the cable from your local welding supplier, they will usually crimp the terminal lugs on for you while you wait. If you have a hydraulic press in your garage, making a press die to crimp the lugs yourself is a simple job.