Disconnect battery when welding on car? Some say dont!

Jul 15, 2017
Hello friends,

I read many different opinions on this topic on the internet and since my cars are full of complex electronic I am quite concerned.

  • Some say to put a device on the battery (special device for welding) and leave the battery connected.
  • Some say to just leave the battery connected and do nothing about it. (also no device on there)
  • Some say to disconnect the battery. The strange thing on this method is that I have read that computers can get damaged/fried through the ground which is always connected to the car, even without connecting the battery. I have no clue how to look at this or how to understand the way damage may be caused but I see more then one topic about this on the internet.

What is the most safest way when there is some welding to be done on the car? (When the welded part cant be separated from the car ofcourse)
Agree with the above - ground as close as feasible to your work... I've never disco'ed the bat and never had issues, however, ymmv.
I wish I had a definite answer and a reason but the frame welder that welded my hitch on said that putting the welder ground close to the actual weld would prevent any damage to the electronics.
I'm guessing the reasoning would be that the electrical current will seek the easiest (lowest resistance) ground path. You don't want it finding parallel paths through the electronics to ground, which it might if the electronics were between the welding location and the ground.
Ohms law says the current will use all available paths, but the majority goes through the path of least resistance.

Make sure the ground electrode is the only good ground I'd say.
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