TIL my answer to a simple question about car batteries was totally off

I was helping a friend jump his car in his driveway last month and I told him to connect the negative cable to the dead battery's negative terminal. It sparked like crazy and we had to stop. I looked it up right after and you're supposed to connect the last clamp to a bare metal spot on the engine block, not the battery itself. Has anyone else made a basic mistake like that and had to fix it fast?

2 comments

2 Comments

simonmoore2mo ago

Honestly that sparking is a serious warning sign people miss. You basically created a direct path for hydrogen gas to ignite. Modern batteries vent that stuff constantly, especially when they're struggling. The engine block ground is safer because it's away from those fumes. I've seen battery cases crack open from a smaller spark than what you described.

coleman.jamie2mo ago

Man, I always thought that spark was just a normal part of connecting a battery. How wrong was I? Your point about the fumes venting constantly really clicked for me. I'm definitely going to the engine block from now on.