When changing a car battery, why do you disconnect the negative first and then the positive, and vice versa when putting a new battery in? What will happen if you do it the opposite way?

Question

When changing a car battery, why do you disconnect the negative first and then the positive, and vice versa when putting a new battery in? What will happen if you do it the opposite way?

In: Engineering

Answer 1

So to answer the second half of the question, what will happen if you do it the opposite way… Unless you touch the positive terminal to something metal that’s grounded, absolutely nothing will happen. You’re breaking the circuitb either way. You can realistically take either cable off first and it won’t matter.

The idea of taking the ground off first is mostly just to prevent arcing if the positive terminal accidentally touches something. That’s it, plain and simple. Don’t over think it.