Between the invention of the self starter and the end of the 20th Century, the best portable car jump starters weren’t ...

Park the vehicle with a good battery in front of the one that needs a jump-start. Open the hoods on both cars, locate the batteries and remove the plastic covers on the terminals, if necessary.

That means that if you want to jump-start a dead battery with 500 CCA, you'll need to use a healthy battery with 500 CCA or more. You can technically jump-start a car battery using another 12-volt ...