How do I charge a car battery outside the car with a portable car charger?

I'm not sure what to do with the negative wire. The instructions say to put it on a metal piece of the inside of the engine to ground it. But the instrutionsa also say that if the battery is not in the car to use a long wire and connect the negative to that wire? I'm confused.Can't I just put the negative on the negative of the battery directly?How do I charge a car battery outside the car with a portable car charger?
yes just hook the positive to positive negative to negative on battery all will be fine



Turn on battery charger after it is hooked up shut it off before disconnectingHow do I charge a car battery outside the car with a portable car charger?
they try to make it safer...by not hooking neg to battery directly...just hook up pos to pos,,,neg to neg then turn on charger [plug it in] just keep your face away from battery in case spark blows it up,,,about a 1 in a 20 million chance but it could theoretically happen.How do I charge a car battery outside the car with a portable car charger?
u just put the red to plus and black to minus plug in the wall switch on way to go don't 4get to loosen the plastic caps across the top of the battery if it has them or u will get a pressure build up from the heating gas