Charging a battery

I screwed up. When I hooked up an electric charger to the battery, I out the + on the red and the - on the black. Unfortunately, I was supposed to hook the black on the grounding bar.

How bad is this? I had it hooked up for about 20 minutes before I realized my mistake

I’m hoping I haven’t damaged the electrical system.


If the red was on the positive battery terminal and the black was on the negative terminal you’ve done no damage.

Yes, you should hook the black to something other than the battery terminal, but since the battery didn’t explode I guess you’re OK.

Lucky, but OK.

Don’t do it again.

How old is the battery and why do you need to charge it?

You can almost always (i.e. every time) get away with that. Don’t worry about it. That’s considered bad advice, but it’s true.

That is good advice, and should be followed, but it is not critical under normal conditions. Any problems, if any would appear as you hooked it up or disconnected it.

I assume that the reason you connect the black cable elsewhere is the same as when jump-starting a battery, which is to avoid a spark next to the battery that could cause it to explode. If it didn’t explode, then you didn’t damage anything.

Ah, bless you all. This is indeed good news. I’ll sleep well tonight. The battery is old, ready for a replacement.

If you leave the battery charger unplugged while you attach the clamps to the battery, and you hook the red clamp to the positive post and the black to the negative post, you won’t have any problem. There is no power until you plug the charger in, so you won’t get a spark. With jumper cables, it is different. The power from the donor battery is present, so you might get a spark when you connect the cables. This spark might ignite the hydrogen gas at the battery and cause an explosion. However, what you did with your charger, as long as it wsn’t plugged in when you attached the battery clamps, poses no hazzard.