Imported goods like car batteries are difficult to get hold of here. After half a day trying to find somewhere that sold a battery of the right size and specifications that hadn't already gone flat on the shelf, I got it home and, before fitting it, noticed that it was the opposite way around to what I expected - positive on the front left, negative on the front right.

I didn't even know they made batteries like this, so I never thought to check.

I fitted it turned around, so that the positive connected to positive and negative to negative.

enter image description here

It seems to work fine, it's just rotated 180 degrees and I had to adjust the terminals to get them to fit.

enter image description here

Is there any problem with having it fitted like this, or precaution I should take? Possibly overthinking things, I put some electrical tape on the back of the positive terminal, since it's closer to the metal chassis than it normally would be, to reduce the chances of something conductive bridging the gap between it and the negative chassis.

3 Answers 3


As long as everything is insulated well there is no reason you shouldn't do this.

One thing to consider would be in the case of a crash could the Positive be pushed into the chassis? Insulate accordingly.

  • 7
    As a general measure of safety, the positive terminal should always be covered with an insulated boot.
    – Paul
    Jul 31, 2016 at 18:19

Your battery needs to:

  1. Be securely and correctly connected to the battery wiring harness.
  2. Be mounted securely, to the car, in an upright position (don't spill acid everywhere).
  3. Not short against anything else.
  4. Be protected from the elements.

No matter what you do if you meet those criteria then you have no problem. As for #2 just remember that the battery is a heavy object usually filled with liquid (that can give off flammable / toxic vapors), use your imagination to predict the effects of physics accordingly (e.g. don't stick it to your roof with masking tape or try to balance it on your head while driving).

The battery in your photo appears to meet these criteria although I would, as you say, insulate the positive side to protect it from the chassis as well as from yourself. Plus the red boot visually indicates the positive side clearly, eliminating surprises for folks who may be expecting it to be the other way around.

  • Has anyone ever tried to balance the car battery on their head while driving? Jul 31, 2016 at 22:48
  • 1
    @immibis Yes, but it's an embarrassing story.
    – Jason C
    Aug 1, 2016 at 0:01

While there is nothing wrong with fitting this battery in your car, the fact that it sits backwards from what you would expect only means that it is not the battery that was made to fit your car. Car batteries are divided into "groups" based on size of the battery and location of the battery posts, and which side is positive.

  • Is there a good resource online to learn about the differences? For example, my car has a group 25 battery which is hard to find compared to others. I'm trying to find which groups are acceptable alternatives.
    – Snekse
    Jan 30, 2019 at 18:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .