Battery Equivalents and Replacements

Battery Cables and Terminals: Is Red or Black Positive?

When connecting batteries, jump starters, jumper cables, and similar to the car's or similar batteries, it is very important to know which cable and terminal post are positive and which ones are negative.

Also, it is very important to know which one to connect or disconnect first.

Not knowing such information can be dangerous since car batteries and jump starters are able to provide huge currents, even when not fully charged.

Published: August 2, 2022.

 optima battery

To keep things as simple as possible, remember that the red is positive and that the black is negative:

- battery terminals: positive terminal post is the red one,

- jumper cables: positive cable (commonly with the alligator clamps) is the red one,

- jump starters: positive cable (again, commonly with the alligator clamps) is the red one.

Knowing this is very important - when connecting the battery to the battery, or jump starter to the battery, if they are short-circuited, huge currents (thousands of currents) will melt the insulation within seconds and most probably start a fire - that is how these cables can get hot if something is connected in the wrong way.

Cables Connecting Order

When connecting the battery to the battery or jump starter to the battery, remember that the car is common ground - it has chassis connected to the negative battery terminal post (also known as "minus") via black cable.

Thus, when connecting the battery to the battery or jump starter to the battery, always connect the positive (red) cable first and only then the negative (black) cable.

When disconnecting the battery from the battery or jump starter from the battery, always disconnect the negative (black) cable first and only then the positive (red) cable.

This way, if the cable clamps are accidentally dropped on the exposed metal of the chassis, there will be no short circuit.

jumper cables

Note: when using jumper cables or jump starter, if You are unsure about the exact procedure, it is good practice to check the instructions/manual - better safe than sorry...

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