Battery Cables and Terminals: Is Red Positive Or Negative?
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.
Updated: November 18, 2022.
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, negative battery terminal post is negative,
- jumper cables: positive cable (commonly with the alligator clamps) is the red one and is connected to the positive (red) battery terminal, and the negative cable is the black one and is connected to the negative (black) battery terminal,
- jump starters: positive cable (again, commonly with the alligator clamps) is the red one and is connected to the battery's positive (red) terminal, and the negative cable is connected to the battery's negative terminal (black).
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.
Battery and Jump Starter 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 remove 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.
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...
Battery and Jump Starter Cables Starter Frequently Asked Questions
Here are some of the most common Frequently Asked Questions about battery and jump starter cables.
Does red go on positive?
Yes, the red cable goes/is connected to the positive terminal of the battery, which is labeled with "+" and is also red.
Is red usually negative?
No, red cable or red battery terminal is never negative.
Do I connect black or red first?
When connecting the car battery to the car battery or the jump starter to the car battery, the red cable ALWAYS goes first.
When disconnecting, the order is another way around - disconnect the black cable first.
Why is the positive terminal red?
A negative battery terminal is connected to the car's chassis, which is common ground - touch it, and nothing will happen because you are also grounded via your feet.
On the other hand, red color is a synonym for danger. While 12V DC is not dangerous to humans, it is used to label cables and wires with a higher voltage than the common ground.
Is red positive or negative?
The red cable or red battery terminal is positive.
Is negative red or black?
The black cable or black battery terminal is negative.
Few Final Words
Battery jumper cables or battery jump starter can be of great help in certain situations. When used properly, they are a very safe alternative to the car's dead battery.
However, when not used properly, they can cause fire, damage, injuries, or worse. Always, if unsure, check the Owner's Guide or seek for professional help.
Also, when connecting cables, it is highly recommended to wear protective gloves and goggles.
