How to Tell If A Car Battery Is Negative Or Positive?

Jump starting a dead battery can be a crucial skill for car owners. This requires that you are able to distinguish between the negative and positive terminals of a car's battery. If you aren’t used to working with the car battery, the two can be confusing.

What can you do to tell the difference between the negative and positive terminals on a car battery's lithium-ion? Red is the most common color for the positive battery terminal. It usually has a (+) sign on its cover. Negative battery terminals are the opposite. You might see a cover with a black minus sign. The color-coded wires leading to the terminal can also be used as a clue.

This guide will show you the difference between positive and negative terminals of your car's battery. Also, we will show you how to connect jumper cable when your battery has died. 

What's the positive terminal on a car battery?

The red color of the positive terminal cover is common for batteries. But, this isn't the only method used by car manufacturers. If the terminals aren’t color-coded, you can also look at the cover to see if there’s a plus (+) sign on it.

You might be wondering what to do if you lose the cover. It is going to take you a different route to find the terminals. Some vehicles will have wires that lead to the terminal colored red. This helps you distinguish between them. 

To be certain that the battery terminals are positive or negative, we recommend using a multimeter..

What's the Negative Terminal in a Car Battery Battery?

Sometimes the terminal that is negative of the battery may be darkened. It is possible to get confused if one of the terminals is red and the other are both black.

If so, look at the battery cover and make sure there's a minus sign (-). You have located the negative terminal on the battery if this is the case. 

Black should be used for the wiring insulation, while red is required for the positive. The negative side of the wiring will be connected to your vehicle's metal chassis. 

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The Right Method to Use Jumper Cables

While it’s easy to jump start a vehicle with a set of cables, there are some precautions that must be taken. You could inflict injury or damage on your vehicle if you accidentally mix the jumper cables connectors. For this reason, it’s wise to understand the steps before proceeding. Also, we recommend safety glasses and protective gloves.

Here are some basic steps to follow, but you can get more detail by reading through your car’s service manual.

1. Connect the positive jumper cables to your dead battery's positive terminal.
2. The other end of the positive jumper cables should be attached to the positive terminals on the battery.
3. A negative jumper cable should be attached to the terminal of your positive battery.
4. Attach the other end to the negative jumper cable at a location near the battery. Look for heavy-duty parts made of bare metal. This can be found on the engine, or attached to the chassis. These all create a solid ground connection. You don’t want to place your negative jumper cable end to the negative terminal on the dead battery. Sparks can ignite fumes from the dead battery if you do this. 
5. Before you move forward, double-check every connection. It’s important that everything is secure.
6. Make sure the battery is charged before you start the car.
7. Turn the engine until it reaches 1,500 to 2,00 RPMs. Continue to rev the engine for several minutes. 
8. Start the car if it has a dead battery. You may need to try several times before it starts. 
9. When the engine has started up, unplug the ground connector that is connected to the negative jumping cable.
10. If you have a good battery, both negative and positive cables can be removed from your vehicle.
11. Last, disconnect the positive cable at the end of the car that has a dead battery. 

It’s important that you don’t turn off your car engine for at least thirty minutes. Only the good battery provided a superficial charge for the dead battery. You will find yourself in the exact same position if you turn off your car. Let the alternator fully charge your battery. It’s best if you can take the vehicle for a drive down the highway to get the alternator working faster. 

RELATED: Which Size Jumper Cables Should I Use? (2 vs 4 vs 6 Gauge)

What Happens If Battery Cables Get Hooked Backwards?

With the jumper cable polarity altered, there’s a big difference in the electrical current that’s flowing to each. Because of this, it’s possible to melt the cables or cause a car fire because of the difference. For this reason alone, it’s very important that you always hook up the battery cables the right way.

The good news is that automakers realized this was a common problem for people that don’t understand car batteries. Many manufacturers have a main fuse installed that can blow out before any problems arise. You can blow your main fuse by connecting the terminals incorrectly. If that’s the case, you can simply reverse the cables and replace the main fuse to get back on the road.

READ MORE: Battery Terminal Corrosion Causes (How to Fix & Prevent It)