QA

Why Shouldn’t You Connect The Negative Terminal

Why can’t you connect the black jumper cable to the dead battery’s negative (–) terminal? This is so you can avoid sparks from occurring near the battery where flammable hydrogen gas may be present, resulting in a possible explosion.

What happens if you connect the negative terminal first?

It is only a safety issue. If you first connect the negative cable, then when you connect the positive cable there is a chance the wrench will complete a circuit between the battery and the chassis of the car. This will at a minimum generate a spark, but that spark could eject molten metal toward you causing injury.

Can you connect negative to negative when jumping a car?

Caution: Don’t attach the negative cable to the negative terminal of the weak battery when jumping a car battery! This common mistake could ignite hydrogen gas directly over the battery. Battery explosions can cause serious injury.

Can you touch the negative battery terminal?

In fact, under normal conditions, a 12-volt car battery will usually not even shock you. The math can get a little complicated, but the main reason that you can safely touch the positive and negative terminals of a typical car battery, and walk away unscathed, has to do with the voltage of the battery.

Do you connect negative battery?

When disconnecting the cables from the old battery, disconnect the negative first, then the positive. Connect the new battery in the reverse order, positive then negative.” When you are replacing your car battery, It isn’t always easy to remember the order in which to disconnect and reconnect the terminals.

Why do you connect negative to ground?

A “ground” is a metallic/unpainted part of the engine or frame/chassis. The reason for connecting the negative cable to ground rather than to the negative terminal of the dead battery is to minimize the chances of a spark near the battery, where there may be potentially explosive gasses.

What can happen if you attach both negative clamps to both battery terminals?

Also, you CANNOT let the clamps touch each other once they are attached to the donor battery. Any contact between the clamps will produce a spark which will burn your hands, or worse⁠—ignite flammable liquids in your engine.

What happens if you connect negative to positive?

Connecting the positive terminal of each battery to the negative terminal of the other battery will result in a huge surge of electrical current between the two batteries. The heat can melt internal and external battery parts, while the pressure from the hydrogen gas can crack the battery casing.

What happens if a wrench touched both battery terminals?

Tom: The danger from car batteries is not so much electrocution as it is explosion. If you touch both terminals with a metal wrench, for instance, you can create a spark that can ignite hydrogen gas in the battery. That can send pieces of battery and acid flying.

Does Black connect first or red?

Connect the positive terminal first. Attach the red (positive) terminal to the positive battery post. Tighten the terminal with a wrench. Repeat the process with the black (negative) terminal.

Does jump starting a car damage the computer?

Like most electronics, a power surge can cause damage to the electronic systems of a modern car. A seemingly well-meaning jumpstart can cause said power surge and impact the effectiveness of onboard computers, safety systems, damage the engine and be the result of expensive repairs.

Why do you remove the negative terminal first?

The reason they say to remove the negative first is because it is safer for you. The negative cable in all modern cars is attached to the chassis of the car. SO when you put your wrench on the negative post to loosen it, and the wrench hits the chassis, nothing happens.

Can jumpstarting a car damage yours?

Most of the time, giving someone else’s vehicle a jump start won’t damage your car. They’d take charge of your battery but you could recharge that by simply using your car. If the jumpstart is successful, there is really no serious damage that the donor car gets.

What happens if you lick a car battery?

You can lick a big honking D battery until your tongue is dry. But if you lick a rectangular 9-volt battery, touching both the positive and negative terminals, you will receive a small electric shock.

Is it safe to touch a battery?

electricity needs to flow in loop, a circuit. Touching only ONE terminal w/o touching (something that’s connected to the) other terminal is generally safe. Normal skin resistance is too high to be overcome by regular battery voltages, so nothing will happen anyhow.

How do I prevent my car battery from getting shocked?

Using Styrofoam as a tool tray will help prevent any accidental electrical charges that can be generated if your metal tools touch your car’s metal surfaces while you work on the battery. Your battery is cleaned, you’ve searched for cracks and your tools are laid out.

Can I just disconnect negative terminal?

Q: Can you just disconnect the negative terminal? You can disconnect the battery’s negative cable. All you are required to do is to locate the negative polarity of the battery and disconnect the terminal. Avoid the negative terminal to make contact with the positive one.

Can you use the negative battery terminal as a ground?

The negative terminal is never called ground. It is connected to the ground in order to maintain the positive terminal potential at the rated voltage.

Can a battery drain with the negative cable disconnected?

Be safe: always disconnect negative first. Disconnected either terminal will prevent drain, as stated already. A battery tender is another safe way to maintain the battery.