What is the correct sequence for disconnecting battery terminals?

“Positive first, then negative. 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.”

Does it matter which battery terminal I disconnect first?

Disconnect the Battery Cables

Make sure you disconnect the negative terminal first. Lay the disconnected negative cable carefully to one side, making sure it's well away from the battery terminal. Disconnect the cable from the positive battery terminal in the same way, then lay it to one side.

Do I disconnect the red or black first?

Always disconnect battery cables exactly in this order; disconnect the BLACK negative cable first, and then disconnect the RED positive cable. Always connect battery cables exactly in this order; connect RED positive cable first, then connect BLACK negative ground cable.

How do you disconnect a car battery?

Why do you remove the negative terminal first?

Negative first

It's important to disconnect the negative side of the battery first, otherwise you can cause an electrical short if the positive is removed first.

Proper Order For Connecting And Disconnecting Car Battery Terminals

Which terminal should be connected first?

“Positive first, then negative. 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.”

Why do you connect positive terminal first?

Connect positive first, negative having less potential won't arc. The higher the voltage, the greater the chance of arcing and fusion. On a car if negative first and you are touching any metal part of car, when attaching positive there is possibility of arcing through you. Your body becomes part of the circuit.

Why do you connect red first?

Connecting the red terminal to the dead battery first would minimize damage if the other red clamp were accidentally dropped so as to contact the frame of that vehicle.

How do I keep my car battery from dying when not in use in winter?

Can you just disconnect the positive terminal?

Premium Member. You will be fine. Disconnecting either cable works. The reason they say to disconnect the negative and not the positive is because while taking the positive connection off with a wrench if you happen to touch anything with the wrench while it's on the positive terminal it can arc and be dangerous.

What happens if you disconnect the battery while the car is still running?

Removing the battery from the circuit allows those spikes and transients to travel around, endangering every semiconductor circuit in your car. The ECU, the speed sensitive steering, the memory seat adjustments, the cruise control, and even the car's stereo.

Do I disconnect the positive or negative to check the alternator?

You can check the alternator by simply starting your car and then disconnecting the negative battery cable. Be careful doing this, though, because there are a lot of moving parts in your engine compartment that could cause injury.

Is it OK to just disconnect the negative terminal?

Disconnect battery negative cable

It is a good practice to always disconnect your negative battery terminal first, to minimize the risk of sparks that can lead to car electronics damage and battery explosion. Once you have located the negative terminal, use the wrench to free the nut that tightens the terminal.

Why is my battery sparking when I hook it up?

Sparking from a battery is perfectly normal. As long as the sparks aren't massive, they don't come with smoke, and it only sparks when connections are made, there's nothing to worry about.

Does it matter what order you connect jumper cables?

Don't attach the negative (black) clamp to the negative terminal of the dead battery. It is important to connect the cables in that order, and it is safest to connect the negative (black) clamp as far from the battery as possible, in order to reduce the risk of sparking that could cause a fire or explosion.

Do you connect ground first?

Correct, when components are designed to be hot-plugged or hot-swapped, they need to make contact with ground first, and disconnect ground last. Otherwise the stray voltages on isolated devices could force high currents to flow through data pins, damaging their transistors.

What happens if you disconnect the positive terminal while car is running?

If your alternator is malfunctioning by over-charging your battery, disconnecting it may allow the alternator to provide an even higher voltage to the car electronics, and potentially damage those sensitive components.

When jumping a car which cable goes on first?

Attach the red jumper cables first. Start by clamping one red cable to the positive side of the battery that won't start. Then attach the other red clamp to the positive side of the working battery. Next, clamp one black cable to the negative side of the working battery.

Should battery Disconnect be on positive or negative?

The negative cable connects to the body ground already—so there's no additional danger if it rubs. It's the same principle as why you should always disconnect the battery's negative side first before performing electrical service.

Should I disconnect battery if car parked long term?

If you don't have access to an outlet - say, in a long-term airport parking lot - your second option is to disconnect the battery. That'll preserve the battery's charge, so when you reconnect it, the truck should start right up.