Which cable goes on first when installing a car battery?

“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 the 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.

What happens if you connect the negative terminal first?

If you connect the negative terminal first, the car’s entire frame becomes grounded together with the nuts and bolts of the frame. Once you connect the positive terminal and the spanner touches the frame or any grounded part of it, a short circuit may occur that could cause the battery to explode.

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Is it OK to touch car battery terminals?

In fact, under normal conditions, a 12-volt car battery will usually not even shock you. … That’s why you can touch both terminals of a car battery without receiving a shock, although you may feel a tingle if your hands are wet.

What happens if you take the positive terminal first?

If you remove the positive cable first, there is a chance your tool may come in contact with a metal surface on the vehicle and short out the battery, which can easily damage your electrical system and possibly cause the battery to explode.

Do you connect the positive or negative first when jumping a car?

Common Steps to Jump-Start a Car



First, clamp one end of the positive cable to the dead battery’s positive clamp. … Next, connect the negative cable to the negative terminal on the good battery. Finally, connect the other end of the negative cable to a ground on the vehicle with the dead battery.

Does it matter what order you connect jumper cables?

The safest order to attach the jumper cables is as follows: Attach one red jumper cable clamp to the positive terminal on the dead battery. Attach the other end of the same cable, the second red jumper cable clamp, to the positive terminal on the working (live) car battery.

What happens if you put positive on negative?

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.

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What happens if you put the positive cable on the negative battery post?

Connecting one battery positive terminal to the other’s negative will cause a great surge of electric current between them. … The heat produced is highly destructive as it will cause both the internal and external parts of the battery to melt.

Why does my battery spark when I connect it?

The battery cables can spark if the cables are installed in the improper order. When attaching the battery cables, place the positive cable on first and then the ground cable. … Also, the ground, or negative cable, should not be touching anything metal while the positive cable is hooked up.

What happens when you touch both battery terminals?

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 battery acid flying everywhere.

What happens if you connect the terminals of a battery?

If you connect a wire between the two terminals, the electrons will flow from the negative end to the positive end as fast as they can. This will quickly wear out the battery and can also be dangerous, particularly on larger batteries.

How do you change a battery without getting shocked?

Old toothbrush.

  1. Step 1: Safety First.
  2. Step 2: Find the Battery and Remove the Battery Holder.
  3. Step 3: Loosen and Remove the Battery Cables from the Battery Terminals.
  4. Step 4: Remove the Battery.
  5. Step 5: Install the New Battery.
Encyclopedia auto repair