How to Disconnect a Car Battery

An automotive battery is a rechargeable battery that supplies electric energy to an automobile. Traditionally, this is called an SLI, for starting, lighting, ignition, and its main purpose is to start the engine. Once the engine is running, power for the car is supplied by the alternator. Typically, starting discharges less than three per cent of the battery capacity. SLI batteries are designed to release a high burst of current, measured in amperes, and then be quickly recharged. They are not designed for deep discharge, and a full discharge can reduce the battery's lifespan.

 Steps

1、Take the necessary precautions before you try to disconnect your battery. Besides holding a potentially lethal electrical charge, batteries contain corrosive agents that can produce a flammable gas. Before you remove your car's battery, take these safety steps。

*Turn off the ignition.

*Wear safety goggles and gloves to protect your eyes and hands.

2、 Find the negative terminal on the top of your car's battery. 

It usually has a black cover. The battery itself may have a minus sign near the connector post. The positive terminal usually has a red cap or a plus sign on the battery near its connection post. 

 3、Determine what size socket you need to loosen the nut on the negative terminal. Always work on the negative terminal before the positive when you disconnect your battery. 

*Grab a socket from your socket kit and hold it near, but not against, the nut on the negative terminal of your battery. Ascertain visually the socket size you'll need to loosen the nut. 

* Put the appropriately sized socket on your wrench. You might have to attach a wrench extender to reach the nut.

* Put the wrench on the nut on the negative terminal and turn counterclockwise (remember: righty tighty, lefty loosey). It will take only a few turns to loosen it.

*Pull the negative connector from the battery after you've loosened the nut. Push it aside so it is unable to make contact with the battery while you're doing your work.

* If the cable is seized to the battery post, a special battery cable removal tool may be needed to remove the negative connector. Ask your local auto parts store or mechanic.

4、 Follow the same procedure to disconnect the positive terminal. 

 After removing it from the terminal, don't let the positive connector touch any metal part of the car. There is residual current in the system that, if it were to touch a metal surface, could disrupt or damage the circuits in the vehicle. 

5、Continue with your work. 

 With the battery cables disconnected, you can safely perform repairs on electrical components of the vehicle. If you just need to put in a new car battery, it can be done in a few simple steps.

* After the battery is disconnected, unscrew the brackets that hold it in its tray.

*Lift the battery straight up, out of its tray. Keep in mind that car batteries can weigh 40 lbs. so ask for help if you need it.

* Using an old toothbrush, brush the tray and battery cables with a diluted baking-soda mixture and allow them to dry before putting in your new car battery.

*Place the new battery on the tray and tighten the clamps. 

*Connect the cable for the positive terminal first, then the negative. Remember to securely tighten the nuts on each.

*Close the hood and start the car. 

*Dispose of the old battery properly. The auto-parts store you bought your new battery from probably will take the old one as part of its service arrangement. If not, take it to a recycling center or automotive garage. Most accept old batteries for a nominal fee.