How to Use a Battery Charger for a Car

You don't have to buy a new car battery every time yours dies.

It's no fun when you attempt to turn your car on in the morning only to hear the clicking noise of a dead battery. But you don't have to buy a new battery every time you hear that sound. Most of the time, batteries can be charged from another car; occasionally, they will need to charge for a set time with battery charger.

Things You'll Need

• Battery charger
• Car battery
• Outlet

Instructions

1. Read the instructions that came with the battery charger to make sure you know how your specific battery charger works.

2. Connect the battery charger to the battery. If the battery is connected to the car, attach the positive (usually red) charging cable to the positive post (usually marked with a plus sign). Then attach the negative (usually black) charging cable to the engine block. Do not connect the negative cable to the negative post while the battery is in the car. If the battery is not connected to the car, attach the positive charging cable to the positive post. Then attach the negative charging cable to the negative post, usually marked with a minus sign.

3. 

   Turn the "Volt/Amp Selector" to the appropriate type of battery and amps, and make sure that the correct "Volt" switch is selected for the size of battery.

4. Plug the battery charger into an appropriate outlet. If the cord has a ground, plug it into a grounded outlet. Do not alter the cord in any way.

5. 

   Turn the "Charge Time" to set how long you want to charge the battery. Use the ammeter to measure battery-charging rate. Use the battery test monitor to see if the battery is in working condition.

6. Turn the battery charger off. Unplug the battery charger from the outlet. Turn the "Selector" and the "Charge Time" to "Off."

7. Remove the negative battery charging cable first, then remove the positive charging cable.

Tips & Warnings

• Always set the negative charging cable away from the battery.

• Batteries may explode. Always wear eye protection.

Resources

• Battery Chargers: Instructions for Your Safety