Wet cell batteries naturally discharge a small amount each day whether you use the battery or not. Typically, the alternator in your car will recharge the battery in the natural course of starting the engine. However, if the fluid level in the battery cells is low or the battery has been sitting for a long period of time, you may need to use a battery charger to replenish the charge.
Put on the safety glasses and rubber gloves.
Use the wrench to loosen the battery cable connection to the terminals. Remove the cables from the terminals.
Clean the battery terminals and the cable ends with the brush and the terminal cleaner. Dry with a rag. This will ensure that you get a good connection when you reconnect the battery to the cables.
Attach the red cable from the battery charger to the positive terminal on the battery. You will see a plus sign next to the positive terminal. Attach the black cable from the battery charger to car frame or engine block. Make sure that you do not catch wires or hoses in the clip or that you clip sheet metal, or you will damage your car.
Set the voltage switch to either 6 or 12 volts, if the battery charger comes with a voltage switch. Most car batteries require 12 volts. Set the rate switch to 2, 6, 12 or 30 amps, if the battery charger comes with a rate switch. The lower the rate, the slower the charge. If you have a battery in storage, setting a 2 rate would provide a trickle charge. Set the timer if you want. The timer will turn off the battery charger after a set period of time.
Plug the charger into a grounded outlet. Leave the charger plugged in until the battery is charged. How long it will take to recharge depends on how low the charge was in the battery, the rate setting and the size of the battery. It may take an hour to several hours to fully charge the battery.
Unplug the battery charger when done. Remove the clips connecting the battery charger to the battery. Replace the battery cables. Tighten with the wrench but do not overtighten or you can break the terminals.
