Battery Test
The car battery is the base where the electrical power for your car originates.
This battery stores electricity to start the engine and operate electrical accessories
in the electrical system throughout your car when the
engine is not running. Car batteries
are equipped with a positive and negative terminal from which the
battery cables are attached. Battery
cables route power from the battery to the power distribution center. Because most
batteries are filled with acid use caution when working or testing a battery by
wearing protective eyewear, gloves and clothing.
Never connect anything across battery terminals to create a short. A car battery
is a high amperage-low voltage unit that can deliver a high amount of amperage very
quickly and can cause burns and possibly fire. Never disconnect a battery when the
engine is running, this can cause
electrical system and
computer damage. Most car batteries must have a "rest" or "down" test to allow the
plates inside the battery time to cool. If a battery is subject to constant charge
and discharge it will fail prematurely. Also, a battery cannot be discharged completely
and then recharged it more than a few of times before the battery fails unless it
is a deep cycle battery. A car battery is hazardous material so you most dispose
your old battery at your local car parts store.
Testing a Battery
Car Battery Checking
First check the battery surface voltage by removing the positive terminal cover. Connect a voltmeter positive lead (red) to the positive battery terminal. Then connect the negative (black) meter lead to the negative terminal of the battery. Without the engine running allow the car to sit overnight. Then observe the voltage it should be between 12.4 and 12.7 volts. Alternator Identification
Alternator An alternator is driven by a serpentine belt connected to the engine. While the engine is running it rotates the alternator to supply electrical voltage and amperage to recharge the battery and to the electrical system. The alternator is held in place with mounting bolts connected the engine. There are electrical wires connected to the rear of the alternator to supply voltage to the voltage junction block. If a alternator is not charging properly the battery will slowly drain and eventually cause all electrical systems to stop the car engine from running. If further technical assistance is needed, our certified car repair technicians are ready to answer your car questions.
Common Problems
Car Battery Checking
First check the battery surface voltage by removing the positive terminal cover. Connect a voltmeter positive lead (red) to the positive battery terminal. Then connect the negative (black) meter lead to the negative terminal of the battery. Without the engine running allow the car to sit overnight. Then observe the voltage it should be between 12.4 and 12.7 volts. Alternator Identification
Alternator An alternator is driven by a serpentine belt connected to the engine. While the engine is running it rotates the alternator to supply electrical voltage and amperage to recharge the battery and to the electrical system. The alternator is held in place with mounting bolts connected the engine. There are electrical wires connected to the rear of the alternator to supply voltage to the voltage junction block. If a alternator is not charging properly the battery will slowly drain and eventually cause all electrical systems to stop the car engine from running. If further technical assistance is needed, our certified car repair technicians are ready to answer your car questions.
Common Problems
- The alternator fails producing electrical power causing the car to stall
- Battery fails due to age or internal defect
- Battery cables come loose causing the electrical system to fail