It is annoying and distressing to have a car that won’t start. Usually, you’re left wondering what’s really wrong with the car, and the battery is usually the first to go wrong. Apart from looking up “how to tell if car battery is dead,” how can you determine if replacing the battery is necessary or if you can jump start it? How can you determine whether the battery is fully charged?
You can check if your battery is correctly charged using an inexpensive gadget and a quick multimeter test. Multi-meters range in price from $20 to several hundred dollars, and they’re quite beneficial for any necessary electrical work. Use a multimeter to find simple fixes for any issues that may arise from a dead battery. Here’s how to do it.
Checking the battery
It’s crucial to remember that while a multi-meter can be a fantastic tool for determining if your battery is completely charged and for testing a small amount of stress on the battery, it should never be used in place of a real load test, such as the one that AutoZone offers. Usually, the multi-meter test comes first, followed by the removal procedure, jumping the battery, and taking it to AutoZone for additional testing. Using this procedure, any automotive battery may be examined using a multimeter. There are caps over the top of the cells in batteries that are not “maintenance free,” sometimes one cap, sometimes two.
MANUAL FOR MULTIMETER USAGE
Battery testing with a multimer. A multimeter is essentially a tool used to test electrical circuits in a range of businesses. In addition to a variety of other applications, it may be used to measure continuity, voltage, resistance, and current. Although digital multimeters with a little screen that shows your results are more common nowadays, analog multimeters are still in use.
It requires one red lead and one black lead to be touched off or connected to a point. The black lead should be connected to the battery’s negative or ground contact, and the red lead should be connected to the battery’s positive terminal. To make sure the meter is set to DC voltage and that the test leads are inserted into the correct connection points for measuring voltage and continuity, you should consult the instructions that came with your multimeter.
Set your multimeter to the next number higher than the voltage you are checking if it has increments. Since 20 volts is the next greatest number to the anticipated 12+ volts in an automobile battery, for instance, if your digital multimeter includes settings for 2, 20, 200, and 2,000 volts, select that value.
After that, all you have to do is use the red lead to probe your circuit while connecting the black line to a ground source or contacting it to one. Take note of the voltage reading on the display.
Using a multitimer to test batteries
There are a few things to consider before learning how to test an automobile battery. The voltage measurement is the only test that a multimeter will perform on the battery. When it comes to maintaining that voltage under load, many defective batteries will show full voltage. This is how you can tell they are defective.
Secondly, a battery should only be tested after it has been inactive for at least one hour. “Resting voltage” is the term for this. A unit charged by your car’s electrical system, commonly known as a surface charge, may give you a misleading result if you test it right away after usage. You can begin working with your multimeter if you’re confident in your ability to utilize it.
WAYS TO USE A MULTIMETER TO TEST A CAR BATTERY
Testing a vehicle battery using a multimeter
1. GET YOUR MULTIMETER READY
If your voltmeter does not have incremental settings (2, 20, 200, 2,000), then just set it to DC volts. Otherwise, set your multimeter to voltage and make sure it is calibrated to 20 DC volts.
2. APPLY SPOT TO YOUR BATTERY TERMINALS
To test your battery, press each probe to the appropriate terminal, making sure to contact positive to positive and negative to negative. The positive terminal and probe will be red, and the negative terminal and probe will likely be black on your multimeter because the battery and multimeter are likely color-coded.
3. EXAMINE THE TEXT
When the car is off, check the original reading. The battery is instantly questionable if it starts off with less than 12 volts. Any battery has a starting voltage of at least 12.4 volts. Jump-starting a battery that is really low (8 volts or less) is usually not a smart idea since it puts a lot of strain on the alternator. Turn the car’s key to the “run” position and check the multimeter if the battery voltage is more than 12 volts. Noting down the reading is a wise decision. Next, contrast it with the voltage values shown below. Once the car is turned on, check to see whether there is a significant voltage decrease.
Outside temperature has an impact on the battery’s voltage. A completely charged battery should measure between 12.5 and -12.6 volts at 80 degrees. In precise terms, a completely charged battery should read 12.66 volts or above, however readings as low as 12.6 volts at 80 degrees, 12.588 degrees at 30 degrees, and 12.516 volts at 0 degrees are all acceptable. Anything less than 12 volts signifies that the battery has been completely depleted, while a 75% charged battery will measure closer to 12.45 volts.
Try charging the batteries to its maximum capacity if the readout is between 12.3 and 12.5 volts and you can charge the battery. This process shouldn’t take too long. Check the voltage and switch on the heater blower motor and headlights after that. A few tenths of a voltage loss is to be expected, but nothing too significant. When someone tries to crank the car, test the battery with a multimeter if the car is still not starting, as in, you are receiving a click or buzz when trying to start it.
Watch the reading as this takes place. When a significant load, such as a starter, is applied to most excellent batteries, they will typically dip one to 1.5 volts and then swiftly return to full charge. An indication that the battery could be defective is if you see it dip from 12.5 volts to, say, 8 or 9 volts or less.