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How to Check Battery Amps with a Multimeter – Cranking Amps and Amp Hours
Batteries are one of the essential elements of our cars. Any harm incurred by the battery can affect your vehicle as well. If your car headlights stop working or you are unable to turn on your car engine, there is a good chance that your battery has suffered some form of damage. The best way to ensure good battery life is to check it from time to time. The Multimeter is one of the best tools to test car battery amps. Read on to know more about how you can employ the Multimeter to check battery amp-hours, automotive battery, etc.
How to Check Car Battery Amps with a Multimeter?
A Multimeter is an effective tool for testing your car batteries. Once you have perfected the measuring process, it will be easy for you to test the car batteries.
If you want to perfect your reading, you should start by practicing different types of cells. For instance, you can practice with batteries from remotes, video games, torches, lamps, etc.
1.Check your Multimeter by setting down its functions to ohms. When you connect the test leads, the readings should be zero, and they should be one when the connection is severed. In case the battery does not follow the pattern mentioned above, then there is something wrong with the same.
2.The multimeters available in the market are of two types – analog and digital multimeters. The former displays readings with the help of a micrometre and a moving pointer. Meanwhile, the latter shows the reading with the help of a numerical display.
3.You will have to set the Multimeter at 20v Volt. The 20V range implied that the ranging meter will measure between 0V and 20V.
4.Turn off the ignition and car radio.
5.Next, you will have to locate the battery of your car. The car battery is located in the engine room. You will have to open and search for the battery close to the car engine. You will have to connect the Multimeter to the batteries of your car. The Multimeter's red probe shall be connected to the positive terminal. Meanwhile, the black probe must be connected to the negative terminal.
6.You can turn on the Multimeter and set the correct voltage range to measure the battery voltage. Car batteries offer 12.6V Direct Current via six cells, each of which produces 2.1V.
If your car battery reads 12.6 V, it means that it is fully charged. Meanwhile, 12.4 V means the battery is 75% charged. 12.2 V implies 50% charged and 12 V implies that it is 25% charged and should be charged as soon as possible.
If the reading shows 11.9 V and below, it is indicative of the fact that the battery is completely discharged.
How to Test Automotive Battery and Cranking Amps with a Multimeter?
Owing to how fast multimeter tests are and how reliable the results are, multimeter tests are done worldwide at home and by car technicians. There are tons of multimeters available on the internet, and you can easily buy one to take care of all your house batteries without the help of a car mechanic.
Here are the steps you can follow to effectively check the Cold Cranking Amps or CCA of a car battery.
1.Connect the Multimeter to the battery terminals and kickstart the car's ignition. You will need an extra pair of hands for the task as one will have to control the ignitions, and the other person will have to monitor the fluctuations while the engine is still up and running.
2.The ideal situation is the reading on the Multimeter goes down to 10V and then comes up to show a reading of around 12 V. If the reading stays the same after the first value drop, it indicates good condition.
3.If the initial reading on the Multimeter is around 5 V and not less, it means that your car's battery won't last long. If the reading is way below 5 V, it is time for you to replace the cells.
How to Check Battery Amp Hours with a Multimeter?
Technicians use the term mAh or Milliamp-hours to find out about the operating lifetime of a car battery. Here are the steps to check the mAh with the help of a Multimeter:
1.Set the control knob of the tool to the battery check position. In case the meter's internal battery has been depleted entirely, you can replace it,
2.Put the battery in a holder. You will have to use a snap-on battery clop and wire leads for 9-volt batteries.
3.Place the alligator clips on the tips of the meter's probe.
4.Pick a resistor that is perfect for the battery voltage and a typical drain current. The following table can help:
D battery, 200 ma drain current.
C battery, 100 ma
AA battery, 50 ma
AAA battery, 10 ma
9-volt, 15 ma
You can divide the battery's voltage by the current drain in amperes to get the value of resistance.
5.Reset the stopwatch.
6.Connect one of the resistors leads with the positive terminal of the car battery
7.Change the position of the control knob to read DC or direct current in the 2200 milliamp range.
8.Clip the positive probe to the resistor lead, which is unconnected. Next, clip the negative probe to the negative terminal of the battery. You will receive a positive current reading on the meter.
9.Start the Stopwatch
10.Make sure to check the reading of the current after every hour. Stop the stopwatch when the current has reached about 70% of the original reading.
11.You will be able to calculate the milliamp-hour of the battery by multiplying the current reading on the meter and the hours recorded on the stopwatch.