# Can you use a multimeter to test battery capacity?

## Can you use a multimeter to test battery capacity?

Milliamp-hours, or mAh, are the units technicians use to measure a battery’s useful operating lifetime, or how long the battery will last when it powers a normal electrical load. You can measure a battery’s mAh rating using a multimeter, a resistor to act as a load and a stopwatch to measure elapsed time.

### How do you measure the remaining capacity of a battery?

Battery capacity is measured in milliamps × hours (mAH). For example, if a battery has 250 mAH capacity and provides 2 mA average current to a load, in theory, the battery will last 125 hours.

How do you set a multimeter to mAh?

Connect the negative terminal of the powered device to the positive terminal of the battery using a piece of electrical wire stripped at both ends. Write down the current reading from the multimeter screen and start the stopwatch. If the reading is in amps, multiply by 1000 to convert to milliamps.

How do I check the capacity of my 12 volt battery?

To determine the AH rating of a 12-volt battery, use a multi-meter. Connect a basic resistor across the battery’s terminals, then monitor the discharge over time until the voltage decreases to 12 volts. You can then use a measurement of the battery’s current to calculate the AH rating.

## How is battery discharge rate calculated?

In this case, the discharge rate is given by the battery capacity (in Ah) divided by the number of hours it takes to charge/discharge the battery. For example, a battery capacity of 500 Ah that is theoretically discharged to its cut-off voltage in 20 hours will have a discharge rate of 500 Ah/20 h = 25 A.

### How do you test a lithium ion battery with a multimeter?

Turn on your multimeter and set it to measure voltage. Place the sensors on the end of the two wires from the meter onto the positive and negative terminals of your Li-Ion battery or battery pack.

What should my battery range be on my multimeter?

Most of the manual ranging meters have a 20V range, which is what you need to test a car battery. The 20V range means it will measure between 0V and 20V. Tip: if you are a beginner looking how to use a multimeter to test a car battery to ascertain its voltage, consider getting one that has a dedicated battery tester range on it.

How do you stop the timer on a multimeter?

Plug the red probe of the multimeter into its positive port. Connect the red probe of the multimeter to the negative terminal of the battery. Stop the timer when the device being power by the battery shuts off. The battery is now drained.

## Can a hydrometer be used to test a battery?

You can use a hydrometer-style battery tester to test the individual cells by testing the specific gravity of the acid in each cell, but even once you find a bad cell, you’re arriving at the same place you would by simply using your multimeter to do some simple voltage tests. Testing Batteries with a Multimeter

### How do you measure the capacity of a battery?

Learn to determine the capacity of a battery in milliamp-hours (mAh) to know how much charge it holds when full. Turn on the digital multimeter and switch its measurement dial to the direct current (DC) measurement setting, since all batteries produce DC current. Plug the red probe of the multimeter into its positive port.