Car batteries can be discharged during vehicle operation, making it impossible to start the car engine. You can avoid such problems with the help of timely service and control of the battery charge, which allows you to recharge the battery or change it to a new one. It is not difficult to measure the battery capacity with a multimeter, so every car owner can handle such a simple diagnosis.
Content
- Description of the multimeter
- Types of devices
- Meter device
- Battery charge control
- Determination of battery capacity
- Check discharge method
Description of the multimeter
For measuring the capacity of various types of batteries used multimeters - special devices that combine the functions of an ohmmeter, voltmeter and ammeter. The universal device is distinguished by its simplicity of operation, allowing the most accurate determination of the capacity indicators of the battery.
Using such a device, you can check the performance of consumer electronics and the presence of voltage in the outlet, find a wire break or measure the battery capacity. The device determines the continuity of the supply of current in the network, is capable of working with constant and alternating voltage. Select models provide circuit resistance data to help identify short circuits and other power problems.
Types of devices
Today on sale you can find both universal multimeters and special devices that are designed to perform certain measurements. Depending on the type and design it is customary to highlight devices:
- analog;
- digital.
Analog devices are simple in design, so it is not difficult to independently measure the battery capacity with a multimeter. At the same time, such devices ensure the accuracy of measurements, allowing you to visually display the current strength and voltage in the network. Analog models have a small arrow, which, depending on the voltage indicator, will deviate along the corresponding scale, clearly displaying the voltage and current strength.
Digital models have advanced functionality, and their use is not difficult. The simplest devices are recommended primarily for ordinary car owners who would like to independently check the battery capacity with a multimeter without the appropriate knowledge in radio electronics.
Meter device
Most multimeters are of a standard design, which greatly simplifies their use. The device itself is equipped with a digital display, which displays the current measurement values and other service information. The fixtures have corresponding buttons or function switches that expand their capabilities.
On the case of the multimeter, you can see the holes for connecting the probes. The probes used have a metal tip, plastic or wooden handles, which are made of non-conductive material. The red probe is used to measure positive polarity, and the black one is used for negative polarity.
Battery charge control
It is not difficult to check the battery capacity with a multimeter. Due to their versatility, such devices can be used to work with car batteries, batteries from cell phones, smartphones, tablets and laptops.
The principle of using meters in all cases will be the same. Having learned how to measure the battery charge, it will be possible in the future to easily use such a device in work and in everyday life. The charge measurement algorithm is as follows:
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It is necessary to turn on the multimeter, for which the mode switching lever is set to the "Constant current" position. - The probes from the multimeter are connected to the plus and minus of the battery. The polarity must be observed using the red plus probe. A wire with a black handle is connected to the negative output.
- The device displays the received data on battery capacity and current power.
The results obtained should correspond to the capacity and charge of the specific battery. If a battery is being measured, a fully charged battery should have an amperage of 12.6 V.
For partially discharged batteries, the capacity measurement indicator is 12.2 V. If the readings of the device fall to the 11 V mark, the battery must be dismantled from the car and recharged at home.
Determination of battery capacity
With a multimeter, you can measure not only the current strength, but also the battery capacity. To do this, set the switch of the device to the appropriate position, and then connect the red and black probes to minus and plus. Having correctly calculated the capacity indicators, it will be possible to determine the health of the battery, and, if necessary, replace the electrolyte or clean the sealed cans near the battery.
For maximum measurement accuracy the battery must be connected to the loadwhich draws approximately half of the battery current. If the battery capacity indicator should be 7 Ampere-hours, then the optimal load is 3.5 watts. The easiest way to get such a load is using a bulb from a car headlight, which is connected using ordinary wires to the plus and minus of the battery.
After connecting the load in the form of a light bulb, you should wait a few minutes and only then start measuring. The capacity of the battery will vary depending on its type and specific model, so you must first study the instructions, where this data will be indicated. When performing self-measurements with a multimeter, you can determine the serviceability battery, and in case of a significant deviation from the norm, restore it or replace it the battery being used.
Check discharge method
Using the test discharge measurement method, you can determine the health of the battery and its ability to retain a charge. For such a check, it is necessary to fully charge the battery by loading it according to the calculated value in the battery passport. After that, a multimeter or ammeter is included in the circuit, and the current strength and capacity indicators are displayed on the device screen.
Several measurements are taken to determine the level of discharge of the battery and its ability to maintain its charge. If there are minimal discrepancies in the decrease in current strength in comparison with the passport data, then such a battery is suitable for use. In this case, you will need to fully charge the battery, which will stably hold a charge, solving problems with starting the engine even in severe frost.
Using an analog or digital multimeter, you can measure the voltage, preventing problems with the operation of the vehicle. It is not difficult to measure the battery capacity with a multimeter, so everyone can get data on the voltage and capacity of the battery and batteries in various electronic gadgets.
