The first thing EV owners must learn about volt meters is that theyíre the EV equivalent of a gas gauge. While there are multiple types of voltmeters available today, the basic volts-only meters and high-tech volt meters today provide the same function, and that is to determine the electrical potential difference between two points in an electric circuit.
Itís common encyclopedia knowledge, too, that these voltmeters are the instrument that help measure voltage of both direct and alternating electric currents on a scale usually graduated in volts, millivolts (0.001 volt), or kilovolts (1,000 volts). This scaling will be represented in the many types of voltmeters available for EVs today. Some of these major voltmeter types include electrostatic voltmeters and potentiometers.
A potentiometer operates by making a strong comparison of the strong voltage to be measured within the range of known voltage and are commonly used to measure low voltages. On the other hand, the electrostatic voltmeter will use electrostatic forces that allow to measure direct voltage rather than just relying on the currentís consequence.
You should know that there are digital voltmeters that give numerical displays in their readings. The output provided here can easily be transmitted over distance and may even be able to activate printers or computers in other units. This implies that the data rendered from digital voltmeters are more accurate and more transferrable compared to their analogue counterparts.
If a basic analog voltmeter will consist of a sensitive galvanometer (current meter) during a series of high resistance, this implies that the internal resistance of a voltmeter should also be high, too, as a direct consequence. On the other hand, a digital voltmeter will be able to do the same thing, but can offer a more accurate and larger voltage values, extending to several significant figures beyond the normal voltmeter. In fact, you can expect lab volt meters to reach as high as about 1000 to 3000 volts (V). This may not be applicable directly to todayís EVs, but the future may beg to differ.
Because of a voltmeterís sensitivity and input resistance, it can be increased if the needed current required to move the meter pointer will be supplied by an amplifier or a power supply during a circuit test. In the case with analog voltmeters, this is best represented by a moving coil galvanometer through the insertion of resistors. Some innovative voltmeters go the extra mile and offer a digital battery pack monitor that consists of a unique counting feature and that measures the remaining capacity of the battery packs in the EV with either volts, amps or amp hours as their metrics.
Other features that come with todayís available voltmeters include the ability to offer alarms at low and high voltages; a current input thatís expendable to about 9999A with its shunts; and a display interface that shows not just voltage, but also the consumption and charging current and ampere-hours (amp-hr) of the EV. Another important tip in finding the right provider of voltmeters today is to rely on brands that are known to provide accurate data when the EVís fully operated.