# What are amps? And how to measure amps with a multimeter?

In the home and industry, as long as electricity is involved, the concept of amps is bound to be involved. Amps size determines wire size, which is especially important for the design of the battery internal structure. The maximum discharge amps of the RV battery also determines the maximum load on the entire system. So it’s important to know about amps.

## What are amps?

An amps is the unit used to measure electric current. Current is a count of the number of electrons flowing through a circuit. One amp is the amount of current produced by a force of one volt acting through the resistance of one ohm. If you were to think of electricity as water through a hose, amps would be the water.

Imagine electricity flowing through a wire. Amps describe how much electricity can flow through the wire, this is known as the ‘electrical current’. If not much electricity can flow through the wire then the amps are a low number; if lots of electricity can flow then the amps are a high number.

## How to measure amps with a multimeter?

### 1. Hall Sensor (Amp Clamp)

Ampere clamp, just clamp the wire to measure the current in the wire.

The meter uses strong iron clamps to hold the conductor under test tightly to concentrate the magnetic field around the conductor. When current flows through the conductor, the magnetic field passes through the Hall-effect clamp meter and generates a voltage, which is converted into a digital reading on the meter.

Hall sensors get their name from the term “Hall Effect” that the sensor uses to determine the strength of the current. The term “Hall effect” is the property of directing current flow in a conductor. A Hall sensor (or Hall effect sensor) is an ampere clamp meter that measures both AC and DC current.

### 2. Multimeter

#### Measurement of DC Amps

Insert the black test lead into the “COM” hole first. If measuring the current greater than 200mA, insert the red test lead into the “10A” jack and turn the knob to the DC “10A” level; if measuring the current less than 200mA, insert the red test lead into the “200mA” jack, turn the knob on to a suitable range within 200mA of DC. String the multimeter into the circuit, keep it stable, and you can read it. If the display is “1.”, then the range should be increased; if “-” appears on the left side of the value, it means that the current flows into the multimeter from the black test lead. When you install the home energy storage system, you will need to use multimeter to test the battery DC Amps.

#### Measurement of AC amps

The measurement method is the same as before, but the gear should be switched to the AC gear. After the current measurement is completed, the red pen should be inserted back into the “VΩ” hole.

## How to calculate amps from watts？

### DC Watts to Amp Formula

The current I in amperes (A) is equal to the power P in watts (W) divided by the voltage V in volts (V):
I(A) = P(W) / V(V)
So, amperes are equal to watts divided by volts.
Amps = Watts/Volt
or
A = W/V

For example,
With a power consumption of 330 watts and a supply voltage of 110 volts, what is the current in amps?
I = 330W/110V = 3A

### AC single phase watt to amps formula

The phase current I in amperes (A) is equal to the active power P in watts (W) divided by the power factor PF multiplied by the RMS voltage V in volts (V):
I (A) = P (W) / (PF × V (V) )
So, amperes are equal to watts divided by power factor times volts.
Amps = Watts / (PF × Volts)
or
A = W / (PF × V)

For example,
When the power consumption is 330 watts, the power factor is 0.8, and the RMS voltage supply is 110 volts, what is the phase current in amps?
I = 330W / (0.8 x 110V) = 3.75A

## What size wire for 100 amps？

As the safety of the copper wires carrying capacity of 4-8 Amps/mm2, the safety of the aluminum wire carrying capacity is 3 ~ 5 Amps/mm2, So 100Amps=100/4=25mm2 copper wires.

## How many amps will cause damage to human body?

In general, can through the body of the safety current of 0.01 Amps.Because people can afford safe voltage is 36 v commonly, when voltage is 36 v, through in the line of current only 0.01 Amps., as long as there is no more than 36v voltage, the body will not being hurt by the current, so the minimum safety current of 0.01 Amps. When the voltage larger than 36V and Currents more than 0.01 Amps, the electricity will cause damage to people.

Relate articles:

For any battery-related questions or problems you may have ELB Battery are here to help, just email us at info@ecolithiumbattery.com or just contact us here!

Want to produce customized lithium battery according to special requirement, welcome to consult ELB team to get more details.

THE ELB BRAND PROMISE

QUALITY

4000 TIMES CYCLES 10 YEARS DESIGN LIFESPAN

CERTIFICATION

ISO9001:2015,ISO14001:2015,OHSAS18001:2007 CE, CB, UL, KC, FCC, BIS, IEC62133.

SERVICES

EXW, FOB, DAP, DDP OPTIONAL
T/T, L/C OPTIONAL