# How Many Amps Does a 120-Watt LED Light Bar Draw?

Whether it is in your home, car, or even your phone, anytime a light is on, chances are that it is an LED. However, today, we are going to talk about light bars and how many amperes they draw while in use. For instance:

## How Many Amperes are drawn by a 120-Watt Light Bar?

To get that figure, you will need to divide the wattage by the voltage. For instance, 120-watts divided by 12 volts gives you 10 amps. If you have the light bar plugged into a VAC, that would be 120 divided by 120 to give you 1 amp.

## What you need to know

You deciding to go the LED way is a great decision, but there are some things you may want to know now that you are in. Here are some of them.

Also read: 3-Wire LED Light Bar – White, Blue, Black – What Wire Does What? & read this article for your garage lighting on 4 foot led light fixture

### Polarity Matters

When it comes to electronics, polarity is what shows whether your circuit component is symmetric or not. LEDs are diodes and that means that they allow an electric current to flow in a single direction. If there is no flow of current, there will be no light.

Fortunately, this also means that an LED cannot be broken by being plugged backward.

LEDs have a positive side usually referred to as the anode and a negative one called the cathode. Current always flows from the anode to the cathode. Never the other way around. Therefore, a reversed LED can stop the entire circuit from functioning because it blocks the current flow.

### Moar Current Equates Moar Light

How bright an LED is will depend entirely on how much current it is drawing and that means two things. First, extremely bright LEDs will drain batteries faster seeing as the additional brightness is derived from the extra power being used.

Second, LED brightness can be controlled by regulating the amount of current used.

### Too Much Power is a Thing

When you connect an LED light bar direct to a current source, what will happen is that the bar will try to dissipate as much power as it can. Of course, too much of something is never good, and it may end up being damaged.

This is why it is necessary to regulate how much current flows through your light bar. To do that, you need to use resistors.

These control the flow of current in the circuit and safeguard your LED light bar from drawing too much current.

The best part is that you will not be required to do complex mathematical calculations to get the best resistor value.

## Bottom Line

We have already answered how many amps a 120-watt LED light bar will draw under normal circumstances but as you have seen, the light will try to draw as much current as it can. That can cause damage to it and what you want to do then, is to regulate the current that can be drawn.