How to Power a 50W Led with a Car Battery

Power 50W Led With Car BatteryI love the super bright LED lights. They are far more energy efficient than your common incandescent lights. Unfortunately they’re designed to use between 30 and 34 Volts.

That’s OK as there are many ways to get the voltage necessary to power this light.  However, the most cost effective way to put together a circuit like this is to look for technologies that are common place.

For example, 12 volt components are very popular. They’re designed to run off of 12 Volt batteries which are also very popular.

In a project that I worked on, I evaluated a boost converter for use with one of these high power LEDs.

About the 50W Super Bright LED

50 W LEDAs mentioned, this light is designed to work on voltages that are between 30 and 34 volts.  At 30 volts it pulls about 1.7 amps and at 34 volts is draws about 1.5 amps.

The brightness of these types of bulbs ranges between 4000 and 5000 lumens. In other words, each watt of power provides between 80 and 100 lumens.

Your typical incandescent lamp does not provide much better than 18 lumens per watt. In other words to get 4000 lumens of brightness out of an incandescent bulb, you would need a 222 watt bulb…. and that’s with the best of incandescent bulbs. Most aren’t that good.

More, the LED bulbs typically last for more than 50,000 hours. The low end incandescent lights can last for 1000 hours while the high end flood light variety claim that they will last for 20,000 hours.

Me? I settled on the 50 watt LED that you see below. At less than 10 bucks, it even compares with the cost of incandescent and fluorescent lights.

You can buy one here.

The 150W Boost Converter

Boost Converter PictureIn order to make the LED power up from a 12 volt car battery, you will need to convert the 12 volts to somewhere between 32 and 34 volts. To do that you will need a boost or step up converter.

I chose the one you see pictured below. It provides more than enough power to do the job and it is inexpensive.  If you wish to know more about it,  you can read my 150W Boost Converter Review.

You can buy one here.

Adjusting the Boost Converter

The 150W boost converter can be adjusted to provide an output between 10 and 34 volts DC.  To operate the LED,  we will need somewhere between 32 and 34 Volts DC.  I adjusted mine for 33 volts.

Connect your car battery to the boost converter input and monitor the output with multimeter.

While monitoring the multimeter, adjust the output potentiometer until the meter reads 33.0 Volts.

Adusting the Boost Converter

Wiring Up The Boost Converter

Wiring is simple.  Just connect the light as pictured above.

For what it’s worth,  I used 14 gauge wiring from the battery to the boost converter and 16 gauge wiring from the boost converter to the light.

If this were a permanent installation,  I would probably fuse the battery output with a 15A fuse and the boost converter output with a 10A fuse.

Wiring Boost Converter

The Boost Converter and LED Wired Up

Below is a picture of my system wired up. The positive lead is not connect to the car battery yet, so the lamp is not lit.

See that chunk aluminum that my light is screwed to?

That’s a heat sink. The 50 watt LED generates a lot of heat and we need a way to dissipate that heat. Providing a heat sink thus needs to be a design consideration for any permanent project you assemble.

50W Led Connected Up

The LED Powered Up

This picture shows my light powered up.

What you can’t appreciate is how bright it really is. In fact, you will temporarily blind yourself by looking at it for too long with a naked eye.

50W LED Lit Up

Available Here


  1. Franco December 11, 2016
  2. Diego Ortiz December 9, 2016
  3. haydar May 16, 2016
  4. May 13, 2016
  5. Carl May 6, 2016

Leave a Reply

Your email address will not be published. Required fields are marked *