How to Determine the Amperage Draw of the 55-Watt Halogen Area Light with H3 Style Bulb


what is the amperage draw of this light? I am looking for an area light to install on my cargo trailer when i came across this light. I would like a bright light... do you stock any comparable lights with a low amp draw?

Expert Reply:

The 55-Watt Halogen Area Light, item # QH75ISB, draws 4.5 amps per light. There is an equation we can use to determine amperage when watt rating and input voltage is known. Amperage equals Watt Rating divided by Input Voltage which is typically 12.8 volts in automotive applications. So 55 watts divided by 12.8 volts equals 4.30 amps and your specific charging system may output slightly more than 12.8 volts.

If you wire this light with a switch you should be able to use it on your trailer by wiring to the 12 volt power circuit in your 6-Way or 7-Way connector. I would not attach this light to the taillight circuit because of the amperage draw.

This light takes an H3 style replacement bulb and you should be able to find a 35 watt H3 bulb, that draws about 3 amps, at an auto parts store if that will make a difference for your application. This would still make for a pretty bright area or flood light for your application.

I spoke with my contact at our supplier and asked if there is a LED light that would make a good flood/area light and at this time the only options are the Wesbar LED utility lights with magnetic base, # 54209-017 and # 54209-018.

expert reply by:
Robert G

Ask The Experts a Question >>

Products Referenced in This Question

Product Page this Question was Asked From

Similar Expert Q&A Pages

See More Q&A Expert Answers >>

About Us
photos and videos

Original Photos & Videos

Produced to make sure you know what you are getting and you get exactly what you need.


Installations Completed

To make sure products work and fit the way they are supposed to.

etrailer call center

Phone Calls & Emails Answered

1,125,924 phone calls and 1,350,587 emails to help find the right solution.

etrailer training

Average Hours of Product Training

We get to know our products firsthand so experts can better help you.

etrailer service

Years of Quality Customer Service

Assisting our neighbors and customers, face to face at the counter.

etrailer experts

Pages of Expert Information

Created to make sure you have all the answers to your questions, from real experts.