# Help with SMD LED's and power!



## wiltron (Apr 1, 2013)

Hey guys,

I’m a beginner and I’m looking for help with power and LED’s. I don’t know much about currents, watts and etc, but that’s why I’m here, to get advice from the experts!

I had recently purchased a 2011 Kia Optima and I’m looking to install LED’s into my car interior. I have been looking on ebay to buy some LED’s for cheap but ran into some question marks! I want it to be the brightest possible and did some research. I noticed that 5050 SMD LED’s would be the best.
Is it possible to have 1210 SMD LED’s brighter than 5050 SMD LED’s? 

Anyways,I had taken my car bulb out and it looks like there are festoon and T10 adapters. Some of them say 12v 10watt and some say 12v 5watt. I’m assuming I probably shouldn’t go over these power ratings...or maybe certain areas don’t need to be as bright and they used less wattage bulbs?

I looked on ebay for some LED’s and it seems like they all should work on my car, but in some of the compatibility checks on ebay, it says it won’t work. At the same time, I don’t trust the accuracy of these compatibility ratings.

I have found these SMD LED’s for very cheap:
_*Link to ebay removed by Greta - please refrain from posting such links. Thank you._

I don’t know if the quality from these cheap Chinese brands will differ from any other LED’s I look for on ebay but these are what I’ve found so far.
To my main point, I was wondering if anyone knew if these would work in my car before I buy a dozen of them without ruining the electrical system. It shows 12 volts but doesn’t say watts. I had asked the seller and he said it was about 0.25watts per LED, so if there are 12, it would be 3 watts total. I’m assuming since it is less watts, it should be okay to put in? Or is there something else I don’t know about?!?!?

Also, if I get one that has 18 LED’s, would that be 4.5 watts and that should still work in my car? ...assuming the answer to the last question above is Yes.

Will these lower watt LED’s be brighter than my regular yellow car lights?

People also say, don’t buy china brand LED’s....so what do I get?
I saw these: _*Link to ebay removed by Greta - please refrain from posting such links. Thank you._
These aren’t China, they are Japanese? Is that better?

Any tips or hints? Please help! Thanks guys.

Cheers,
Wil


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## JohnR66 (Apr 2, 2013)

I agree. Don't buy cheap Chinese LEDs. I have bought and tested many over the years with a light meter. They often have poor output, lousy color (too bluish) and poor life. Buy your LEDs from a place like Digikey or Mouser.

I converted my dome light over to LED using a Bridgelux LED array. I used a 9.6 volt array in series with a 20 ohm resistor (two 10 ohms resistors to spread dissipation). It is undertriven at around 200ma, yet is far brighter than the bulb it replaced that needed over 1 amp. I didn't have to hack up my dome fixture to fit it in either.


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## cybhunter (Apr 8, 2013)

It is technically possible for a 1210 to be brighter than a 5050 although the problems of current management and heat displacement become apparent and need to be addressed. Ideally you'll want to look at the spec sheet for the LED in question to determine at what current draw will produce (as a percentage of its max rated light output) how much light.

On page 17 of the BridgeLux Es White Paper, it shows the relation between the current and the luminous flux, while on page 20, it shows the current/voltage relationship. These are the most important graphs to look at when replacing the lamps 
http://www.bridgelux.com/assets/files/DS23 Bridgelux ES Star Array Data Sheet DS23 120312.pdf

Hope this helps
Joe​


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