My backup LED light project

I own a 05 BMW M3 and one of the cool things about it is the rear lights are all LED's except for the reverse lights! I thought it would be cool and fun to make some LED backup lights so everything would be LED

I found a site selling LED bulbs and ordered them. Once I got them I was disappointed with their output and quality. Shortly after I discovered DX and then CPF forums. I read and read and set out to make a PROPER LED backup light

I ordered some XP-G R5 drop in P60 pills and converted them to the car style plug in adapter and the result is awesome!

Left aftermarket "cluster" LED, Right XP-G




Below is comparison of the XP-G and the aftermarket LED bulb! I think you can guess which is which


And both together!!


Quite a dramatic difference! :thumbsup: I'll have night time shots later tonight.

Also I measured amperage draw of the XP-G and at 12 volts it was pulling around 500ma. So that should be 6 watts right? How do I calculate current at the emitter after the board?

I think the next step is to get a proper buck driver that will run the XP-G's @ 1400-1500ma.

-Chris

How is the current limited in the current config?

12v at 500ma means 6 watts dissipated in the light unit. It is going to get hot. Don't leave it in reverse for more than a minute. Keep in mind that when the engine is running the voltage can be as high as 14.5.

I wouldn't go 1500 ma unless heat sinking is better or you don't use reverse for more than 30 sec at a time.

This thread is probably better fitted for the automotive section.

JohnR66 said:

How is the current limited in the current config?

12v at 500ma means 6 watts dissipated in the light unit. It is going to get hot. Don't leave it in reverse for more than a minute. Keep in mind that when the engine is running the voltage can be as high as 14.5.

I wouldn't go 1500 ma unless heat sinking is better or you don't use reverse for more than 30 sec at a time.

This thread is probably better fitted for the automotive section.

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There is a buck/boost driver limiting voltage, capable up to 18V so I am safe.

It looks AWESOME!!! :thumbsup::thumbsup::thumbsup::thumbsup:

One question: How did you attach the drop in pill to the bulb socket? It looks rock solid!!!

That is brilliant! Aside from the heatsinking problem, but who drives in reverse for more than a minute anyway.

A better picture of the socket connection to the drop-in would be great

M52 POWER! said:

Also I measured amperage draw of the XP-G and at 12 volts it was pulling around 500ma. So that should be 6 watts right? How do I calculate current at the emitter after the board?

I think the next step is to get a proper buck driver that will run the XP-G's @ 1400-1500ma.

-Chris

Click to expand...

without knowing the efficiency of the driver you could only guess.. perhaps 4-5watts to the LED or about 60-80 percent efficiency. From what I have seen (stats) buck circuits tend to be more efficient when the voltage difference is small between the LED and input.

Lynx_Arc said:

without knowing the efficiency of the driver you could only guess.. perhaps 4-5watts to the LED or about 60-80 percent efficiency. From what I have seen (stats) buck circuits tend to be more efficient when the voltage difference is small between the LED and input.

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I think the only way to be sure about the led driving current is measuring directly on the led. Voltage and current! I don't think that a cheap drop-in could use more than 1amp on the led...

The socket is connected to the pill by solder. I sanded the edges of the socket and then ran a thin bead of soder onto it. Then I joined the 2 together using solder. It worked better than I had even hoped

Installing high watt leds in your reverse lights without diffusing the outcoming beam isn't that brilliant idea.It is very annoying for every vehicle/driver that is behind you and i am sure you are aware of it.

I like it & would also like more reverse lighting.

I don't see the 'bright reverse lights' being too much of an annoyance to other drivers. It sure seems rare that I go backwards when somebody is behind me. Also, if you watch people drive, you will see that nobody pays attention anyways....so it's even less likely to be a bother.

I suppose different countries define different attitude on this matter ..
Plus driving an SUV(generally speaking) makes difficult to understand what a low-height car driver feels. Further more ,here where i live ,reverse parking procedure is common (if not the only way) on the street - no garages.

daf3m said:

I suppose different countries define different attitude on this matter ..
Plus driving an SUV(generally speaking) makes difficult to understand what a low-height car driver feels. Further more ,here where i live ,reverse parking procedure is common (if not the only way) on the street - no garages.

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There you go, two different perspectives based on differing circumstances. This allows us both to be right for our particular situations.

I experimented with different reflectors and even no reflector. Surprisingly WITH the stock drop in reflector produced the best spread/focus out the back. They actually have a decent cutoff which shouldn't blind people.

M52 POWER! said:

The socket is connected to the pill by solder. I sanded the edges of the socket and then ran a thin bead of soder onto it. Then I joined the 2 together using solder. It worked better than I had even hoped

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Thanks for the information, and again, let me tell you that it looks absolutely incredible!!!

12Johnny said:

Thanks for the information, and again, let me tell you that it looks absolutely incredible!!!

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can't seeing anything.....

Its not like we drive around in reverse all day. And the lens diffuse/block enough of the light. Annoying is good since they'll pay attention and not crash into me! Backing out of the driveway and parking spots is now safer!

I have high-powered LED backup lights from Vleds. They are the 8-watt 921 sized. Still couldn't see in reverse at nighttime. Now, the VLED 18watt license plate frame is awesome and makes backing down a 200 yard pitch black driveway a piece of cake! Had to use the 8-watt 921 replacements to 'source' power to power the license plate frames. Normal 921's incan's are 18 watts. So, from 36 watt incan to 24-watts of LEDs on same circuit. Less power,more light, ands its pretty much stealth vs. using bolt on rear fog lights!

A LED/driver mounted to the license plate(great heatsink) is something I am considering on my other car. Waiting for my P7's and drivers to come in for my outdoor yard flood light. Wonder if anyone will notice an LED sticking out a hole drilled into the license plate.

deadrx7conv said:

I have high-powered LED backup lights from Vleds. They are the 8-watt 921 sized.

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It sounds great, and we would LOVE to see some pics of your setup!

deadrx7conv said:

Wonder if anyone will notice an LED sticking out a hole drilled into the license plate.

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I am sure that nobody would pay attention to it, except by night, when you back up! The problem would arise when it rains, as it would not be waterproof? :naughty: