Battery powered arduino + high power leds?

I'm desperately trying to design an arduino circuit that can power each color of a high power cree MC-E color RGB led.

What is the smallest dimension rechargeable battery I can use to accomplish this and have it run for a few hours?
I'm desperate!

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maewert6 years ago
Hey Spiffy,

You want to run each color of the LED with somewhere between 400 and 500 milliamps or so.  I'm guessing that you are using a LED driver or something like:
https://www.instructables.com/id/Super-simple-high-power-LED-driver/

With the effeciency of the system it will take a rather large battery.

I hope you are not trying to make one these using a power LED:
http://www.youtube.com/watch?v=Sqq0doh7Dto


(these are cool by the way!)

If so, then I would use two standard RBG LEDs instead.  I would think high-power LEDs would give you a lot of design problems.  You probably could use a barebones arduino (or an ardweeny board) powered by a few watch batteries.  Two RGB LEDs could then be connected to 6 digital outputs which provide PWM (pins 3, 5, 6, 9, 10, and 11) via 220 ohm resistors or so.

I hope I haven't misread your intentions!

Best Wishes
SpiffyChee (author)  maewert6 years ago
haha I'm actually trying to make LED poi/glowsticks, but that was a good guess. So if I use normal RGB leds wouldnt the arduino still not be able to put out enough current?

I want to use Leds that are as bright or brighter than the inova microlights or photon freedoms. Do you know any specific leds that would be this bright?
I'm not familiar with those lights. 

The inova microlight appears to be a standard white super-bright.  Same for the photon freedoms except they offer different color LEDs.

I have worked with 'super bright' LEDs that take around 20 milliamps or so.  The Arduino should be able to provide the ground to these LEDs.  The tricolor LEDs give 1000 mcd - 5000 mcd or so per http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fleds.htm#fivemm.

Take a look at the other higher-brightness LEDs there as well.  I wouldn't be surprised if these were the same LEDs as in the minilights you identified.

I am sure your high-power LEDs will outshine these little guys!

In general Identify the amps needed by your high power LEDs then figure out how many amp-hours your battery will need to supply then determine the battery size given the specific battery's technology you choose.

Best Wishes.
SpiffyChee (author)  maewert6 years ago
thanks for all your suggestions! One more quick question.
Would a 2500mAh 3.7volt battery work for me? (like this one: http://www.dealextreme.com/details.dx/sku.5790)

Would it be able to power superbright leds and the arduino with just one battery? Or would I have to use 2?

Or if I decided to go the high power led rout, would that same battery work? or 2?

There is something I'm not understanding out powering both the arduino and the led's from the same power source... I just don't know what I don't know... lol

Some arduinos can work with 3.3 volts, such as http://www.solarbotics.com/products/50710/.  Other arduinos require 6-9 volts or so, so for these you'd need two batteries or a DC-DC converter to turn the battery into a higher voltage.  The 3.7 v battery would power the superbrights just fine.  the battery would go the the LED, then the other LED wire could go to a resistor, and then into one of the arduino output pins.  When the arduino set the output pin to LOW, the pin goes to ground and the LED lights up.

I'm not familiar with your high power LED to give advise there :-)
I forgot to add that if the current requirements are too great for the arduino, you can easily add some switching transistors and resistors.  These inexpensive devices (like the 2n2222 transistor) can easily take ~100 milliamps to drive several of the superbrights taking the load off of the Arduino (but not the high-power LEDs, these guys can suck down 3 watts or more!).