Introduction: LED Rose Bouquet-Powered by a 5 Volt Portable Phone Charger

About: Working on building a startup company in Upstate N.Y. Idea is crafted obsolete-proof electronics, a sort of blend between art and science. We do repairs and services in all things electronics, as we develop a …

Light up those silk roses with a common portable phone charger! 9v batteries die and usually end up in the trash. 2032 button cell batteries can be a challenge to find locally at a good price and require a battery holder. We'll show you a great gift idea for that special someone- one which they will easily be able to keep charged up and proud to show off with only with the click of a button.

Step 1: Step One: What You Will Need

Anybody can buy roses, but If you really want to see their eyes sparkle, this is the way to go!

This is a project you can build with some fairly easy-to-find supplies and tools and when all is said and done, it is possibly more beautiful than real roses and it might just cost you much less. All it takes is that time you put in, which makes it all the more of a great gift.

So, let's get started!


6 Silk/True-touch Roses

Portable Phone Charger Bank

18 LEDs

18 Resistors

Green Magnetic Wire


Glue Sticks

Usb Wire

5 Volt Micro USB Charger Plug


Micro Slide Switch

Filler Flowers


Soldering Iron

Third-hand Tool

Glue Gun

Nippy cutters

Wire strippers



Jeweler's pliers

Series/Parallel LED-Resistor calculator (I used )


Adequate ventilation

Safety Glasses

Use the right tools for the task at hand

Take your time, stay aware, have a fire extinguisher handy and have fun!

Some things are worth noting as far as the tools and supplies:

  • Roses differ in quality-shop around and see if you can find ones that feel almost real, because some are made of a dyed cloth and the colors can run if they get wet. Also darker colors do not diffuse light as well as lighter colors, especially when there are many layers of petals.
  • Green magnet wire-is great because it is very thin and blends in, but also because it has an insulating paint which allows wires to be run next to each other up the stem without shorting out the circuit.
  • Do the math before purchasing supplies-using a calculator such as the one suggested(or by hand, using ohm's law). I used the smaller pink 3 mm LEDs(2.3V, 28mA) and a 5V, 22,000 mAh charger bank. Type in the Forward Volts and Current draw of the LEDs, the Voltage of the charger (5V) and number of LEDs and out comes your answer for the best resistor configuration to use. The one I use here is 82 Ohm resistors, one per LED and all in parallel.
  • Testing- at each step, with a couple of batteries, because if something goes wrong, (such as wires shorting out the circuit or magnet wire not being soldered fully to the LEDS) then you will know right then where the problem exists, instead of ripping flowers apart, diagnosing to the point of frustration.

So, with the parts, supplies and considerations made, lets get to it!

Step 2: Step Two: Wiring the Circuit

*Your calculated configuration may differ, but I will show you the most common.

For each set of three LEDs, twist the anodes together (these are the longer of the two legs, through which charge flows into and then through the LED)

On each Cathode(the other leg of the LED), twist on one resistor leg. These are bidirectional so it doesn't matter which resistor leg you twist on. It will be looking like there are three tentacles now.

Clamp this on your third-hand tool (or first, make a third-hand type tool!).

Wire the loose resistor legs together (Now you have a one pathway in going in, and one pathway going out).

Measure generally the length from the rose bud to the bottom of the stem. Best to overshoot this and have extra wire. Cut and collect altogether the 12 lengths of this measured wire.

Grab two wires to start with. Scrape a bit of the enamel paint from the ends, about an inch. I use a razor to do this, but stay aware and don't cut yourself. This will expose the copper so that it can be soldered.

Wrap one wire to the twisted anode side and one to the resistor side. I like to use tweezers for this for better placement. Now we have a wire going in and a wire coming out.

Solder all your joints. Use your nippy cutters to cut off the excess leg metal and wire, which would otherwise increase resistance of your circuit slightly dimming your light.

Shave some paint off from the other ends of your wires and test your circuit. If it lights up, then hot glue over all of the metal of the circuit. This helps to protect your circuit and also prevents the wires from getting squished together and shorting out your circuit later.

Neat! your first LED package is done! Five more and you're onto the next step!

Step 3: Step Three: Running the Wire

There's a bit of an art to this step. Mostly these buds will pop off the stem with a bit of a firm tug. Make sure your hands and work surfaces are clean, so as to keep the rose in good shape.

Start to explore your petals, gently peeling them back. There is most likely a bit of glue holding individual petals together, and a little bit of an easy pull will liberate each petal.

In the center, there is usually a conical piece of Styrofoam. I loosen the petals around it, and pull it out bottom-up so as to free it from the last center petal.

Cut the top off the Styrofoam, so as to have a base left to hold the stem and rosebud and yet leaving room for the circuitry.

Run both wires through this piece of Styrofoam, then through the hole of the bud. Push the stem through the bud and Styrofoam base, to connect it all. set up the LEDs pointing upwards and outwards. Glue just a bit under the base, where it meets the inside of the bud. Glue LEDs to the stem and to the Styrofoam.

Test out your circuit and see if it still works. Sometimes pushing the stem through might short the wires out.

If it lights up, then try to fold your flower together, using as little glue as possible. This reduces mess, and too many glue points can effect the end result of the light's diffusion. Not much is really needed, maybe 4-6 glue points.

From there, I use a little bit of glue to adhere the wires to the stem. Less is better of course, and when some glue dries into a whitish color, I run the hot end of the glue gun slowly along the stem. This remelts the glue a bit and helps to touch it up,making it look more consistent.

I stop gluing after about 3/4 of the way down the stem and wind the wire around temporarily so as to prevent them getting tangled up.

5 more of these and you're almost done!

Step 4: Step Four: Add Power

Now you have 6 flowers all individually wired.

This is a good time to add your filler flowers if you have them, and to arrange your flowers . It's an art form, all itself. I wind something around the stems in a couple of places to prevent them from moving around and getting boggled up as I carry out the rest of the project.

Now it's time to twist all your positive wires together and all the negative wires together. Test these out and see if all your flowers light up, then solder. Now you have one wire in, one wire out. All your LEDs are in parallel.

Now snip your USB end clean off the wire, leaving some wire to work with. Strip a bit of the outer sheath off. You now have most likely 4 small wires, maybe some other junk (loose shielding, thread). Only thing we need is the black wire and the red wire. Strip a little off each and cut away the rest-no need to "ground out" the green and white wires or anything like that. Solder up the tips of the red and black wires. Now you have a positive, red and a ground, black.

Twist and solder your negative magnet wires with the black and the positive wires to the red. (If your portable charger does not have a power button, like mine, this is where your switch with go, between the negative wire and the black ground.)Tape wires separately, making sure they are insulated from each other and will not touch even after being messed with. You can use heat shrink if you like. I like to then tape these wires together and get this all put together in such a way that it can take a beating. This is the part of the rose bouquet that is going to see the most handling over time.

So, is it charged up, and is it ready? Click the button, here goes nothing!

Step 5: Step Five: Final Touches

You might find, especially if you kept testing as you went, that it all lights up very nicely.

If not, it's time to diagnose why. If you tested each flower individually, and they worked, then of course the issue is near the USB end. Make sure your portable charger works on other devices. I've accidentally mixed my wires up and had a couple of positives where negatives should be. I just snip the green wires near the USB end, clean it up and strip green wires, and try again.

If your flowers are all lit up, it's all just a matter of tying the portable charger to the stems a bit. I use some ribbon. From there, maybe clean up your arrangement and wrap it in some paper maybe...

Valentine's Day Challenge 2017

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Valentine's Day Challenge 2017