Bluetooth Skateboard Controller Update!

I have successfully produced 4 prototype electric skateboard controllers. Here are the specs:

  • Modes: Car/Boat and Electric Skateboard
  • Sensitivity: 1000 degrees
  • Input Voltage: 4.5~6.5 VDC
  • Max Voltage Measurement: 55 volts
  • Failsafe: Slowly turns off the motor
  • Dimensions: 50.0 x 38 x 12mm

These controllers are almost ready to ship. All that’s left is to waterproof each circuit using epoxy resin, and ensure compatibility across all Android devices.

Read more

Connecting the cells

Testing and Tabbing

As stated in the previous post, the next step is to ‘tab’ the cells. To do so, I had to check if the cells were working (had any voltage). Under the 60w bulbs in my room, each good cell got around 0.2 volts. I made sure each cell doesn’t have any cracks either, as I wanted the best cells to minimize damage later on.

I used the flux and applied it to the length of the two lines, this is where I was doing to connect both of tabbing wires. The tabbing wires are the short wires ~3mm in width. I cut them to slightly more than 16cm to compensate for the spacing between each cell.

After I fluxed, I applied some solder by heating the panel with the iron, then I applied the solder. Keep in mind that even though the cell is very fragile, it can withstand a lot of heat. I did this for the ends of each white line. After that, I applied the tab strips to the ends where I just applied the solder. I used a piece of cardboard to keep the strip down while slowly moving the iron along the wire. The animated gif below should provide better detail:


I repeated this for each cell. If a tab wire wasn’t quite sticking I removed the wire and applied solder underneath.


A good idea is to create a cardboard layout where you can align the cells. I used a right angle to draw lines along the length, then I measured out the width of each cell and the spacer. Since the cell was 15 cm by 8 cm and the cardboard had a thickness of 6mm, I measured 8cm, then 6mm, then 8cm and so on and so on…


To connect the cells together I applied flux to bottom of each cell and then I applied the solder. This step was important as it is very hard to solder without the initial blob of solder. After applying the solder I folded the tab from the previous cell down, then applied heat where the white squares are located. I did this for all cells, creating two rows of solar cells. I ended up with one cell on each row that did not have contacts on the bottom. It was necessary to add two strips there as well, as they were going to be used for the bus wires.

So what the heck are bus wires anyways?


Bus wires are the slightly thicker, wider tin wires that are used to connect strings of cells together. In my cell I used three bus wires, two for the + and – and one longer one for connecting the strings together.

Remember that the bus wires still need to connect strings in series, (+ to -) so make sure you rotate one of the strings!

Now that I connected all of my cells, it’s a good time to test them out. The 150w bulb in the bathroom was nice and provided 5-6v depending on how far away the panel was.

In the next post I will be showing you how to create a base for the panels. If you have any questions be sure to leave a comment!

Read more

Materials for my first solar panel


Hi! One of my newest projects is a 12 watt solar panel made for charging my phone. Now that I have successfully tested the panel in the shy Vancouver sun, I have decided to share the build process on this website. Here is a list of things that I did:

  • Gathered materials
  • Prepared the cells (tabbing)
  • Connected solar strings using bus wires
  • Prepared the frame
  • Covered the cells in epoxy
  • Made the power connections
  • Tested it out

Things I needed:

  • Solar Cells (0.5v each at 1+ amp)
  • Tab wires (3-5 mm wide tin wires)
  • Bus wires (5-7 mm wide wires)
  • 4mm thick board
  • Wires (2)
  • 5v power regulator (I used the COM-00107)
  • Electrical Tape and/or shrink tubing
  • Rosin core solder
  • White spray-paint
  • Clear automotive coat
  • Self leveling epoxy resin
  • USB micro cable
  • Silicon

Tools I used:

  • Voltage reader
  • Flux pen
  • Table saw
  • Miter saw
  • Soldering Iron
  • Pliers/tin snips
  • Propane torch
  • Lighter

Most of these materials I had at home and did not need to buy them. However, I later realized that not many people have solar cells and spare electronic parts laying around; so I made a handy list with references to eBay:

Keep in mind that if you were to buy more efficient solar cells (say like 2 amps each) then you would need to buy a more powerful voltage regulator, otherwise your voltage regulator would overheat.

You may have noticed that I did not include all of the materials in the eBay list; this is because I personally bought them from either Home Depot or The Source (Radioshack in the States). It’s much cheaper to drive to one of these stores than pay for the extra shipping online. Also, I highly recommend searching for a solar kit as it may be slightly cheaper than buying all of the items separately.

Here is a blueprint that I made in inventor:

Solar Panel 12v Blueprint

As you can see, the solar cells are aligned in two rows and are connected in series (I will go over this in more detail later). This means that the voltage is added from every single panel, yet the current stays the same. A drawback of doing this is that if one of the cells break, then the entire current might be disrupted, and then the solar panel wont work.

These solar cells can be connected in series by connecting the bottom side (the anode or positive) to the top side (the cathode or negative). This is usually done by connecting two strips of tin to the top side of a cell, and then have it connected to the bottom side of a cell. This process is called tabbing and will be covered in the next post.

Be sure to leave a comment if you have any questions! I’ll be happy to update my post with any information I missed.

Read more