How to Build a Cool EV Charger

I built an EV charging station using a car wheel! All EVSEs or EV chargers as everyone calls them look pretty much the same; a rectangular box, sometimes with a screen, sometimes without, maybe a few LEDs to show charging status but that’s pretty much it. I wanted to make a charging station that stood out, that would look amazing on my garage wall, something I could personalize. Using OpenVolt hardware, I built a charging station out of a Rotiform wheel that lights up in any color I choose. Here are the steps to follow if you would like to do the same.

• Wheel of your choice. I used a Rotiform wheel
• Wheel Mounting Brackets by OpenVolt
• Custom Built LED Wheel
• EV charging station or controller by OpenVolt

The OpenVolt controller is designed to act as an EV charger controller. It has room for an extra PCB(ESP-01) that can be plugged in to control a string of LEDs. We will be using this feature to control our custom LED wheel.

• Find an appropriately sized enclosure. In my case I am reusing an aluminum enclosure from an old charging station. 
• Mount the OpenVolt controller and your power relay on the inner mounting panel. I am using a Struthers Dunn Power relay, rated for up to 50 amps. The controller has 4 mounting holes, I am using 4 aluminum standoffs. It is important that the standoffs are aluminum, since they are conducting and 2 of the mounting holes on the controller are plated, these are grounding the controller to the rest of the enclosure.

• Make appropriately sized holes for your cable glands. You will need 3 holes, 1 for the input cable, 1 for the J1772 output cable and a third smaller hole for the LED control cable.

• Route the input cable through the leftmost cable gland, I am using a cable with a NEMA 6-50 plug. NEMA 6-50 is the outlet I have available, but you can use a different type of cable as well. This cable has 6 AWG conductors inside, which we will terminate to the input side of the power relay and ground.

• Route the output cable through the second cable gland and terminate the wires to the output side of the power relay. Make sure you run the wires through the current transformers before terminating them onto the relay terminals. 2 of the current carrying conductors go through the GFCI current transformer and only one goes into the current measuring transformer. I am using a standard J1772 cable assembly, but you can use an NACS(Tesla) cable as well. Connect the current transformers into the controller PCB and the Control Pilot wire into the terminal block labeled PILOT

• Plug in the cable that goes to the top connector on the controller PCB

• Connect the leftmost wires on the connector to the input side of the power relay

• Connect the rightmost wires on the connector the output side of the power relay

• Plug in the cable for the bottom connector (J3) to the controller PCB and connect the wires to the coil of the power relay

• Connect the LED power/control cable into the terminal block on the PCB controller. Brown is positive 5VDC, blue is the data line and black is reference for 5VDC. The other side of the cable has a 3 pin connector, the connector type is not important as long as it has 3 pins. This will connect to the custom LED wheel in a later step

Depending on the type of enclosure you picked, you might be able to install the lid on the enclosure first. The enclosure I have has mounting holes that are accessible without the lid installed.

• Mount your enclosure on the wall

There’s 2 brackets, each piece has 2 mounting holes. The bottom bracket has space to let the cables run down. It cradles the wheel and the top bracket clamps it to the wall. The bottom bracket has a small level for ease of installation as well.

The following steps will be the same for any wheel you pick, but the parts will slightly differ depending on your dimensions. I picked a Rotiform wheel. Measure your inner barrel diameter, you will also need to know your wheel bolt pattern.

Your inner barrel diameter will be the size you cut your LED panels. The LED panels are acrylic or polycarbonate panels, 1 opaque and 1 frosted piece to diffuse the light coming out of the LED hub.

The frosted panel will sit on top, the white panel on the bottom and the LED hub in the middle. The LED hub is a 3D printed piece used to hold an addressable 5V LED strip. It has the same bolt pattern as the panels

• Peel the adhesive backing from the LED strip and adhere it to the LED hub
• Solder a 3 conductor cable to the end of the LED strip and run the cable through the channel in the hub

• Stack the components as follows, white panel, led hub and frosted panel on the top

To clamp the panels together I am using 10mm bolts and 3D printed inserts

The LED wheel assembly can now be installed on the wheel. I am using 3D printed wheel nuts to hold the LED wheel to the Rotiform Wheel. The other end of the cable from the LED strip has the mating connector to the one used in Step 1.

The wheel can sit on the bottom bracket while the top bracket is adjusted to clamp the wheel against the wall

• Next, connect the LED cables together, the one coming from the enclosure to the one from the LED hub

The cable can be tucked in behind the wheel for a cleaner look

Once the controller is powered up, the LED controller can be accessed via WIFI. It can be lit up in a variety of colors and effects. I’ve even set it up so it glows RED when the EV charger is ON and pulsing green when my EV is plugged in and charging. The LED controller is an ESP-01 board plugged into the OpenVolt controller. The ESP-01 is running WLED, you can learn all about that here.