Chargeplug
June 2022 - May 2025
The ChargePlug is a low-profile, compact, and durable J1772 connector designed for the Voltpost Platform. It features a 90-degree, low-profile cable orientation that directs the cable along the vehicle's body instead of outward toward the road. Integrated LED lighting provides clear visibility and intuitive feedback day or night.
The design emphasizes efficient manufacturing and reliability, using just three screws and a series of high-strength snap-fit features that make the ChargePlug vandal-resistant.
It was engineered to meet UL 2251 (Plugs, Receptacles, and Couplers for Electric Vehicles) and NEMA 4X standards, ensuring durability and safety in demanding environments.
I owned the design, manufacturing, documentation, sourcing, assembly, and testing of all components from detailed design through production.
ChargePlug
ChargePlugs in the wild, in the factory, and exploded views. One of these is now in the Henry Ford Museum’s permanent collection!
Drive-Over Testing
To meet the UL 2251 Standard, the ChargePlug had to survive being run over by a vehicle. Simulations helped dial in the geometry, but nothing beats real-world testing. My requirement was that an SLA 3D-printed prototype had to survive the drive-over, ensuring the final injection-molded design would pass. It took many iterations, but the final molded parts were run over repeatedly by my team. Success!
Simulation
I ran extensive Ansys simulations to optimize snap-fit features, heat dissipation, and gasket performance.
Manufacturing & Assembly Optimization
Beyond surviving the drive-over, the ChargePlug needed to be easy to manufacture and assemble. Here are several prototypes, iterations, and brainstorming sessions that informed the final design.
Electronics
PCBs, Micro-Soldering, Wire Harnesses, LEDs - the ChargePlug has it all! Multiple boards inside control the indicator LEDs, J1772 communication circuitry, and the cable mechanism. These PCBs incorporate Hall-effect sensors, a reed switch, a microcontroller, an accelerometer, and supporting communication circuits. I designed the board with the Hall effect sensor, reed switch, and J1772 communication circuitry.
Gasket Development & Ingress Testing
Because the Voltpost Platform is installed curbside, the ChargePlug must withstand the elements. I designed custom gaskets, prototyped them in-house using 3D printing and molding, and performed validation testing for UL 2251 and NEMA 4X requirements.
Snap-Fit Features
Most of the ChargePlug is assembled using high-force, fully reversible snap-fit features. Some require over 300 pounds of force to assemble or disassemble. These include annular and cantilever snap-fits designed for durability and serviceability.
Sensor Development & Testing
Hall-effect sensors and a magnetic reed switch were chosen to simplify assembly, reduce part count, and improve ingress protection. I determined the optimal magnet size and strength using a custom magnetic field calculator and hands-on testing.
Regulatory Testing
The UL 2251 Standard drove many of the most demanding requirements. Beyond the drive-over test, the ChargePlug completed crush, impact, and a wide range of electrical tests. Many were pre-tested in-house to ensure a smooth certification process.
Sourcing
I sourced all components for the ChargePlug, working closely with materials vendors, PCB manufacturers, injection molders, and machine shops. I also sourced all assembly and testing equipment. For each component, I obtained at least three quotes and compared pricing, lead times, and quality to ensure the best fit.
