Praveen Subramani design + technology + cities


With the next generation of lightweight electric vehicles being deployed in vehicle sharing systems across the world, there is a growing need for charging infrastructure that is better suited for shared vehicles, rather than private applications. smartCharge is the next generation of intelligent charging infrastructure for EVs in cities. Specifically optimized for EV sharing systems, the smartCharge platform integrates secure locking, high current vehicle charging (up to 36A), and data transfer into a single connector. Its concentric connector design allows users to insert the plug from any angle, allowing them to quickly lock and charge the rented vehicle without wasting time and space with separate docking and charging systems. The system connects vehicles to a smart charging post that integrates ambient LED lighting to provide feedback to users on the current state of charge of the vehicle, its availability status, and maintenance needs. The connection system is universally designed to function with electric bicycles, scooters, cars, and other lightweight EVs.

I led the design and engineering team for smartCharge as part of my Master's thesis work at the MIT Media Lab. Working with a team of three undergraduate researchers, we successfully built a functional prototype of smartCharge and demonstrated the product at the Spring 2012 Media Lab sponsor event.

The smartCharge prototype attached to a wooden model of a lightweight electric vehicle.

smartCharge locks and charges the vehicle with a single connector. An electromagnet with 250 lbs of holding force securely locks the vehicle to the charging station and prevents vandalism of the charge plug. The rotationally symmetric design allows the plug to be inserted from any angle -- no alignment required. This prototype connects with gold plated spring-loaded pins to copper planes with ultrahigh conductivity and can provide up to 36A of charge current, suitable for Level II electric car charging.

A user holding the rotationally symmetric connector for the smartCharge prototype

smartCharge provides a platform for ambient urban lighting with its post light cap. The cap can be set to any RGB color with a simple command, allowing information about the vehicle state of charge, maintenance needs, and reservation status to be broadcast to nearby commuters. The ambient lighting system is powered with Philips ColorKinetics technology and can be customized by cities or fleet operators to their desired color preferences.

smartCharge's ambient lighting cap can take on any color, providing intuitive information for users of shared vehicle systems in urban environments.