EVSE Open Control Technology vs. Closed Protocols

Advantages of Open

As with any technology, there are two schools of thought in EV charge management – EVSE - open control technology vs closed protocol.  A quick search will show that there are many complex definitions of “open technology” that mostly apply to software systems and hardware platforms.   However, I prefer a simple definition:  An “open” technology is one that provides users knowledge and access to the underlying system.  Applying that definition to EV charge control suggests that an “open” system allows external control of the charge cycle without relying on licensed software services or proprietary hardware.  In contrast, a closed protocol system forces reliance on the manufacturer’s software or provides no control at all.

There are numerous manufacturers of EV Chargers (a.k.a. electric vehicle supply equipment – “EVSE”) that range in amperage and controllability.  Most residential grade EVSEs lack the ability to externally control the timing and amperage of a charge cycle, but those that do require use of a proprietary phone app or website.  Commercial EVSEs more frequently offer control, but it’s normally limited to credit card authentication and inaccessible outside of the vendor’s system.

In my opinion, purchasers of a closed EVSE expose themselves to future risk.  As we have all learned, companies and their technologies come and go.  A new market entrant might provide attractive solutions to further optimize charging or provide better monitoring that may be unavailable on older equipment.  Worse yet, a closed platform vendor could keep some or all of the savings their customers earn through smart load management strategies such as demand response, peak load management or off-peak charging.   Finally, closed systems can become obsolete.   In my controls practice, I’m often asked to connect to older proprietary systems, and frequently it’s not possible.  How many times have you learned that a technology has reached end-of-life and therefore is no longer supported without a costly upgrade?

ClipperCreek Open Integration

ClipperCreek's CS100 and HCS40
ClipperCreek's CS100 and HCS40

Unlike most of its competitors, ClipperCreek’s CS and HCS chargers offer users the option to easily integrate external controls.   The user manual has clear instructions on how to interface with the unit, and their technical support department will gladly guide you on its usage.  The CS line has a 10+ year history and proven track record while the HCS line offers a more modern look and advanced control features.  Both versions allow external control to manage when and at what intensity (amperage) that a vehicle charges.  The CS units offer two digital inputs: HiOff which provides the ability to start and stop charging (perfect for delayed charging) and HiLo which provides the ability to limit amperage to 10% of rated (perfect for load control).  A standard HCS unit includes the ability to control when charging occurs, and when ordered with the optional COSMOS® interface, the HCS offers more granular load control by allowing an external controller to set charging at 0% (off), 25%, 50% or 100% of rated load.

Full Disclosure:

Control Dynamix’ peak load management system, EvAuto, was designed to use ClipperCreek’s open technology to control vehicle charging.  Therefore, I must admit to some bias in ClipperCreek’s favor, but I truly believe that open systems are in the customer’s best interest.  I believe that by purchasing an open system, our customers have future proofed their charge environment. The fact that our system can easily be replaced forces us to keep EvAuto current because we know that our customers can replace our system without having to replace their EVSE.

Control Dynamix created EvAuto to provide control and monitoring for fleet electric vehicle charging.  Our systems are accessible via a standard web browser, and they can be hosted on either a local controller or web server which can be supplied by the customer or hosted by us.  With the exception of our proprietary control algorithms, the system is open for users to manage and modify.  Our control technology platform runs on an open-licensed Tridium Niagara system so customers have the option to replace our software from any Niagara vendor.

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