by Cartender

An open and customizable Electric Vehicle (EV) charging station for commercial and residential use

$15,818 raised

of $1 goal

Not Available
Dec 19 2019
funded on

Product Choices


Prism Core Starter Kit

(Includes VAT and other regional sales taxes.) Perfect for anyone who wants to build a custom solution, upgrade an existing charging station, or develop new features. Supports both single phase and three phase power. Includes the core Prism boards, assembled and mounted in a DIN enclosure, as well as current transformers and basic cables (no internal high current cables or EV charging cables). Post-campaign retail price will increase significantly.


Prism Core EV Kit

(Includes VAT and other regional sales taxes.) Comes with everything you need to assemble your own charging station in a custom enclosure (except for internal high current wiring, as requirements for those vary among installations). This includes a 63 A contactor, an RCD cable, and an EV cable. Backers must choose the power type (single-phase or three-phase), the charging connector (type 1 or type 2), and the EV cable length (two, five, or seven meters). Post-campaign retail price will increase significantly.



(Includes VAT and other regional sales taxes.) A complete charging solution, built around the Core, in a beautiful enclosure. The base is molded in a strong, fire resistant black plastic and the cover is a PCB sheet, specially designed to include an LED stripe and touch controls. You will receive your Prism fully assembled, ready to install and charge your vehicle. You may choose the power type (single-phase or three-phase), the charging connector (type 1 or type 2), the EV cable length (two, five, or seven meters), and the color (black or red). Prism complies with EU legal and regulatory requirements. Post-campaign retail price will increase significantly.


Prism Double

(Includes VAT and other regional sales taxes.) A complete charging solution, built around the Core, in a beautiful enclosure. The base is molded in a strong, fire resistant black plastic and the cover is a PCB sheet, specially designed to include an LED stripe and touch controls. Prism Double comes with two single-phase EV cables and can charge two vehicles simultaneously. You will receive your Prism Double fully assembled, ready for you to install and begin charging your vehicles. You may choose the charging connector (type 1 or type 2), the EV cable length (two, five, or seven meters), and the color (black or red). Prism complies with EU legal and regulatory requirements. Post-campaign retail price will increase significantly.


Recent Updates

As Featured In

Hackster News

"As well as providing an additional solution for electric vehicle owners, Prism is also looking to provide a platform for current developers to prototype and test software on."


"This is a fully hackable charging station for electric vehicles. It supports single and 3 phase power input with an all important RCD capable of tripping at 30mA... Oh and it also has an LED strip output if you really want to pimp your ride."



"Throughout the Spring and Summer we’ve been watching as hundreds step into the spotlight to share their projects with the world. Now we’re in the final stretch as these twenty entries all try to claim the grand prize..."

The Definitive Open Solution for EV Charging

Prism is the first commercial charging station that offers full, hassle-free control over the entire charging process. Prism offers a higher quality-to-price ratio than other products currently available on the market. And, most importantly, it is the only device of its kind that benefits from the flexibility of an open architecture.

Universally Compatible

Prism supports charging through a Type 2 socket (commonly referred to as a Mennekes plug) and is therefore compatible with all newer electric vehicles sold in Europe. A version with a Type 1 connector is available for those who need to charge older vehicles. And, if your vehicle has neither a Type 1 nor a Type 2 socket, third party adapters are easy to find. With support for all standard protocols, Prism gives you all the tools you need charge your electric vehicle or to develop new ideas for sustainable mobility.

Extensive Management System

Our goal is to give you full control over the process of charging electric vehicles. Prism includes a user-friendly interface, which you can access through your browser or using a mobile app. It provides access to all of the settings you might need to manage the charging process and monitor related information. It also displays usage data and offers real-time control over charging schedule and power. Prism can communicate with other devices and software using standard protocols such as MQTT and OCPP 1.6, or by means of a simple hub-and-spoke configuration. You can also integrate Prism into your home automation ecosystem.

  • Have an electric vehicle that lacks the ability to set its own

charge limits? Program Prism to stop charging at 75% or whatever fraction of "full" you deem optimal.

  • Need an easy way to reconfigure your charger? Record *knocking

command* sequences to trigger customized behavior. Knock on Prism four times to set a charge limit of 80%, for example, or knock once and revert to 100%. Even if you’re wearing gloves and your hands are full of groceries.

  • Want your vehicle to draw power only if the rest of your household energy

consumption is below a certain threshold? Or to charge only from what you generate through photovoltaics? These are just a few of the ways you can customize Prism.

Available for Developers and End Users

We are offering Prism in four different configurations. Check out Prism or Prism Double if you are looking for a fully-assembled charging station, with an enclosure, that is ready to use right out of the box. If you want to build your own enclosure, you probably want the Prism Core EV Kit. And if you’re a developer, have a look at the Prism Core Starter Kit, which includes a control module – all of the Prism boards assembled inside a custom DIN box – but does not include the industrial contactor, the residual current monitor, an EV charging cable, or an enclosure.

  • For End-Users: Prism and Prism Double are complete solutions, ready to begin charging your electric vehicle – or vehicles – as soon as they arrive. Prism is available either as single-phase charger, capable of up to 7.5 kW of AC power, or as a three-phase charger, capable of up to 22 kW of AC power. Prism Double is single-phase only. Both Prism and Prism Double are available in black or red, and include your choice of a two, five or seven meter cable with either a Type 1 or a Type 2 connector. Prism Double includes two such cables and can charge two vehicles simultaneously.

  • For Developers: The Prism Core Starter Kit and Prism Core EV Kit allow you to experiment with software related to electric mobility. They are designed to communicate with all of the devices involved in energy production and consumption: from photovoltaics (PVs) to the storage system to the vehicle itself. With the Prism Core Starter Kit, you can develop improvements to the charging management process, extend the user interface, or integrate Prism into a home automation setup, to name just a few potential areas of innovation. The Prism Core EV Kit adds a 63 A contactor, an RCD cable, and an EV cable with connector. It is, essentially, a Prism without the enclosure and the internal high current wiring.

Features & Specifications

Prism includes an embedded Linux system, a versatile MCU for realtime processing, flexible networking options, a robust collection of power-management technologies, and an addressable RGB LED strip – all in a compact, high-design enclosure built for safety, durability, and "wall appeal."

Safe, Durable and Compact

Prism is designed for safety. It includes an electronic Residual-Current Device (RCD) that detects current leakages and an I²C bus that can be used in conjunction with one or more temperature sensors to help prevent fires. It accommodates temperatures anywhere from -20° to 55° Celsius (-4° to 131° Farenheit) and satisfies IP54/IK08 physical protection standards.

Weight & DimensionsWeightLengthWidthHeight
Prism Core Starter Kit< 1 kg11 cm7 cm6 cm
Prism Core EV Kit< 8 kg30 cm30 cm30 cm
Prism< 10 kg30 cm30 cm30 cm
Prism Double< 15 kg30 cm30 cm45 cm

Technical Specifications

  • Embedded Linux System: 540 MHz, 128 MB RAM, 32 MB of flash
  • Realtime Processing: STM32 MCU
  • Connectivity: Ethernet, Wi-Fi, and support for OCPP communication protocols
  • Power meter: ATM90E36 with Fourier analysis functions to measure voltage, current, THD, DFT, and mean power
  • Industrial Contactors: Rated to 63 A
  • Current Leakage Sensor: RCM14
  • Integrated Power Supply: 20 W
  • Input Voltage
    • Single-Phase: 110/230 VAC ± 10%
    • Three-Phase: 400 VAC ± 10%
  • Nominal frequency: 50 Hz/60 Hz
  • Metering: Class B - EN50470
  • Overvoltage Protection: CAT III
  • Residual Current Detection: 30 mA AC, 6 mA DC
  • Physical Protection: IP54/IK08
  • Working Temperature: -20° to 55° Celsius (-4° to 131° Farenheit)

Prism Flowchart

Comparison Table

Prism OpenEVSEWallbox CopperEnelion Stilo
DIY kit availableYes Yes No No
Open HardwarePartial * Yes No No
Linux BasedOpenWRT No RasPI CM? Unknown
Customizable SoftwareYes Yes No No
Customizable Front PanelYes Yes By manufacturer By manufacturer
Screw-Free WiringYes No No No
NetworkingWi-Fi, Ethernet Wi-Fi Wi-Fi, Ethernet, Bluetooth Optional (Wi-Fi, Ethernet)
Wi-Fi access pointYes No No No
Safety & Durability
Integrated RCDType B No Optional Optional
ProtectionIP54 None IP54 IP54
OTA updatesYes Manual UnknownUnknown
Contactor rating63 A Variable 35 A 35 A
Integrated cableYes Yes Yes Yes
Dual charging optionYes No No No
Load balancingOpenEnergyMonitor OpenEnergyMonitor Optional (custom) Optional (custom)
Designer enclosureYes No Yes Yes

* - Hardware and firmware are open and documented but sources will not be available at launch

A Note on Certifications

Prism is designed to meet EU regulatory requirements and is CE certified, but it has not been tested for the US market. We suggest that US backers choose the Core Starter Kit. It was designed for 110 V Live-Neutral systems, at up to 32 A, but it should be easy to adapt for 240 V split phase systems. Current can be increased using larger current transformers and contactors.

Support & Documentation

Please visit our page to learn more about the software elements of Prism, to make suggestions, or to let us know about any issues you might encounter.

Manufacturing Plan

We are using a Chinese OEM manufacturer for Prism PCB assembly. Cables, enclosures, plastics and other minor components, such as screws and grommets, are from EU suppliers. We prepare, calibrate, and test each board at our headquarters in Padova, Italy, before assembling them and packing both Prism Core and Prism units for delivery.

Fulfillment & Logistics

Prism ships free worldwide, and all prices include VAT and other regional sales taxes. All European orders will be shipped directly from Cartender in Italy. Crowd Supply will fill all other orders from their facility in the United States. If you have questions about fulfillment, please see the Crowd Supply Guide first, then contact Crowd Supply directly if the Guide does not answer your question.

Risks & Challenges

We have already begun production of the first batch of Prism and Prism Core units. All components and materials have already been shipped to our headquarters and are currently undergoing test and assembly. We see no particular risk in this phase.

Who is Cartender?

The production of electric vehicles continues to expand, bringing with it a range of choices for customers. Many charging related products have appeared on the market, but one is still missing: an open solution for residential and commercial charging. We saw this as an opportunity, back in 2016, so we began working on Prism. We have developed a number of hardware prototypes since then, and our software has steadily improved. Now on our third iteration of Prism, we believe we are ready to enter the market. And, given the open nature of the project, a Crowd Supply campaign feels like the perfect way in which to do so.

At Cartender, we are passionite about products that contribute to sustainable mobility. We have worked in the automotive industry for years and, over that time, have gravitated toward projects that promote energy efficency. We know that electric vehicles are increasingly necessary, and we see that they are increasingly popular. We believe they will be part of our future, and we want to give users more control over that future.



We are passionate about technology, mobility, and efficiency. With this spirit we founded Cartender, a project to develop Hardware and Software solutions to support and accelerate a transition to sustainable mobility.

Alberto Stecca


Cristiano Griletti


Michele Brunelli

Hardware Engineer

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