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Welcome to the open inverter wiki, please take your time to read!

The open inverter community is growing and moving quickly.

Stay up-to-date with the latest developments and findings, please check out the forums

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Before you begin:

Please take the time to read.

Developers of various projects are often bombarded with private messages and emails. Managing these emails and question is a extremely large undertaking. Please read, and take the time to understand the information available here and across the web if you don't understand a topic. Developers are not your personal support team!

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The information provided on this wiki and the support forums is intended as information only. The Open Inverter project and it's contributors take no responsibility for how you use the information contained within these pages, nor any liability for injuries, or death, that may result from your actions.

You undertake your project at your own risk.


The open inverter project originates from Johannes Hübner designing/building his own open source AC motor controller, dubbed the "open inverter"

With the rising popularity/availability of hybrid and electric vehicles, there is a growing supply of high quality and relatively inexpensive parts from auto-wreckers.

The main goal of the open inverter community is to reverse engineer many of these components for use in a variety of projects such as:

  • EV conversion
  • Energy storage
  • Power generation
  • Charging infrastructure
  • etc.

Open inverter projects now span over many different areas surrounding PEV, HEV, and PHEV components, such as:

  • Motor Controllers
  • 1-3 phase power converters
  • DC/DC converters
  • buck/boost converters
  • Battery Management Systems (BMS)
  • Vehicle integration
  • etc.

As a results, there is a growing collection of open source software and hardware designed for the never ending list of OEM parts.

There's a variety of methods of repurposing these OEM components. Methods here are generally chosen with future proofing in mind , reducing chances of firmware or software updates from the manufacture "bricking" or blocking the open source control efforts.

such efforts include:

Resulting in many bespoke boards running the main open inverter software or other open/semi-open source code designed to ether replace OEM motherboards or VCUs.

This has lead to a large collection of different boards and software, many with redundant features. To unify many of these development projects, the community at large is focused on making a set of standard VCUs and replacement control boards which handle the ever growing list of OEM components.

Many of the VCU and replacement boards consist of these 3 main parts:

Hardware Firmware Web Interface
The design and development of the control hardware based around an STM32F103 chip. This provides the control signals to the power stage and on to the attached components. The development of the code that goes on the STM32F103 chips and determines, amongst other things what signals are sent to the power stage and the attached components. Using an ESP8266 chip, the development of a simple web based interface to adjust the parameters on the firmware chip and to display values returned from the chip, for example motor speed (RPM).

Getting Started

It is recommend reading the Glossary of Terms before continuing further.

EV conversions:

A few main parts are needed for an EV conversion, such as:

Existing information on these items can be found on the EV Conversion Parts page.

OEM Parts:

A variety of OEM parts members of the community have reversed engineered for custom use cases:


mechanical design database

Designs for:

  • adapter plates
  • motor couplers
  • drive shaft flanges
  • battery mounts
  • etc.

Open Inverter (Core Project/s)

Open Inverter Related Projects (Control Boards/VCUs)

core universal hardware and software components
ZombieVerter VCU Tesla Small Drive and Large Drive Units:

commonly there is a large drive unit and small drive unit available. These combine the inverter and motor into a single package. The control boards for these replace the existing control board within them.

Open Inverter Hardware
Lexus GS450h Drivetrain:

The GS450h contains a gearbox (where the motors are located). Using the ZombieVerter VCU, the inverter and the gearbox itself provide a powerful set up suitable for rear wheel drive set ups, replacing the existing longitudinally mounted gearbox.

Prius Generation 3 Inverter:

a cheap available inverter from the popular Prius hybrid, this

board goes inside that inverter and allows you to control the features of it.

Open Inverter Software
Auris/Yaris Inverter:

similar to the Prius board, there's subtle differences between them and therefore the need for a separate board.

Nissan Leaf Gen2 Board

replaces the nissan OEM logic board with a rev 3 openiverter main board

Ford ranger ev board

openinverter kit for the ford ranger ev

All Control Boards / OEM Inverters
CAN communication

Common across boards is the ability to communicate with a CAN Bus, which is a 'control area network' or a technical way of saying how various components, sensors, controls, etc communicate with one another within the car. Read more about CAN Communication

There is also a project to standardise the messages across the various control boards, read more


The openinverter firmware uses a set of about 70 parameters to adapt it to different inverter power stages, motors and position feedback systems. Also it lets you calibrate the throttle pedal, change regenerative braking settings and so on.

Parameter definitions can be found here: Parameters

Working parameter sets can be found in the openinverter parameter database

Use inverter as a battery Charger

Both the open inverter and some OEM inverters can be used as a battery charger, further saving on component costs. You can read more about how the open inverter and the theory of charging here.

Open Inverter CAN std.


Different countries have different legislation, if you want you car to certified for the road in your country please take the time to review this section.

Conversion Projects