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Welcome to the Wiki Site. Everyone registered at the forum can login here with the same username and password and can make changes.

Before you begin:

Please take the time to read. 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 projects consists of a core development project around an open source inverter, a power stage, taking the DC current provided from a battery and converting it to a controlled signal to drive AC and PMSM motors.

The project has also spawned additional projects that take existing OEM Power Stages/Inverters from cars, which having been made in bulk and are now cheaply and readily available, and provides a means of upcycling and taking control of them so they can be used in conversion projects.

There are also additional projects and discussions in the forums for components beyond the power stage, such as Battery Management Systems, Motors, Batteries, etc.

Combined these projects and discussions and the community effort on this wiki and on the forums aim to make converting existing internal combustion engine (ICE) vehicles, a cheap and easy proposition for individuals, and companies, looking to specialise in converting ICE vehicles.

The open inverter project consists of three main aspects:

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

Inverter variants available:

Open Inverter (Core Project)

Open Inverter Related Projects / Control Boards

This is the kit provided to build your own power section,

meaning sourcing and constructing your own IGBTs and

other components.

This is the kit/boards for use with existing power sections,

meaning inverters sourced from OEM parts taken

from existing cars, etc. and utilising the components

within them.

Open Inverter Hardware
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.

Lexus GS450h Inverter / VCU:

the GS450h provides a gearbox (where the motors are located)

combined with the original inverter, this board looks to control

the inverter and the gearbox itself to 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 VCM:

this vehicle control board plugs into the Nissan Leaf inverter externally

and controls it via CAN

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

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

Further Components

Once you have the inverter, you will need additional components for your EV conversion:

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


Open Inverter CAN std.

Glossary of Terms


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

OEM Parts