Open Vehicle Monitoring System

So, one of the things I like about owning a Nissan Leaf is that I have the ability to check on my car’s state of charge remotely, ensuring I know if someone unplugs it, or something goes wrong while charging.

I can also check and see how many miles of estimated range I’ve got, so if I only need enough to get home I don’t have to wait for a full charge before leaving.

The Twizy doesn’t have this facility, but thanks to the Open Vehicles project, it’s possible to add this function as an aftermarket hobbyist extra.

Behold the OVMS!

Support for the Twizy is certainly well behind that for the Tesla Roadster (which is what the project originally started on). However, there’s some great strides going on thanks to hard work from the open source community, and you can now plug your Twizy into the system reasonably easily if you’re geeky enough!

I’m currently sans Twizy, but I’m hoping that my replacement car will be on its way soon and then I’ll start to play.

IN terms of cost, the unit and the necessary cables costs about £100 all-in. On top of that, you need to buy a SIM card that will take care of the data and text messages the system needs to communicate with the outside world. You can then either opt to use SMS only, or to go through the OVMS server (which is free).

Another nice feature is that it adds GPS to your car. Not in terms of road routing, but in terms of location. It makes it easy to find out where your car is (if you forget where you parked it) or if you have the misfortune of having it stolen.


Looks like a good idea-interesting and a cheap tracker device!

It’s also worth mentioning that ZCW is working on supporting this very system too. Imagine what you could do if your car and other aspects of EV driving worked together in harmony?

The first documentation for the Twizy is now available. Read it here:


I’ve now got the OVMS system installed in my Leaf (while I’m waiting for the Twizy to arrive) and all seems to be working. While I can’t see the Twizy-specific stuff, I can tell where my car is!

I also installed a module in my boss Tesla Roadster. It all worked great too, and he can now do remote charging, check SOC etc all from his smartphone.

Anyone interested in a proper review when the Twizy arrives here? It should come this week :slight_smile:

I would be interested in a review of this for sure :slight_smile:

I think we can do something with that. Just waiting for the Twizy to arrive. Then I’ll do some install info and a review :slight_smile:

Just an update, in case anyone is interested.

OVMS is now getting a bit of a make over, thanks to integration with the Open Charge Map.

Essentially, the iOS App (and Android in time) will let you monitor your Twizy’s SOC as well as find out where the nearest charging stations are. :slight_smile: There are a bunch of other neat features on the way too – so get your OVMS module and start having fun! :smiley:


[FONT=Verdana]Here’s one of the current OVMS developments… integration with the [/FONT]OpenChargeMap[FONT=Verdana] Charging Station database which will give us a list of Charging Stations within the range of the car based on current SOC [/FONT]:smiley:

It would be nice it it showed only the points with the connectors a user selects.
Currently without an adaptor not many suit the Twizy. So I would select on 13amp 3 pin (BS1693).
When I get an adaptor for type 2 to 3 pin then I would want to see these as well.

It will… this is just a sample snapshot of the development… for example we will have the ability to select charging locations within range of our EV based on connector type, SOC, speed, route, terrain, etc. All done automatically using the inbuilt GPS and coms with the EV’s CAN bus.

This is all open source so you can develop pretty much anything you can imagine (I’m working on some integration between my EV and my solar PV for example).

Here’s my tutorial at ZCW on installing the OVMS in my Twizy. I hope it makes sense!

Ah, that’s a usefull instruction. Now I can finally move move OVMS module from the box to a neat place. But how to remove the front cover?

Hi Pieter,

The front cover (light cover) simply unclips. Gently pull from the front and it should come away. When replacing, make sure you locate all the locking tabs as it’s easy to forget/miss one! :slight_smile:

Behind this cover too, you’ll find the brake fluid reservoir. Useful to know!

I am also (one day) going to put a J1772 or Mennenkes inlet behind the Renault Logo. But right now, I can’t figure out how to do it without doing huge amounts of work!


I read your tutorial couple of times, I’m not sure I understand where exactly you place the module itself. You explain very well where you put the data cable, the antenas, where does the module go ?

In all honest, it can go anywhere it will fit securely under the dash! Mine is stuck to the inside lower dash panel in the middle. With a little patience you can reach in there when you have the fuse box cover off.

In other words, mine is in the area between the steering wheel and the lower dash moulding.

Understood, thanks for the clarification.

Looks good i’ll be watching this thread with interest :). Its the kind of thing I would have on mine, but first I need a twizy !

It’s a great system. I highly recommend you invest in one when you have a Twizy. Although there is talk of various upgrades in the coming months :slight_smile:

In case you didn’t see my other post on the subject, I wrote a lengthy exposition of collecting and analysing Twizy OVMS trip data recently over at my blog.

The hardware will be available from the ZCW Shop in a couple of weeks. It will be the same price as buying direct but save the hassle (and the CO2) of buying direct. I’m sure Nikki would be happy to help the community with firmware upgrades :slight_smile: