Building my own EVSE


While I’m waiting for my Tesla Model S I also bought a new house. In December 6th 2011 I received the keys and ever since I’ve been working on the electrical infrastructure to prepare everything for the 3-phase charging station (EVSE) which should go into the garage.

I modified my fistribution panel to have a dedicated 3x32A connection to my garage where I can install my EVSE. The purpose is not only to charge the future Model S, but also the Roadster of my colleague and other EV’s which might visit me.

But then, which EVSE do you buy? I’ve been looking around and a EVSE capable of 3x32A costs about EUR 2000,00! It’s nothing more then a CFGI, a fuse and a controller, so I figured that could be done for less.

After some searching I found the Open EVSE project. I was sold right away! What’s cooler then building your own EVSE with Open Source software!?

I ordered the Open EVSE kit with the Advanced Power Supply and got it last week. Right now I’m waiting for my 63A relais (I like it beefy) and some other components like the Type 2 socket for in the outer-wall of my garage.



The Model S won’t fit in the garage, so I’m going to install the Type 2 socket in the outer-wall of the garage. All the EVSE components can be inside, that will make it very clean. Just a Type 2 socket where you plug in your EV and it starts charging! Couldn’t be easier.







To my garage I’m running a 5G6 cable. That’s five wires of 6mm2 each. This cable will be capable of doing 3x32A which should recharge the 85kWh battery in a little bit over 4 hours.

My main fuses are 40A, so when I’m charging with 3x32A I can’t turn on my oven or use my electrical cooking. Open EVSE however supports dynamically changing the current.

In my distribution panel I have a kWh meter with a M-Bus exit over which I can read out the current going through my main fuses. I’ve made a nice web page where I display this information, but the main goal is to have the EVSE read out this data and adjust the current based on what other appliances in my house are using.

This way I’ll never blow my main fuses and I’ll still be able to use 32A at the EVSE when available. Something like my little smart grid!

As I’m still waiting for a couple of components I’m not going to post anything yet about which I’m using. I promise, I’ll add a Wiki on the Open EVSE page about how I build my 3-phase EVSE with Open EVSE!

That’s it for now, keep tuned for more information!

Now it’s back to waiting… Not only for the components, but also for the Model S!

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Wido den Hollander

I am the CTO at PCextreme B.V. and i will keep this blog just to post some interesting information about my daily work on Linux (and other) systems.