Electric vehicles (EVs) are something of a hot topic, and most of the hacks we’ve featured regarding them center on conversions from Internal Combustion to Electric. These are all fine, and we hope to see plenty more of them in the future. There’s another aspect that doesn’t get covered as often: How to charge electric vehicles- especially commercially produced EV’s rather than the DIY kind. This is the kind of project that [fotherby] has taken on: A 7.2 kW EV charger for his Kia.
Faced with spending £900 (about $1100 USD) for a commercial unit installed by a qualified electrician, [fotherby] decided to do some research. The project wasn’t outside his scope, and he gave himself a head start by finding a commercial enclosure and cable that was originally just a showroom unit with no innards.
An Arduino Pro Mini provides the brains for the charger, and the source code and all the needed information to build your own like charger is on GitHub. What’s outstanding about the guide though is the deep dive into how these chargers work, and how straightforward they really are without being simplistic.
Dealing with mains power and the installation of such a serious piece of kit means that there are inherent risks for the DIYer, and [fotherby] addresses these admirably by including a ground fault detection circuit. The result is that if there is a ground fault of any kind, it will shut down the entire circuit at speeds and levels that are below the threshold that can harm humans. [fotherby] backs this up by testing the circuit thoroughly and documenting the results, showing that the charger meets commercial standards. Still, this isn’t a first-time project for the EV enthusiast, so we feel compelled to say “Don’t Try This At Home” even though that’s exactly what’s on display.
In the end, several hundred quid were saved, and the DIY charger does the job just as well as the commercial unit. A great hack indeed! And while these aren’t common, we did cover another Open Source EV charger about a year ago that you might like to check out as well.