A disassembled EV charging station, and a working one

Modernizing An Outdated Electric Vehicle Charging Station

June 12, 2022 by Robin Kearey 15 Comments

One of the drawbacks of being an early adopter is that you might end up investing in equipment that becomes obsolete rather quickly. Although it’s clear that electric vehicles are here to stay, those who bought a charging station for their EV a few years ago may find it slow and incompatible with modern cars or billing networks, necessitating an upgrade to one of the latest models.

If you don’t mind tinkering, these older chargers can provide an excellent base to construct your own state-of-the-art charging station, as [James] over at Diary-of-a-Geek did. He bought a Chargepoint CT2000 series charger and installed a brand-new charging unit inside based on OpenEVSE components. The CT2000 is an older model that’s no longer manufactured, and although it can still connect to Chargepoint’s network, a subscription renewal would cost several thousand dollars. [James] was not willing to make that investment for a unit that he was going to install at home anyway, so he decided to buy replacement parts from OpenEVSE, a supplier of open-source EV charging stations and components.

An OpenEVSE controller mounted on a bracket — The OpenEVSE charging controller sitting on the ChargePoint bracket

The insides of a charging station are actually pretty simple, since the real battery charger is inside the car: the station just contains a beefy contactor to switch the AC current on or off, along with some circuitry to measure the current flowing and an interface to connect to a payment network of some sort. The first step therefore was to hook up the contactor and current transformer to the OpenEVSE controller. This was easy since the new part was way smaller than the original and could simply be mounted onto an existing bracket.

The second step was to provide the user interface and network connections. [James] removed the displays and wireless systems from the head unit and cut a large hole into the front to provide space for new LCD displays. A set of status LEDs plus WiFi connections completed the system, which now looks just as professional as the original. Tests showed that the LCDs were hard to read in bright sunlight, so [James] replaced them with OLED displays, but otherwise the renovated charging station worked perfectly.

Of course, working with high voltages and large currents requires the proper skills and tools, which [James] clearly has available; he also stresses the importance of including a ground-fault circuit interruptor in any equipment placed outdoors. He isn’t the only one to make his own charging station either. If you’re confused by the many types of EV charging connectors, have a look at our recent article describing all those different plugs and sockets. Thanks for the tip, [Kevin]!

EV Charging Connectors Come In Many Shapes And Sizes

April 28, 2022 by Lewin Day 69 Comments

Electric vehicles are now commonplace on our roads, and charging infrastructure is being built out across the world to serve them. It’s the electric equivalent of the gas station, and soon enough, they’re going to be everywhere.

However, it raises an interesting problem. Gas pumps simply pour a liquid into a hole, and have been largely standardized for quite some time. That’s not quite the case in the world of EV chargers, so let’s dive in and check out the current state of play.

AC, DC, Fast, or Slow?

Since becoming more mainstream over the past decade or so, EV technology has undergone rapid development. With most EVs still somewhat limited in range, automakers have developed ever-faster charging vehicles over the years to improve practicality. This has come through improvements to batteries, controller hardware, and software. Charging tech has evolved to the point where the latest EVs can now add hundreds of miles of range in under 20 minutes.

However, charging EVs at this pace requires huge amounts of power. Thus, automakers and industry groups have worked to develop new charging standards that can deliver high current to top vehicle batteries off as quickly as possible.

As a guide, a typical home outlet in the US can deliver 1.8 kW of power. It would take an excruciating 48 hours or more to charge a modern EV from a home socket like this.

In contrast, modern EV charge ports can carry anywhere from 2 kW up to 350 kW in some cases, and require highly specialized connectors to do so. Various standards have come about over the years as automakers look to pump more electricity into a vehicle at greater speed. Let’s take a look at the most common options out in the wild today. Continue reading “EV Charging Connectors Come In Many Shapes And Sizes” →

DIY Arduino Based EV Charger Saves Money, Looks Pro

April 28, 2022 by Ryan Flowers 63 Comments

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.

Continue reading “DIY Arduino Based EV Charger Saves Money, Looks Pro” →

Bad Boy Charger

November 11, 2006 by Will O'Brien 21 Comments

This is one of those hacks that scares me a little bit. The ‘Bad Boy’ charger was created by Tom Martin to charge EV battery packs. [Pictured is one built by Mike Chancy] You can find the schematic under austinev’s tech files. This thing is a bare minimum power supply – it’ll deliver loads of essentially unregulated power into a set of batteries. If you check out the circuit, you’ll see just how scary this thing really is, but according to its users, it works.