Modernizing An Outdated Electric Vehicle Charging Station

A disassembled EV charging station, and a working one

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]!

15 thoughts on “Modernizing An Outdated Electric Vehicle Charging Station

  1. I’m going to go check it out, but I am thinking an insulator or double the height of those standoffs are needed if that PCB is mains voltage. Maybe thei insulator is pre attached to the PCB. Here is hoping.

  2. When building something like this, please make sure you get a good quality Class B GFCI.

    Class B is essential since the batteries of the car are DC. A fault in the car could put a DC voltage on your power net, which will not be detected by normal GFCI’s. Even worse, it will saturate the coil in those GFCI’s, preventing them from triggering on any fault, AC or DC.

    Modern charging stations will have a GFCI that protects against this, but that’s always the case in older ones.
    Same goes for solar panels btw.

      1. I’m sorry but no, it really doesn’t.

        It is true that the OpenEVSE has some detection for fault currents. But the components that do this are NOT fail-save, only checked during bootup of the charging station and can even be disabled in firmware. It requires the software to actively monitor, so if a bug causes part of the software to hang or function unexpectedly, your protection is gone. There is no inherent safety in this design.

        And even if there was, the ‘GFCI’-wannabe in the OpenEVSE cannot even detect the 6mA fault currents that should trigger the GFCI in most places (USA being one of the exceptions). Also, it is completely unable to detect DC currents and indeed does saturate in case of a DC fault current. Doesn’t do any arc detection, etc. etc.

        If you want to install this device in Europe, multiple additional safety devices have to be fitted in front of it, and with good reason. DC current leakage is a common failure mode for EV’s. the OpenEVSE is not equipped, at all, to counteract this. The result being that not just the OpenEVSE is unsafe, but it will let the DC current on your power net, making any classic GFCI in your home inoperable.

          1. Indeed. I’m sorry, I seem to have mixed up some of the terminology. It’s Type B. Class B is used for the same where I live, but seems to have a different meaning in some parts of the world.

            GFCI’s are specified for types of current they trip on. Type A or even worse, AC, only trip on (certain kinds of) AC currents and can even be disabled if a DC current is introduced.


  3. I feel as though I’m missing pieces of a puzzle I never knew existed. Why would anybody pay subscription fees of “several thousand dollars” over and above their electricity bill for charging a car at home? Is the network connection necessary to allow the charger to do its primary job? If so, why?

    1. It’s required if you want the charger to be part of the network, so that the public can use your charger and so you can get money for those people’s electricity consumption.
      And yes, the original EVSE may have required a successful connection to the network to work. Unless there’s a “free when disconnected” mode, the charger will stay locked until a successful authorization is accomplished.

      1. Thanks – it never occurred to me that personal chargers would be used by other people. I guess it makes sense, but now I’m trying to figure out the logistics of that for an average neighbourhood.

        1. It’s honestly pretty stupid. The costs of metering and preventing access are much greater than the costs of simply allowing charging in most cases, or charging based on a monthly subscription or similar. We see this for on-street charging in the US, where (a) the light poles next to the charging spots are charged to the municipality are *not* metered, instead charged on a calculated basis by # of lights, expected power draw, hours of daylight, etc, but (b) the utility insists on an expensive full-fledged meter on every light pole if you wanted to put a charging outlet there.

          My town also contracted with chargepoint for the municipal parking lots. Yes, they could have just had the town electricians install outlets and be done with it, since (at the moment at least) charging is free. But if you contract with a chargepoing-authorized provider, you can buy a maintenance contract for a $$/year that will take care of any/all ongoing maintenance for that charger (and sometimes the Town electricians don’t feel comfortable with “EV stuff”).

          I still think this is pretty much throwing money away, but bean counters really like annual maintenance contracts. Even when that required basically throwing all of the chargepoint chargers away and buying new ones when the local telco turned off 2G cell service in the area (the older chargers had 2G data networks).

          I did (at least) ensure that in my state when we added EV requirements to the building code, what is mandated are *outlet* not *chargers*. Chargepoint actually strongly lobbied for the requirement to be *chargers* — so they can get those sweet annual subscriptions for network-connected home chargers when for personal use an outlet works just fine. So there’s regulatory capture involved here too.

          1. Those “subscription” services are usually ocpp backoffices. It’s an open protocol, the most well-known open source implementation is called Steve. If the charger is really yours to keep you should be able to point it to your own server if you wish.

  4. As with anything dealing with high voltages, if you don’t have actual experience dealing with high voltages, PLEASE PLEASE PLEASE consult a licensed electrician for projects like this. This is not something someone should lose their home or their life over.

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