from Hacker News

Build your own EV charging solution

by stonlyb on 8/11/22, 9:22 PM with 32 comments

• by Dries007 on 8/11/22, 11:04 PM

  Funny, I've just started working on adding OCPP support to the SmartEVSE v3 platform.

  If you want a capable DIY solution, I recommend the SmartEVSE (v3) platform. The hardware is quite capable (ESP32 based, support for switching between 1 & 3 phase charging). The software requires some more work to fully utilize the hardware, but is open source.

  No cloud APIs required :)

  Code & schematics: https://github.com/SmartEVSE/SmartEVSE-3

• by bacon_waffle on 8/11/22, 10:09 PM

  I've had an OpenEVSE[1] for a couple years now, it works great and is quite hackable. Interface is ESP32 based, newer firmware versions provide MQTT-based control and feedback. Historically it used WiFi but just last night I made a PR for to improve Ethernet support. There are a few rough edges in terms of "build your own", but if you're interested in this stuff it's a great starting point and hardware platform.

  [1] https://openevse.com/

• by adev_ on 8/12/22, 1:26 AM

  That is mainly an API for professional usage and not so much to do with making your own EV charging.

  If some of you are interested by some DIY smart EV charger for home usage. I did one for myself and put the design on github some years ago:

  https://github.com/adevress/open-ev-station

  - Designed for 11KW of power

  - Designed for European Grid power (can be adapted)

  - Support three phase power

  - Support remote control over wifi

  - Measure Energy consumption

  - Time programmable

  - Does not requires any programming: It use a shelly 3EM

  - Simple, Stupid and safe design

• by josephcsible on 8/11/22, 10:04 PM

  If I were to build my own smart EV charger, the entire point of doing so would be to not depend on any third parties for it to work.

• by Glawen on 8/12/22, 7:53 AM

  I've been on the other side, that is implementing the charging algorithm in the vehicle, it was very difficult to have a consistent behaviour over the many EV charger.

  As I understand, this solution is for the backend, connecting the EV charging station with the internet, but it is not used to connect to the EV.

  Many of our clients thought they just needed to buy/install such a solution to have a fleet of smart charging vehicles, because that is a crowded space and that is what the vendor sold. The issue was the interface EV <=> EVSE as the protocol used for charging was not incorporating smart charging feature (newer protocol was being written at that time). We had to hack the protocol to implement some features.

• by danans on 8/12/22, 1:31 AM

  Neat project. EV charging would get even more interesting if more utilities and commissions would allow EV submetering. California's utility regulator just authorized this a few days ago [1], after many years of deliberation.

  Sub-metering lets an EV charger be metered separately from a house, theoretically allowing it to take advantage of lower EV rates during more restricted times.

  1. https://www.utilitydive.com/news/california-puc-ev-electric-...

• by kkfx on 8/12/22, 3:45 PM

  The real EV charging issue in general for owners is a way to talk to a p.v. plant to try maximizing charging from Sun. Domestic solar systems with lithium (or other tech) storage do that by default, with proprietary tools, cars so far do not.

  It's a pity not much for mere EV charging but for EV usage at home in the broad sense: IF we will arrive to an open API all vendors agree we can use expensive batteries not only for the car but also to power the home in case of outages reducing a bit they obscene cost compared to their life expectancy...

• by z-cam on 8/11/22, 10:11 PM

  ChargeLab co-founder here!

  Let me know if you have any questions about our vision for open EV charging infrastructure.

• by natch on 8/11/22, 10:10 PM

  Since the title is "build your own" implying a simpler installation, I much prefer the comparably reasonably priced offerings from Splitvolt.

  Satisfied customer, no other connection to the company. They also offer different plug sizes right on their website, for those that have less common outlet sizes:

  https://www.splitvolt.com/product-category/ev-chargers/

  Obviously Chargelab seems to be offering more in terms of having an API and programmability, but this is quite a large jump up from the usual solution of just sticking the charge cable that (possibly) came with the car into the wall. Splitvolt is nice as a solution in the middle in between these two extremes.