Build your own EV charging solution | Hacker News Reader

Build your own EV charging solution

chargelab.co

52 pointsstonlyb32 comments

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

Cool project!

Since I'm not particularly familiar with that space, I saw that the first picture shows three different amperages that are being sourced. Is it because the amps are being sourced from each current phase in a three phase setup?

That screenshot includes the home power consumption and solar panels.

Most EVs source the same current on all 3 phases most of the charge cycle and switch to a single phase when they are almost full (and charging goes slower).

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/

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

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.

Not to mention the collection of your data. Check out that privacy policy, first thing I read.

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.

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-...

How is the separate metering done?

Presumably the EV charger communicates usage data with the utility and they reconcile that with the main meter before sending the bill.

It sounds like you just have a way of tallying up your EV charging and sending it to the utility. For awhile PG&E has had separate EV plans if you physically install a separate meter, which seems silly.

As it is, our time-of-use plans are hardly any cheaper off-peak vs on-peak. They've made my plans worse and worse over the years.

If it's a retrofit (ie.: the ev charger/nor the meter have the right technology and setup) EV energy pattern consumption is rather unique, and is very easy to understand consumption through energy disaggregation algorithm.

It's a technology already used at utilities companies to understand for instance if a household has electric or gas hobs.

That's too bad. As is, I get the lower EV rates through the whole house, whenever the utility company detects that I'm charging my car. I suspect that utility companies don't like charging less for non-EV power, so can only assume they backed this.

> As is, I get the lower EV rates through the whole house, whenever the utility company detects that I'm charging my car

It wouldn't make much business sense for the utility to lower your rates when you are charging your car. It's usually the other way around: you charge your car when the utility rates are lower. Which utility is this? Also how are they detecting a car charging vs some other large load like an AC or electric stove?

> you charge your car when the utility rates are lower

I'm not sure if it comes from state funding, or profit, but they want to incentivize charging at off peak hours.

https://www.sdge.com/residential/pricing-plans/about-our-pri...

I'm not sure how they detect it, but it's reliable. My naive assumption is that they detect the sustained 7kW increase, in the wee-hours. I haven't attempted to trick it.

Those are time of use rates, so I don't believe it's detecting your car, but just incentivizing you to schedule your charging at the cheapest time.

This is doubly true in California, where almost no utility will sell you power at low rates during peak demand hours.

No, it's absolutely detecting our car. That's what the support told us, and I see the days that I charge on my bill. They're always accurate.

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...

ChargeLab co-founder here!

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

How did you get into this space? I previously would imagine that most EV companies or folks building out their own chargers would have this type of thing figured out, and so I'm probably wrong! Would like to hear more about that.

EV charging is similar to many other infrastructure businesses. The companies that install, own, and operate EV chargers don't build the actual EV charging hardware and software.

If you were to compare it to the petrol industry, Shell builds gas stations, but the less-known Gilbarco Veeder-Root builds the actual gas pumps and POS software.

What's different in EV charging is that almost anywhere can be a refuelling station -- grocery stores, office buildings, condos, apartments, even single-family homes.

With some many use cases, it's impossible to build a comprehensive product to serve every niche. At ChargeLab we focus on the core needs of the industry, like hardware-agnostic device connectivity, device monitoring, reporting, power management, and payments. Then we provide a public API to enable others to build niche-specific solutions on top of our platform: a unique fleet scheduling tool, an integration with existing petrol loyalty programs, or just a custom interface for your apartment building.

Is there anything preventing widespread adoption of Plug and Charge? And could it be implemented in a way that doesn't require registering with every charging company separately?

I have literally 17 different charging apps on my phone. Almost all of them are truly awful clunky garbage, and seem to exist solely to harvest my private information, and to press "Start".

My impression is that car manufacturers have just been slow to roll it out, and that the implementations aren’t that standardized so there’s another layer of adoption by the charging networks that has to happen.

Agreed about the apps. Have you found any that you particularly like? Pretty much all of them are just map > list of chargers > start button. NFC tap or scan a QR code if it’s “fancy”. But I’ve yet to use anything I thought made charging a nice experience…

Ionity and Fastned are the only two I have a positive opinion of. Fastned especially, because they do support Plug and Charge.

We put a QR code on every charger and provide a web app so that users don't have to download another app.

Plug and Charge is exciting, but there's many limitations. Mostly comes down to vehicle manufacturers and charger manufacturers. On both sides, there are many that don't support ISO 15118 yet.

ChargePoint's security concerns about ISO 15118 published a few years ago were also valid (https://www.chargepoint.com/files/15118whitepaper.pdf). A man-in-the-middle attack is possible with the current version of the ISO 15118.

1) When you say hardware agnostic, is that really true? how standardize is the hardware of EV charging ? Do you require the compatible EV to have a specific protocol implemented or do you have some firmware level integration ?

2) how easy is to scale this business in different geo ? I believe you started in Canada and now present in NORAM, what would it take to get to EMEA?

3) You business model is b2b, but would you be interested in going b2c and leverage a network of EV running your OS ? (independently of who's operating it). For instance with a Cross EV charger subscription

1) There's an open protocol called the Open Charge Point Protocol (OCPP). It's been adopted by all of the top hardware manufacturers (ABB, Siemens, Schneider Electric, Eaton, Delta, Phihong, etc.). So long as a charger complies with OCPP, it will work with our cloud.

There are still holdouts that do not use the protocol or make it difficult to access within their firmware, like ChargePoint and Tesla.

Just like any industry, "hardware agnostic" does not mean "any hardware". But our platform does work with 4 out of 5 of the most sold EV charging brands in the world!

More on OCPP here: https://www.chargelab.co/industry-advocacy/ocpp

2) We're focused on North America right now. We have ambitions to serve other markets, but it's really tricky to hop the Atlantic. Language, GDPR, and other things make it tricky to enter new markets. We're also only running on one cloud region now (us-east-1). As we scale we'll naturally run instances on different cloud instances, but haven't done so yet.

3) We would provide the technology to enable this, but might not create it ourselves. Our customers (all the emerging charging networks) will have much stronger opinions on whether they want to create a subscription with each other or not.

Great questions!

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.

> "build your own" implying a simpler installation

What? When did "build your own" imply "simpler"? Cheaper maybe, fun, or custom. Never have I associated "simpler" with "build your own".

Designs targeting DIY are often simplified for easier build and maintenance by the individual.

Simpler than building out Chargepoint or Electrify America for instance. If you read their materials, you’ll see you can go pretty far with what they have. Let us know when you exceed what they have, that will be really interesting to read about! It’s overkill for most people though.

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