Creating a low-cost EV charging station with Arduino
Comments
gorkish
Moto7451
In case you don't watch Technology Connections...
1. You probably should, Alec is great. 2. Here's a longer broader video about what goes on in an EVSE: https://www.youtube.com/watch?v=RMxB7zA-e4Y&t=1429s
There are too many comments to go sling context left and right, but generally an EVSE is a controller board (what this is implementing), a contactor (this board uses relays), and a GFCI (in North American parlance), which his RCBO provides along with being a current limiting circuit breaker.
Contactors are generally better for these use cases for reliability and current handling reasons but it wouldn't surprise me if SCRs and Relays are in use in low cost 16A EVSEs on Amazon.
cduzz
I've got one of those cheapo 16a chargers from amazon. It's been outside for 3 years running now and still works as well as it did when I installed it. I'm not 100% comfortable with using a nema 6-20 instead of hard-wiring the connection, but it was cheap and easy to get vs pulling some big new service.
I'm kinda puzzled about the system, though -- an EVSE is theoretically about as complex as a smart extension cable, but ... it stays warm even just sitting there not charging and gets to be 20 degrees F warmer than ambient when charging, which seems wrong for "just a relay"
Moto7451
This is how I charge also. I’m going to eventually have a hard wired EVSE mostly for solar timing but I usually am fine at 12-16A on a NEMA 6-20 or 5-20. My $120 unit off Amazon is more reliable than the $1200 Porsche charger I also have (and that is while ignoring the open and unresolved recall for undersized wire used on the plug tail).
My guess is warmth on the unit is a dumb inefficient DC transformer for the controller. There is an Energy Star spec for low standby energy use that most of these inexpensive ones don’t hit.
resource_waste
Ever since he was incorrect about his dishwasher video, I havent decided to spend 45 minutes watching this youtuber.
mtlmtlmtlmtl
How was he incorrect? I've been doing what he suggested ever since, it's worked perfectly(much better than tablets) and I've saved a bit of money not buying those ridiculously overpriced tablets.
magicalhippo
Interestingly I tried it as well, and the result was much worse than tablets.
Shortly after a test of washing machine tablets and powders came out[1], and none of the powders available there came out good in regards to naughty chemicals, while the tablets we had been using had none of those (Yes Platinum all-in-one).
They also came out better in regards to washing quality, so we've since changed back.
[1]: https://www.forbrukerradet.no/tester/vaskemiddel-til-oppvask...
mtlmtlmtlmtl
It's a shame they don't describe their methodology in detail. Makes the results hard to interpret. Specifically whether they add powder to the outside of the chamber. That was the whole point of the video, really.
For me, the results were unambiguous. With tablets I got a bunch of "water spots" that weren't solved by doing any of the typical advice like refilling dishwasher salt and rinse aid or cleaning the machine. The water here isn't particularly hard either. The machine also struggled with certain things like eggs. Pretty sure now that the spots were just from excess detergent, because it stopped happening once I tried the Technology Connections way. It also did a much better job with stains that the tablets struggled with.
magicalhippo
For us the results were also unambiguous. The powder was just plain worse, and even with the extra fluid for shine our glasses came out worse. We did follow his advice of adding some powder directly in the machine.
Increasing washing temperature did help some but not enough. After a week my SO had had enough.
Perhaps it's related to the machine and water quality. We have very good and soft water (no salt needed), with very little chemicals. Perhaps another machine and/or different water quality can explain your different experience.
mtlmtlmtlmtl
Yeah, I'm not questioning your results. Probably some variation related to the machine, water quality/temperature etc. Which is why I wish forbrukerrådet was more transparent about their methodology. Lot of possible confounders they just don't mention. Which machine(s) did they use? Did they use rinse aid? Salt? Which program? How hard is their water and how hot was it, or did they vary these parameters? How full was the machine? Etc.
My machine is pretty old. Old enough that it has no electronics, just one of those mechanical dials that slowly turns back to "zero" during the cycle. There are no programs really, just the ability to set the dial to various subsets of the full cycle.
It wouldn't surprise me if more modern machines are designed more with tablets in mind than powder. Seeing as it's now the most popular product.
magicalhippo
> It wouldn't surprise me if more modern machines are designed more with tablets in mind than powder.
Yeah in comparison ours is a high-end Bosch model that's just a few years old. It has sensors which supposedly detect how dirty the water is and whatnot.
Would be interesting to do a comparison.
For us the main kicker was less of the troubling chemicals. We could have lived with the reduction in washing power had those metrics been inverted.
gattilorenz
According to the website you posted, the First Price powder has less "naughty chemicals" than the tablets you use (but with less cleaning power).
magicalhippo
Only color, which is the least naughy of the ones they checked for AFAIK. And as you note, having it clean is kinda the point of it all.
belval
He's one of those youtubers (everyone seems to have one) that I just don't like, everyone on HN always says his videos are good/educational, but to me he just comes off as confidently incorrect and on the few videos where I am more knowledgeable than the average person his assertions are often wrong which makes me doubtful of his other content.
To anyone reading this who likes his content, I'm happy for you, I guess I just don't get it.
kibwen
His videos are interesting, and he's got an admirable attitude for doing experimentation and research.
But he's not a subject matter expert on any of these things, and it shows. He's more like an independent reporter and/or journalist. Other channels on technical topics often hire experts to check them to make sure they're not making any obvious mistakes, and his videos would benefit from the same treatment.
gattilorenz
To both of you: care to elaborate on which videos and inaccuracies you found?
burnerthrow008
I'm sure everyone will have their own, but some examples off the top of my head:
* In the video about EVs not illuminating the brake light when regen braking, he confidently assumes that the problem is with all EVs, not just the particular brand of EV he drives.
* Not knowing that inverter microwaves exist, and confidently asserting that you can hear every microwave cycle on and off.
* (Over a series of videos) Letting his hatred for Tesla color his videos about EV charging.
For the last bullet: He went on and on about how every other brand uses CSS (with no acknowledgement that more than half of EVs in the US were, and still are to this day, made by Tesla). He ranted that CCS was obviously superior, argued that Tesla was trying to lock in their customers (despite EVgo and a couple others already offering Tesla plugs).
After the industry switched to the "inferior non standard", he started parroting the lines "well Tesla is just CCS anyway" and this is "Good For Bitcoin^H^H^H EVs".
It's too bad because there was actually a lot of good info in his EV charging videos. They're just so heavily slanted that I can't recommend them to anyone.
gattilorenz
Thanks for sharing!
I don’t think the first point is fair tho. If this [1] is the video, at 1:27 he talks about two specific manufacturers. The point of the video was that regulations are outdated so different manufacturers can implement stuff differently, not that “everyone does it wrong”. Around the 13 minutes mark he speaks about GM doing the right thing.
kibwen
I don't have the exact video on hand, but in my case it was a video discussing the performance characteristics of LEDs (which is a regular topic of his), and while it was clear he had done a fair bit of research on the subject, his conclusions were based on a very narrow reading of the resources (which were intended for a technical audience and assumed a certain level of technical background), which belied the confident forcefulness of his conclusions. Other channels (e.g. Veritasium, Numberphile) delegate the heavy lifting of explaining details to professionals by including interview segments, and in this case he would have benefited from letting an engineer explain the topic, which might have tempered his ultimate assertions. It's only a small thing, but it behooves me to consider the Gell-Mann amnesia effect.
zug_zug
Just want to throw this out there -- if you see something like this and you just repeat "I heard this is dangerous don't do" -- you're not really adding any signal to the discussion, you're just repeating nth degree beliefs [some happen to be true, many happen to be false].
Better to comment if you have electrical expertise and can articulate a specific risk. Or perhaps maybe a sincere question toward the actual experts (guarantee there are plenty on this forum) about what the failure modes are (e.g. could this overload if it gets wet and the arduino malfunctions?).
VBprogrammer
Hear hear! The catastrophizing in some of the comments is a bit much.
However, there are plenty of gotchas in installing a EV charger, even a commercial off the shelf one. The regulations are generally pretty tight and are intended to protect from fairly unlikely scenarios. Getting earthing arrangement right etc.
turtlebits
Installing an EV charger involves plugging it in. There aren't any gotchas and only requires a NEMA 14-50 receptacle be installed by an electrician and usually requires a permit.
hi-v-rocknroll
While someone might be able to execute this safely, the risks and intensive processes and need for additional resources fall totally on you to do so properly compared to say a Tesla, Siemens, or ABB. Should anything happen, you will be blamed in practice no matter if you made something wonderful that even a megacorp could sell. Furthermore, many municipalities require permits for these installations and would be unlikely to sign-off on something homebuilt regardless of careful craftsmanship. While I applaud the spirit and effort, it's almost like putting together your own solar, grid-tied automatic transfer switch: sure you could satisfy your own requirements, but the external world is unlikely to certify your work because of insurance and liability reasons no matter how much care and consideration you put into the design, fabrication, installation, and maintenance of it.
Arduino DIY all day, every day... except for fire/life-safety critical systems like elevators, AEDs, automotive airbags or ABS brakes, car chargers, or large HVAC installations.
PS: I sympathize that the world hates almost everything fun or cool.
gorkish
I hear you; however I would counter that what most people want to tinker with is not actually the life-and-safety-critical bits of the system. There are really only a few things that you can meaningfully do with an EVSE anyway: 1) Enable/disable charging 2) Change the current limit 3) Monitor the power draw and 4) Monitor the vehicle state.
Commercial systems don't provide this (at least not without use of their proprietary and/or expensive hardware and software). There's nothing that says that you cannot design and build "fire/life-safety critical systems" that have open designs and open interfaces. Attention should be directed to these efforts.
All of the doomsaying in the comments here is ridiculously unproductive.
fy20
In the same vein, many smart meters coming onto the market have a P1 port [0], which is an open interface to read metering and pricing data.
It's designed to be safely used as an interface by third party hardware, and physically operates over a RJ12 connector (phone jack) with 5V. There are even DIY projects, powered by ESP boards, to interface with it - and electricity companies are ok with that, as it's designed for this use case.
gorkish
That's actually really great! More of this!
hi-v-rocknroll
Yes, yes. Control, DIY, tinkering, and data.
> All of the doomsaying in the comments here is ridiculously unproductive.
Not really. It might not be so much doom as practicality and legality. Reality is reality.
> All safety features required by SAE J1772, UL and NEC are standard.
(from the website)
Is it "UL Listed"? No. That's the end of it. There is no getting around that neither my city will permit this nor my electrician will install it no matter how much I protest that it's unfair. Sure, I could use it temporarily (not installed) or install it illegally without a permit but on sale of such a property, I would have to remove it to avoid it being discovered during an inspection.
If the important components and/or assembled kits passed Underwriters Laboratories' official tests and processes for listing, then my municipality wouldn't object and would take this seriously.
gorkish
I'm not advocating for the system in the linked article; it is a hobby project, but not yet a viable platform that should be used unattended or built buy unqualified hobbyists. I would add that I support the author's right to build it and distribute the designs regardless.
OpenEVSE v4 hardware (which I did advocate elsewhere) is UL listed and more closely matches with the goals of an open and accessible platform with a safe and tested design for those who wish to tinker with monitoring or software systems integrations.
Please stop being such a stick in the mud; its a boring way to live. "Reality is reality", bah.
fragmede
> on sale of such a property, I would have to remove it to avoid it being discovered during an inspection.
how often are you buying and selling houses‽
ceejayoz
An insurance agent somewhere just had an involuntary twitch they can’t immediately explain.
dylan604
Some lawyer also got a twitch, and started updating their addendums/attachments/riders to exclude this from coverage. (I'd be shocked if there isn't already some sort of exclusion to DIY electrical issues)
Scoundreller
As an insurer (if I was an insurer), I hate it when people use something not created by a big monied corporation that we could subrogate claims to.
brk
People here seem to be confusing the functions the charger handles vs. the functions the BMS in the car handles.
This is no less safe than any other DIY installed EV charger.
newsclues
Reliable and safe should be the priorities for ev charging not low cost
brk
As the post explains, the Reliable and Safe bit are really handled by the car, not the charger. This is a neat project, but it is also another example of an Arduino being a bit overkill for what is going on here.
GuB-42
Also note that he installed a "RCBO", whuch stands for "Residual-current circuit breaker with overcurrent protection". It is a breaker that combines the overcurrent protection with what is called "GFCI" in the US. It offers pretty good protection on the mains side, it is also not that cheap, and a little bit overkill.
As you said, the car side is dealt with by the car itself. There are some minor issues (read the YouTube comments, people on YouTube love to comment about safety, justified or not!) but overall quite reasonable from a safety perspective.
This is a slow charger and that car is not that different from a regular appliance from the charger point of view.
1970-01-01
Safety is the electrician's duty. Local electric codes, ampacity charts, properly doing load calculations, pulling permits, etc. will all fall on the electrician's shoulders.
brk
Yes, but the "electrician" can also be an individual homeowner. I've done my own electrical work at times, including permitted and inspected work. One of my last projects was wiring a 50A 240A subpanel, on a dock, over saltwater. 105' of wire underground, appropriate GFCI's, etc. Not exactly a simple job, but all the requirements are clearly documented if you take the time to read through things. There is no reason a smart/competent person can't install an EV charger, or create an interface to the power delivery with appropriate components.
lnsru
The bad thing is that short sighted and mentally limited persons still think about themselves as brilliant geniuses. That’s why you have complex electrician’s certification with theoretical and practical parts in Germany to sort out these brilliant geniuses.
Edit: my buddy is ex-googler. IQ is twice his weight. I wouldn’t trust him any electrical cable. He can work on ground breaking theories, but breaks everything what he touches with his hands.
dkjaudyeqooe
Arguably, the idiots of this world done have far too much to nobble freedom in so many different fields. Those people cannot be helped and keep on creating problems no matter what, so why should you restrict the freedoms of those who are smart, capable and resourceful?
Certain professionals should be licensed, because people need to know they are safe, but within your personal domain you should have a lot more freedom.
fragmede
> why should you restrict the freedoms of those who are smart, capable and resourceful?
Because shit causes fires and burns my house down. That’s not to say it can’t be done safely, and if you’ve got the space to do it away from other people, such that the only person you hurt is yourself, then by all means I think you should be able to do your thing. But codes should come into play when it's being done in a garage attached to a home where the partner, kids, and dog live. if I blow myself up, that's totally on me. taking other people with me isn't okay.
cesarb
> As the post explains, the Reliable and Safe bit are really handled by the car, not the charger.
Not all of it; the whole point of having a controller on the wall box is that there's mains power in the cable only while it's plugged into a vehicle (and that this power is removed immediately if the cable is pulled out from the vehicle, which could help prevent arcing on the contacts if it happens while charging).
fr0sty
My understanding of the system is that the plug is physically locked in the charge socket while the car is drawing current through the cable. Thus it is impossible for there to be arcing at disconnect.
gambiting
With the Type 2 cables(common in Europe) - yes, they lock in. Type 1 cables(common in US and few other places) they don't lock in place, you can remove it even when it's charging.
sokoloff
Sort of. There is a micro switch that breaks the proximity pilot signal when you press the button to release the latch. That ends up cutting the power to the main pins before you unplug the cable.
burnerthrow008
> As the post explains, the Reliable and Safe bit are really handled by the car, not the charger.
That is completely wrong.
The EVSE is responsible for implementing a GFCI cutoff as well as an over-current cutoff. Those are both safety features. A failure in the car's insulation resulting in a short to the frame is a shock hazard. A shock hazard also exists if the charge cord insulation is damaged. A bug in the car's charger firmware that results in too much current draw is a fire hazard.
Additionally, the EVSE must keep the contactor open unless the plug is attached to the car (sensed via the [edit: pilot, not proximity] pin). Again, a safety feature because the J1772 plug is large enough for a finger to accidentally contact the conductors.
Yet another is that the EVSE informs the car of the maximum safe current via a PWM signal. Too much current = fire.
The car can't help you with any of those safety aspects.
bastawhiz
My first thought was that this could destroy both your car and your home in ways that insurance might not cover. Simply do not.
scotty79
I don't think its way more dangerous than scented candle lit on a coffee table.
Spivak
A smart electrical switch is going to destroy my home? Guess I've been living on borrowed time with my smart outlets.
marcosdumay
I'm always at loss if the fragility comments like the GP imply are really experienced by the commenter or if it comes from ignoring all the safety around things plugged on the mains power.
Because yes, some homes are really vulnerable to electrical problems. And no, you can't trust any device (high-branded, non-name, DIY, whatever) on such homes. You can't even trust them to handle electricity being available, without any device consuming it.
floatrock
A smart electrical switch toggling your low-current LED lamp based on a motion sensor or other HA automation, probably not.
A smart electrical switch toggling dozens of amps over several hours... this might be getting outside the realm of what I trust cheap chinese amazon products with fake, misleading, or no UL certifications to handle.
Spivak
> dozens of amps
So like two microwaves. It's also not running 20 amps through the Arduino, if the switch the software is flipping is rated for that much power then it's fine.
floatrock
"rated for" is iffy. In the DIY EVSE world, it's becoming well-known that the standard home depot-grade NEMA 14-50 outlet, although "rated" for 50amps, has a tendency to release the magic smoke.
People suspect the traditional duty cycle used in rating these has been more for dryers, kilns, or welders, where they're active for an hour tops or at least not drawing full current. An EVSE can be at full power much longer, making the rating... less reflective of real-world conditions. I've heard there's a new rating system coming out designed especially for EVSE-sized duty cycles.
And that's not even getting into things like torque specs for the connections, etc.
None of this is blocking a dedicated, well-researched, and properly equipped DIYer, but at this level of power, there's enough "tricks of the trade" involved where the risk-to-reward ratio falls maybe outside the casual "buy things off AliExpress and who cares if the magic smoke comes out" range.
At this current, spending an extra couple hundred bucks might be worth it to have an actual company with a non-made-up-syllables name and a non-Shanghai-alley address that my insurance company can go after if my garage goes up in flames because their UL claims were misleading.
bastawhiz
You're not writing the software controller for your switch. You're not interfacing with the firmware of your giant lithium battery parked in your house. You're not soldering anything, or dealing with more than 15a or so. It's really not the same.
manchmalscott
An EVSE (what this project is) only does three things. It advertises the maximum amperage supported by the circuit, it listens for the car to say that it’s ready to charge, and then it supplies 120-240V AC line voltage across the main pins. No EVSE ever, including storebought, is “interacting with the firmware of your giant lithium battery”, the actual charger that turns the AC into DC and shoves it in the battery is built in to the car.
You’re probably thinking about DC fast charging, where the charger is external to the car and connects directly to the battery. Nobody should be trying to make _that_ themselves with an Arduono, sure.
bastawhiz
If the EVSE is talking to your car but not the firmware of the car, then please explain what the hell it's talking to. Is it in the cloud? Is there a little man that lives in my car that replies?
Getting the amperage wrong or sending power when the car is not ready both sound like astoundingly dangerous failure modes for a DIY project, even if the most damage is bricking your car's battery controller.
manchmalscott
if I plug in my phone and my phone isn't ready to start charging (say it detects an overheat, common in Arizona), it just… doesn’t start charging. Just because the cars onboard charger now has power available to it doesn’t mean it has to start charging the battery.
The EVSE is talking to the onboard charger, the on board charger is what actually interacts with the batteries. The EVSE has a specific resistance inline with a comm pin to indicate presence (even when unplugged from the wall) and modulates a frequency on the comm pin to indicate max amperage. The car puts a specific resistance on a different comm pin to request that the contactors close to connect the charger to wall power. Any problems or bugs thereafter are with the onboard charger, not the EVSE.
HeyLaughingBoy
The software controller for that switch was probably written by the new guy fresh out of college with maybe a bit of oversight from his manager. You're not wasting your experienced Staff engineers on stuff like that.
itishappy
Most electrical fires are caused by faulty wiring and outlets, so yes, DIYing your own wiring and outlets can easily destroy you home...
A 10A outdoor charger probably also deserves it's own breaker.
brk
You can reduce this further by saying most electrical fires are caused by people touching things they are not qualified to touch (and by qualified I mean competent, not Certified, or anything official).
If you are not comfortable with high voltage electrical work, or are not familiar with basic components of the electrical code that governs your area, then definitely don't do this. But mass-labeling the work of others as unsafe or harmful is not appropriate either.
jeffbee
Moreover, several extremely large and destructive California wildfires were ignited by dodgy DIY wiring of outdoor loads like hot tubs. Seeing as how many cars are charged outdoors, a faulty EVSE is not something I want my neighbor to try to build.
bluGill
It isn't hard to DIY this right. You need to be careful and understand the NEC (or whatever your area uses), but the work isn't hard. I've seen professionals do some really bad work.
bastawhiz
Most things are easy to DIY, conceptually. It's also really easy to be competent but make a small mistake. It's extremely high risk, extremely low reward (as a function of cost and utility).
itishappy
Sure, but it's easy to fuck up too and the consequences are high. You're gambling with your home and most insurance won't cover DIY electrical work.
fr0sty
> most insurance won't cover DIY electrical work
You have a good source for this? I see claims like this every time a discussion of this sort and they rarely come with any citations.
itishappy
No. It looks like you're totally right and the information I've shared is misleading, so let me do my best to correct that:
Insurance will pay out, provided electrical fires are covered by your policy.
They will then do their best to assign liability and pursue subrogation. If you did the work yourself, you're liable. If you're insured for that work, they'll come after your insurer. If you're not, they'll come after you. If your work is permitted and to code, you'll probably be fine, if not, good luck!
So it looks like you're correct! Unlicensed work appears to be covered, but you may paid AND sued.
HeyLaughingBoy
You would probably have a heart attack if you saw all the watering trough heaters I have running from a single outside outlet all winter :-)
1970-01-01
If it overheats the PLA box and catches fire, very yes.
ceejayoz
Your car, your home, and maybe you.
kuchenbecker
Insurance covers being stupid.
ceejayoz
Not in all cases, contracts, and jurisdictions.
For example, DIYing electrical work in Australia is illegal. https://www.electricalsafety.qld.gov.au/electrical-safety-ho...
> Not only is it breaking the law, but you could also jeopardise your insurance!
> Changing powerpoints or light switches might seem simple, but unless you are trained and qualified, there are lots of risks you just won’t know about. Never attempt to do your own electrical work – you could kill or injure yourself or your family, or start a fire. Always use a licensed electrician.
gambiting
I think we can all agree that Australia is taking it waaaaay too far, and requiring a licenced electrician to change your own light switches is just dumb, and it has nothing to do with safety but making sure that electricians have a steady source of bread doing work that anyone should be able to do with a screwdriver.
Unless Australia has a much lower rate of home electrical accidents than rest of the world, I refuse to believe that this is a good thing.
Sorry, a bit offtopic but that partiular thing really grinds my gears, especially since it covers any cabling that goes inside your wall, so even just running an HDMI cable inside your wall requires a certified electrician to sign off on it.
ceejayoz
I mean, when I moved into my house in the US there were ground wires in the outlet boxes, but none of them were actually hooked onto the outlets. I'd agree Australia's restrictions are too far, but "DIY all you like with things that could kill the next person" has its issues too.
Nextgrid
Unless there's mandatory, regular and thorough inspections of licensed work, making said work require licensing isn't actually going to increase quality. I've seen absolutely terrible, dodgy and unsafe stuff left behind by trained, licensed & well-paid professionals that only "worked" due to a combination of luck & safety margins.
bastawhiz
This is absolutely entirely untrue. Read the fine print on your policy.
itishappy
It often does not. I'd check your policy before doing DIY electrical work.
itishappy
I can no longer edit, but I've learned my comment is somewhat misleading.
Home insurance policies (in the US) often cover negligence including faulty electrical work. If it's in your contract, they will pay.
Insurance companies will then do their job, which is to find someone liable and send them the bill (subrogation). If you did the work, you're the responsible party.
TL;DR: Burning your house down is probably covered by insurance, but that doesn't mean you're not liable.
Kirby64
Just the J1772 cable quoted in this is $140-150... plus however much an enclosure, arduino, etc etc is.
How is this low cost? J1772 chargers can easily be found for this cheap or cheaper. 16A chargers go for $120ish these days, and 32A capable ones are only... $140-150.
dacryn
that is low cost ...
I don't know what you are referring too, maybe it's aliexpress level and they skimped on wire thickness. Most of the cost is the pure copper cable here, which should indeed cost 100+ for a 16ft cable, if you don't want it to melt when it's hot outside.
Kirby64
There are dozens and dozens of J1772 chargers on Amazon with varying price points, and you can easily find 30A capable chargers that offers a 20-30 foot cable for $150.
I don't know if they're skimping on the wire thickness, but frankly I doubt it. Tesla can offer their UMC for $250, and that's a branded product from a car manufacturer and is also capable of handling 32A charging all day.
julienfr112
Can't you use aluminum for the cable ?
bluGill
Aluminum has some interesting properties and if you don't know how to mitigate them can be trouble. I know they can be mitigated, but I also know I'm not an expert in all of them so I won't comment too much. So yes, but only if you are careful in ways most people wouldn't think to be careful.
burnerthrow008
Not for flexible cables.
PaulHoule
I am LMFAO off because AVR-8 is a common choice for a microcontroller for a gas pump as it can handle the buttons and pumps as well as the magnetic card reader, a serial link for credit card transactions, and the ability to drive a simple LCD controller.
sathackr
There's nothing magical about a level 2 charger.
It's a smart relay with a cable and industry-standard connector attached.
That's it.
audunw
Depends on the charger..
It may have integrated ground fault protection
And the "smart" word covers over a lot of potential features, like stopping/starting charging based on electricity prices, doing load balancing between multiple chargers, reporting usage to the cloud, etc.
It's also an outlet where you really want to be sure that everything is professionally done, and up to spec, because drawing maximum currents for hours and hours is very demanding on all the parts. There can be significant heat generated in the wiring and contacts.
turtlebits
NEC 2020 code requires the breaker for an EV charger to have GCFI. Running the circuit, which is not done by the author, generally requires a permit and inspection.
ceejayoz
There is something somewhat magical about a licensed electrician installing a product from a multi-billion dollar company you can sue, though, if something goes wrong and it burns down the neighborhood.
somerandomqaguy
To a degree. The controller has to tell the car what level of power it can draw from the wall.
And it can be as low as 720 watts but I've heard of attempts to get it lower for certain situations where only 400 to 500 watts can be allocated.
KRAKRISMOTT
What about level 3 and fast charging?
sathackr
That's an entirely different animal.
But that's not what the linked article is about.
itishappy
Magic.
joezydeco
Yeah, screw those losers that want UL certification on their chargers.
I don't see a single thermal cutout on this design. I'd be scared.
The PCB is equally scary. How was the trace width figured for the high voltage side? There's also little or no isolation to the low-voltage side.
I also didn't catch if this is a level 1 or level 2 charger. Is that line 120V or 240V single phase? He's pulling 10A which may as well be level 1 household outlet charging here in the US.
sathackr
Most "comes-with-the-car" USA level 1 chargers are actually capable of accepting 240v so operating as a ~3kw level 2 charger if you're okay with hacking a different plug on to it (or using an adapter which may be controversial...)
https://www.gm-volt.com/threads/2016-volt-120v-evse-is-l1-l2...
I've confirmed this first-hand with several different models.
joezydeco
My Volvo EVSE has two tails, one for 110V and one for 240V. It'll operate in either mode depending on the supply voltage you give it.
Symbiote
It seems to be in Europe, so a single phase is 230V (± etc).
sathackr
yes, almost certainly Europe. You can see it's a J3068 connector on the end of the cable. J3068 is basically a 3-phase version of J1772 and is standard for Europe.
The crimped ferrules on the wires is also much more common in Europe vs USA
MarkusWandel
I always have this mild concern in the back of my mind, that the house is absolutely chock-a-block with gadgets that contain LiPo type batteries, that are left on chargers. I try to at least have them all unplugged if we go away for a while, and usually failing batteries have the courtesy of visibly bloating long before they go kaboom (in fact I've had several bloated but none rupture over the years).
Charging an EV in the garage, hmmm. Sure the probability of something going wrong is low, but it it does go wrong, it's a near 100% probability that the house burns down! So I'd rather have a possibly dodgy (but probably not; one can recognize sound enginering at a glance in the photo) charger and car outdoors, than one inside on a name-brand charger.
kgermino
In this case the charger is in the car itself. The EVSE is largely just a complicated extension cord. There’s a lot of ways to mess it up, but none of them should hurt the car battery
diego_moita
But you probably won't need it.
I have an EV, my house is old and its wiring is not very robust. But the garage plug can pull 6 Amps on 120V. That's 720 Watts. If I plug my car when I arrive home I'll get about 8 kWH overnight. On my Kia Niro that's enough for ridding 50 km / 31 miles. Add a little more on the weekend and it should be enough for daily commutes.
In newer houses with better wiring, you might get to 9 Amps and charge/ride 50% more.
jeffbee
By what means is your car informed that it is limited to 6A?
gambiting
A lot of chargers bundled with cars nowadays have a selectable charging speed exactly for situations like the one OP mentions. 6A is usually the lowest selectable speed.
jeffbee
Apparently SAE J1772 defines a 10% duty cycle on the control pilot to mean 6A ampacity. TIL.
ellisv
The charger (EVSE) and/or car usually has a setting.
michaelt
> The high cost of EV (electric vehicle) chargers may lead you to believe that they’re complex systems. [...] They’re actually quite simple — basically just glorified switches [...] It really isn’t any more complex than a $15 smart outlet
Yeah, this alternative is really low cost, except the £80 RCBO [1] he uses for the DC current leakage detection. Something an EVSE does need to provide.
Oh, and also a full-featured EVSE will generally:
* Supply more than the 10A this provides, which you could get with a granny charger
* Monitor the current being drawn, cut power if the car draws more than negotiated, or more than the cables/relays are rated for.
* Have a reverse protection diode on the relays
* Use two double-pole relays controlled independently, so one always breaks the load (putting it at risk of damage) while the other never does (so when the first one fails, the backup is fresh and ready).
* Detect stuck relay contacts
* Sense temperatures on the board, at the main connectors, and monitor the release switch on the cable (if present)
* Manage relay coil power dissipation (a bigger problem with bigger relays, if your EVSE does more than 10A)
* More waterproofing - for example, conformal coating on the PCBs
* Don't put cable glands on the top face of the box, where water can pool up against the seal
* Don't involve a video showing someone poking wires into live electrical sockets, connected to bare circuit boards they hold in their hands.
Something tells me the person who watched this video has never read the specifications of a real EVSE, or watched a teardown by mikeselectricstuff or EEVblog...
[1] https://ecoharmony.co.uk/collections/6ma/products/bituo-tech...
maxehmookau
On one hand, this is epic. Well done.
On the other... hell no.
bloomingeek
[flagged]
notTooFarGone
alright so now you have to maintain two motors instead of one. That'll make maintenance costs so much cheaper...
bloomingeek
True perhaps, but if the electric side has a problem, I can still drive the car.
https://vehiclefreak.com/if-a-hybrid-battery-dies-can-you-st...
gorkish
A hybrid has all the ICE stuff plus all the EV stuff crammed into the same box. It doesn’t seem you are reflecting well upon your own line of reasoning.
ceejayoz
This is not the case for all vehicles.
gorkish
That's not at all my point. My point is a car with 15,000 parts in it is statistically more likely to have problems than a car with 7,000 parts in it. Hybrid vehicles by their very nature tend to have high part counts, lots of custom components to support the hybrid drivetrains, and increased difficulty of maintenance because everything is so tightly packed. IMO it's complete and total insanity to think that long term ownership will be anything but the worst of both worlds; all you need to do is look at the Toyota Prius to understand the long tail is gonna work there.
bloomingeek
https://arstechnica.com/cars/2024/05/automakers-hedge-their-...
Yes, the article talks about the plug-in problems, but it also mentions that consumers are getting cold feet about other problems with the vehicles. There's no owner competition here, just people trying to make an informed decision. Besides, the Prius was a sort of entry level concept that went to production with mixed results. Hyundai is a much better example.
ceejayoz
Barring unique collectors items, what car doesn't have diminishing value?
bloomingeek
True, but if a huge company is willing to lose hundreds of millions of dollars and sell off it's EV fleet, that's gotta be a sign of things to come. (just how much does it cost to replace those batteries and how often? Ask Hertz.)
ceejayoz
Hertz has an extremely different use case than the average consumer.
They put wildly more mileage on cars with drivers who, at best, don't care a bit about the long-term survival of the vehicle. Those drivers are also not typically at home, so they have to find public charging stations rather than plugging in at home at night.
bloomingeek
Your points are well taken. I am an average consumer, one who is retired, I can't afford to gamble on a product that costs so much to maintain. So, I do research to see what is happening in the market. I can't think of a test case better then the one Hertz provides me for free. They ran the numbers and determined EVs just aren't worth the gamble. (most rental cars are usually driven in town, which is mostly what I do.) They're getting out and I'm not getting in.
wannacboatmovie
Burn down your home with this one easy trick!
https://github.com/openevse
OpenEVSE is a properly developed ecosystem, and should be where you start if you want to actually do this. I cannot reiterate this enough; I find it mildly disturbing that the creator of this project fails to acknowledge it.