Teardown of the cheapest portable EVSE available in Australia, the 15A Mida Type 2 portable electric car charger.
https://s.click.aliexpress.com/e/_DEYLWux
Zappi solar EV charger: https://www.youtube.com/watch?v=DwuZJHk5JV8
Forum: https://www.eevblog.com/forum/blog/eevblog-1507-mida-a-surprisingly-good-quality-cheap-evse/
Support the EEVblog on:
Patreon: http://www.patreon.com/eevblog
Odysee: https://odysee.com/ @eevblog:7
Web Site: http://www.eevblog.com
EEVblog2: http://www.youtube.com/EEVblog2
EEVdiscover: https://www.youtube.com/eevdiscover
AliExpress Affiliate: http://s.click.aliexpress.com/e/c2LRpe8g
Buy anything through that link and Dave gets a commission at no cost to you.
Donate With Bitcoin & Other Crypto Currencies!
https://www.eevblog.com/crypto-currency/
T-Shirts: http://teespring.com/stores/eevblog
#ElectronicsCreators #EVSE #ElectricCar

Hi, it's quick tear down time I Got one of the cheapest Evses or electric vehicle Supply Equipment uh as they're known which is basically at what people call an EV uh charger I Got one of the cheapest ones if not the cheapest one you can get in this country. and this one is actually a 15 amp. Jobbie If you don't know, your Aussie plugs the larger 15 amp one as opposed to the 10 amp one. It's exactly the same as a regular R10 amp Aussie plug except the Earth pin is actually bigger on that and that's a 15 amp outlet.

They're not hugely uh common. This is actually can give me 15 amps of uh charge at 240 volts or up to you know, whatever your main Supply voltage is here in Australia it's 230 volts plus minus Uh 10. So mine's typically Uh 200 and around 240 to 245 volts are here at the lab and at home. and uh, this will, uh, just allow me in a portable scenario to actually charge quicker if I've got a 15 amp outlet.

But anyway, this one's about 150 Yankee bucks and it comes from a company called Miter and it turns out that Miter power are actually up like a quite a big maker it seems of uh EV charging equipment and that's all they do. They even make like faster CCS uh DC charges. um yeah, they're You know it's not just kind of some company are slapping together um and EV charger. So I Thought we'd do a quick tear down and take a look at this and it is actually available in a up to a 16 amp version, but it depends on which country you're in.

This is the official Australian certified R1 Uh meets you know all the Aussie standards and everything. So this is limited to Uh 15 amp here. but you can actually select with the button on the front six, eight, ten Uh amps or 15 amp charge current I Don't know why you'd want to go lower, but you know if you're sucking some power from like solar and you need to power some other stuff or something? Yeah, maybe. Anyway, it does have the Type 2 plug on the other end and the cable.

What do we got here? looks uh like it's TUV uh approved? uh 2.5 millimeter, R square. which is what you'd want. uh for a 15 ounce plus the Uh 0.5 square millimeter. Uh, that would be for the control for 50 750 volt um Chengju Pindo Electron code.

Anyway, it looks like it feels like a decent quality bitter kit, especially for the money. this is only 150 Yankee bucks. Bare rock bottom price for an Evse charger. Anyway, let's tear it down.

I think we've got some screws here. Let's check out the build quality. So I've done a video on my uh Zappy charge and in that um I've demoed and explained how EV charges work. This is not a charger.

Okay, there's no active circuitry inside here that uh charges the car. The Charger's actually inside your electric car at least for the Uh AC charging for the really, uh, high power uh CCS uh, DC Chargers No, they charge directly into the battery pack and that's why they have to be hugely complex and expensive things that you install at, you know, a service station. But for AC charges like this one and one's up to like seven kilowatts or whatever. Or it can be even 22 kilowatts depending on whether it's a single or three uh, phase car.
My 2020 Ionic EV is only capable of single phase charging, so it'll only do up to seven kilowatts or so. And that's what my Zappy charger does at home. But the AC charges. Um, all that the Evse here does.

Even though we call it a charger boxes, all it does is actually switch through. It's just got a big relay in there that switches through the AC and then it's got a little micro in there which just sends out a Pwm signal to the car to tell it what charge current is available and then the Char and then the car will actually regulate that. So right off the bat here. Oh I'm seeing metal threaded inserts.

That's very nice. Oh geez, that looks nice. Really liking the look at that. look at those current Transformers in there.

That's really neat. just right off the bat. Loving the crimped um, and yeah, they've got a shape proof washer on the bottom of those I Love the inner face on that. This is really good.

It's got an O-ring uh, seal around there for some weather uh proofing and that goes into the top board which just has a micro on there. that's there's just one button on the top and there. Well, that'll be the LCD driver will power it up at the end of this and I'll show you. But what's going on? What's this over? Oh, that's just a lead.

Um, yeah. Lead bar graph does like, you know Earth leaky jar detection, thermal overload protection, and stuff like that. But basically it has a big relay switching in here and all it does is essentially if the conditions are right and it detects that it's plugged into the car, and uh, it sends out a Pwm signal to the car. The car will then know which what power levels is available, then the car will only take that amount.

But basically all it does is switch. Um, the active in neutral will be switching both just through and that's basically it and the car will charge the EV battery with its own built-in charger. So this thing is just a very smart uh relay with some um, you know, safety features and some Pwm stuff. But isn't that layout? Very, very nice.

I'm impressed with that. We can easily get in there, measure stuff, it's repairable. That'd be the Pwm control wire going over to the Uh car. Looks like it's got another Phoenix connector under there, but that's not going anywhere.

so maybe there's another in interface model or something. But yeah, it looks very well clamped down here. I'm just liking the build quality of that. That looks absolutely first class.

And you've got to remember, this is like bottom of the line pricing too. Like you can pay two to three times the price of this. Small touches here. they've just put some solastic down for whatever that is on there.

I Don't know, it's just a cap. I See, it's labeled C. Yeah, then we've just got is that a current? Transformer Is that like a hall effect? Uh, Joby in there? But anyway, yeah, that'd be measuring that looks like it's measuring the active. So this relay here would be switching the active like that and that'll be the active going over there.
and then this relay here would be switching the neutral which is the blue one. you know colors. Um, here here in Australia we have brown for active and blue for neutral and green for Earth. So that'll be measuring the charge current.

and then this one here would be measuring. uh, the imbalance between active and neutral. So this would be like an earth leakage circuit breaker type thing. Oh, I had that back to front.

This is actually the output here and this is the input. I should flip it around all right. So I've got Mains input over here Okay, so basically if the current flowing through the active like this out here into the right out here into the car and it doesn't come back. if it's out of balance with the current that flows through here, then you'll have a differential in the current between these two.

They won't cancel out each other out anymore and it can detect the difference as probably that uh, circuitry down there and it can. That's an Earth leakage circuit breaker. Well, it's basically a Core Balance relay thing and then that will trip and disconnect the whole thing as a safety feature. So that's really nice.

And what else we got in here? Well at the top here looks like this is just the mains. uh, power supply. which you know. so this would just be the mains coming in here.

Again, we've got another. or maybe these Phoenix connectors are here for factory tests because I don't know what version of the product would use. Phoenix connectors? maybe I don't know I don't know. Anyway, um if you know, leave it in the comments or it wouldn't be too hard to do better nails.

When you've got the huge big contacts like this that you could have, you know, a big lid with pins that come down and make contact with these and then you can test your boards at uh, the production factory uh stage. But anyway, this has been isolated switch mode supply for power in the circuitry. a bunch of series resistors up there, so they get in. they're putting those in series so that they can get a high voltage resistor in there to get the voltage drop on that.

As for the relays in here, what do we got? HF Okay, so the big question is are these Japanese relays not Japanese relays? Unfortunately, uh, these are Hong Far brand, but they are a serious Uh relays for this sort of application and also certified as well. So these are actually 50 amp relays. So um, they might actually use this same board in uh, they might I think they make a 32 amp version of variant of this. Um, it looks slightly different, but you know, maybe they use the same relays in that as well.
They certainly could. and these are actually latching relays so they don't need coil power to keep them in the latch. Star State and I don't know why you'd use a latch in relay for this sort of uh thing. It's not like the coil current consumption is an issue and really I would uh prefer that like if it lost uh Power I don't want it to be latched in a certain State I'd rather see it like like normally open and then it has to require the Active Electronics to then keep it energized and switched on and the input is fused.

As you'd expect, you can see that little SMD jobby down there, that's for the main switch mode from the mains input side. Nice. Anyway, Interestingly, there is an NTC uh, thermistor temperature sensor input there. I mean the micro has probably got a temperature sensor in it as well because I can't imagine that it's not measuring the internal temperature in a sealed enclosure design like this.

My guess would be that given the proximity of this thing they would actually have in the higher amp models, but not in this one, they would actually have a thermistor measuring the temperature inside the mains. uh plug. Because when you start talking 32 amps, you start talking. you know it's serious.

Like 15 amps is like like you know I wouldn't bother. That's why they haven't got it uh fitted in here. but uh yeah, it can become a problem. Um, you know you get dodgy connections on your Mains input plug and that can overheat and that can ruin your day.

So yeah, you would want to add a thermistor in there and then they would use a non-standard Mains cable and they'd have like an extra R pair going up there to the thermistor and then that would just plug in there and that doesn't seem to be another input there for like any sort of you know moisture. Ingress uh sensor because like this is a portable one so you might use these like out in the rain back side of the board, only a single sided load and they've got some extra current carrying capacity by uh, removing the solder mask and leaving the solder plate on there. But yeah, that's exactly what I expected. Nice spacing.

everything's hunky-dory Nice solder joints on there too. It's all looking pretty. Schmick All right, let's just go briefly through the PCB and down the bottom here. This is actually interesting.

This is an St Micro Joby so there's tons of like Asian Alternatives but they're using an ST1 A Viper 27. why can't all chips be given decent names like Viper 27. I Love it instead of like Lm12345? come on, give me anyway. it's an offline, uh, high voltage uh converter here.

So exactly what you expect. it's just an isolated offline converter. optic upload. feedback that's in there somewhere.

but um, yeah, playing vanilla stuff. I Just a bit surprised that they used an St part there. I Didn't look at what brand caps they're using on the output here, but yeah, so you've got your Mains input here. you've got your common mode choke, you've got some X and Y class caps here by the look of it.
and the, um, just the offline. uh, conver better and there's your secondary. So I'll flip to the back side of the board which is like you're looking through the board. so I've flipped it and oriented so we'll see like the outputs down here like this.

and if we flip over, you can see that there it is there There's the secondary output there and you can see that that powers all the stuff along the top side here. So that includes this chip. We'll take a look at this one, we'll take a look at and this one here. This one.

obviously it's right near the Pwm output here. it would control the relays as well. Can see a couple of uh back EMF diodes in there can we? Um, this one here is obviously to do with the current sense here. The Core Balance uh.

relay like this and this one over here I Thought was just like a driver going over to like the LC like a shift register or something. but no it's not. It's more interesting than that because this is the mains input here and you'll see that it's actually going off through these caps, right? So you've got a capacitive resistor divider thing have happening here. So what is this chip like I Thought you know right near these pins I Got fooled.

it's actually this thing. We've got a high Trend Tech Chipset here. What it is is an energy monitoring chip I Didn't expect an energy monitoring chip. There you go.

22 bit Sigma Delta ADC I Expected just basic current limiting. you know is like limited too. um x amount of current. Like there's no need to measure the real power and apparent power.

but maybe it's just for like overload and it's maybe it's cheap as chips I'm here all week. This one over here can measure the current that's doing the current measurement. so I don't know how that's getting back over there here like this. Ah, there you go.

There's the Uh current Transformer there or the hall effect sensor and that's going these traces going back over there. So it is actually measuring the current and the voltage. so it can actually measure the real power consumption, real and apparent power consumption of this thing. So according to the manual, um, comprehensive as it is.

Um, it seems to only have a voltage and current display. It doesn't have a powered display, let alone a kilowatt hour like an energy display to tell you how much accumulated energy is put into your car. And this one in here is exactly what you'd expect. This is, uh, the chip that connects to the Um hall effect current uh, sensor thing here I don't know what it is, but that's an FM 2147 and all this circuitry will no doubt match the application.

Note over here: this is a Food and Microelectronics Group Company Limited and this is a very specific Earth leakage monitoring chip. It's designed for exactly this application here. and uh, it's got a block diagram here, but it's also got an application schematic I betcha. This is going to be pretty darn close to the application circuit and now it's got the input specific input there for the current.
Transformer Here just measures the imbalance. I don't know what you set. set it to like. There's no adjustment thing in here.

Maybe it's like, you know, fixed to some standard 30 milliamps, 50 milliamps something like that current I Don't know. Maybe you'd have to translate it from the voltage coming out I Don't know. Anyway, yeah, that's a dedicated Earth leakage. Um, the breaker chip as you'd expect and this up here I Thought would have been the micro to drive this pin, but it looks like it's an St Um 2902.

just a Joe blogs um, quad op amp. Anyway, that makes sense because you've got a capacitor dropper. Well, you've got two capacitor droppers down here and then a high voltage series resistor and there. the trace.

You can see that going off over to here so that's doing some sort of monitoring. Uh, for the car side over here. but anyway, the micro must be over on the main board and the main board. as you can see over here that is an Stm32 micro.

So once again, a bit surprising that they didn't use some. you know? Asian Asian Saw Star Micro in here because they already had the development experience for the St micro and this flat. Flex Ribbon here is for the switch which is on the front panel there and it's just got some leads there which then connects through here and Bob's your uncle these dip switches here I Would uh say that they set the model and region because they sell these into different countries. There's different standards.

As I said for this thing, this actual model is capable of 16 amps, but they limit it to 15 amps here and stronger. Don't have a 15 amp outlet in the lab or I did although when somebody took it out when they uh I rented this place out and they renovated. but there it is. Oh no, it does have kilowatt display there I think oh, it does have kilowatt hour.

There you go. Didn't have that in the manual 24 degrees. so yep, it's got an internal Uh temperature sensor as I suspected. Um, it doesn't know the Earth is uh Missing because it's got no way to detect that I don't actually have the Earth connected.

Please excuse security. The model didn't have time to build the scale or to paint it. Put a two point 0.7 K from the earth through a series diode through to the control pilot pin here and then that will determine that it is connected. Is it connected? Yes it is.

We're going to win a chicken dinner, but it's not actually starting the charge current yet. to do that, we have to put the car. Actually, this is normally or this stuff's normally inside the car. To do that, to make it, uh, switch through.
we have to put a 1.2 K in parallel with it. Boom! I Heard a relay switch and it's charging. There you go. No worries, it's well, it's not charging, it's switched.

The AC through works and I want to see what happens if I imbalance the uh thing with the diode here. Will it disconnect? No, No, it's still. it's still charging so it doesn't need the diode. It looks like it's not doing the um, the imbalance diode protection thing.

Okay, so I've got the diode shorted and no, it's still. no. it ignores the diode. So I I don't know if that's a specific standard I Don't know you'd have to go into it, but it looks like it doesn't Uh, it doesn't matter whether the diode's there or not.

some charges do apparently. Anyway, it seems to do the business and uh meets the basic uh requirement there. You could get a resistor divider box out now. I won't bother.

By the way, when you switch it off, it doesn't seem to unlatch those uh relays when it loses power, but it switches. Uh, the relay back off as soon as you immediately apply power. So yeah, not a problem. I Guess this was supposed to be a tear down video so you'll leave it at that 10 day.

I Don't know you might see an operational thing of this on my Uh EV one day. but actually I'm very uh impressed with this and look, we can just change that, can we? Yep, yep, six amps through to 15 amps and that's it. But I'm very impressed for the price point I like expected this to just be slapped together and shot equality. and I'm impressed by the quality of the case too.

just the real thick um ABS construction you saw like the ribs side and everything it's supposed to be IP67 rated. it looks its weather rating looks really good, but IP67 is supposed to survive like a one meter water immersion for up to 30 minutes. I Don't know if you'd whack this in under one meter of water for 30 minutes, but you know it's at least Ip66 maybe in theory. IP67 I Don't know how they've done the ceiling around the uh screen and stuff like that, but the end.

but the O-ring seal in here and the ends and everything looks, uh, hunky-dory So as far as weather resistance and ruggedness goes, wow, it's unbelievable for the price and the quality of the design and construction of this thing. I Was quite impressed and this is like a bottom of the price unit. There's no need to pay more. Um, then you know this, what was 150 US dollars.

So if you're after an additional Evse for your car, usually they're included when you get an EV but you might need a second or a third one or something. or a replacement one. And um, yeah, there's no need to spend more than this. I'm quite impressed with this.

uh miter, uh it. It's pretty darn good. So yeah. I Just didn't expect that for the price.

Anyway, thoughts and comments are down below. We'll catch you next time.

Avatar photo

By YTB

21 thoughts on “Eevblog 1507 – mida: a surprisingly good cheap portable evse”
  1. Avataaar/Circle Created with python_avatars Erik J says:

    Faster charging, amps here and there yada yada yada….
    Takes about 3 minutes to fuel up a car with gasoline or diesel and off you go…further…with a million gas stations all over the country 👍🏻
    EV rubbish.

  2. Avataaar/Circle Created with python_avatars DeKempster says:

    Would like to see the earth wire longer than L/N. If the cable would be janked out the earth would disconnect last

  3. Avataaar/Circle Created with python_avatars SDGB says:

    Dave, I love you! 🙂

  4. Avataaar/Circle Created with python_avatars Adam Baker says:

    I do love it when you say "yankee bucks"…

  5. Avataaar/Circle Created with python_avatars Sina Sattari says:

    I would have put the screw lugs further apart avoiding the possibility of ring terminals rotating and causing a short across.

  6. Avataaar/Circle Created with python_avatars Jari Naumanen says:

    Ground wires should always be longer than phase wires.

  7. Avataaar/Circle Created with python_avatars Cătălin Alb says:

    Zappi Charger is still the king of them right? @ 10 times the price…

  8. Avataaar/Circle Created with python_avatars Cătălin Alb says:

    Dave, Wiha or Wera as for the best screwdrivers ? 🙂

  9. Avataaar/Circle Created with python_avatars 陈北宗 says:

    The company that made the device is related to State Grid of China, and that company has rigid safety standards for its products and services, That may just propagate to its subsidiaries.

  10. Avataaar/Circle Created with python_avatars David T says:

    Should the earth lead be longer?

  11. Avataaar/Circle Created with python_avatars Hu Sun says:

    Looks like designed by one of the daughter companies of the State Grid. These guys dont mess around, absolute all of their products spare no cost, but not necessarily good looking. For normal Chinese companies, at least the phoenix connectors won't be there during mass production.

  12. Avataaar/Circle Created with python_avatars Jonathan Musgrove says:

    Dave throw it outside overnight with the rain you'll be having you'll know if the ip rating would hold up
    the 8amp feature would be good for those who attack the earth pin with a grinder (not using safety glasses just the safety squint) so it can fit in a standard 10amp socket

  13. Avataaar/Circle Created with python_avatars thekaduu says:

    EVVBlog…

  14. Avataaar/Circle Created with python_avatars Hermann Schaefer says:

    Also available in Europe, as modell MIDA-EVSE-PE16S with a higher current rating: 8A 10A 13A 16Amp. I wonder if there are any differences, I guess: no. ^^

  15. Avataaar/Circle Created with python_avatars DrScopeify says:

    One of the most dodgy electronics out of China I have run in to are AC to DC converters, I am trying to power a 12v DC tool with 120v wall power. Super iffy. I had one meltdown and another smoke and maybe catch on fire but I am not sure.

  16. Avataaar/Circle Created with python_avatars Jason Fritcher says:

    Is it just me, or is that EVSE allowing charging with a floating ground blade? Ground faults are supposed to be checked for at power on time, as well as at the start of every charge cycle. How is that working, or is this EVSE ignoring that part of the safety standard?

  17. Avataaar/Circle Created with python_avatars Ed C says:

    In the UK most electricians will tell you these are only for emergencies as PEN faults (when the neutral in the street drops so neutral comes live, and so does earth) just want to kill you at any moment. The same electricians will go lash up a load of class I outdoor lighting in the flower beds of your garden where the kids play. Its a huge money spinner installing fixed charge points at the moment here, part of the sales pitch is scaring people off of using portable EVSE's and weirdly (or not) the NICIEC and IET are behind it.

  18. Avataaar/Circle Created with python_avatars tx5brent says:

    As an Aussie who has 15A equipment in my garage, I know exactly why you may want to limit the current to 10A……

  19. Avataaar/Circle Created with python_avatars Bryan S says:

    I’m probably a small minority, but I still can’t wrap my head around buying cars with expiration dates. Lipo batteries do not last, I truly hope something better comes around soon, but what a disaster for the environment at this point in time.

  20. Avataaar/Circle Created with python_avatars looksharpPT says:

    I Dave, I have one just like that. Working fine since May/June 2021. At the time, it cost me about: 90~100€ (delivered).

  21. Avataaar/Circle Created with python_avatars Rheingold says:

    Those relays can go into one on one off when there is a power failure. My unit needed me to manually switch both off to recover. I also have a Khons 22kW adapter, pretty bullet proof and a gen2 Tesla HPWC which has an ABB 64A contactor and is converted to charge from an 12kWp off grid solar (charge rate according to solar input).

Leave a Reply to Ed C Cancel reply

Your email address will not be published. Required fields are marked *