Good morning all and a happy new year 2022, i have a potential new project based on what's in this bag, which i bought from third rock energy inside the bag. We have this so this box of tricks, which has a little display up the top there and a button. Labeled amps, is actually a mode 2 portable ev charger or what's known as an evse, an electric vehicle supply equipment. Now, coming out of the top of this box is about three or four meters of cable and on the end, is this plug, which is a manicures or type two electric vehicle uh plug and in there we have seven pins and on the end of the wire Coming in at the bottom here, unusually for, what's colloquially known as a granny cable, there is a 16 amp commando plug.

So i'm going to call this a grandpa, cable and that's because in the uk, granny cables are typically well they're terminated in a standard 13 amp plug, but typically they're set to tell the car to pull only 10 amps, and that is because well in uk plugs There is a fuse, and at 13 amps, it's kind of getting hot, not quite in a semi-molten state, but certainly giving off a lot of heat. Now, there's no fuse in this commando plug, and this unit is rated at 16 amps. This is a 16 amp commando plug. This unit has settings which go up to 16 amps and you can put 16 amps into your electric vehicle, so one of these things called granny cables or granny chargers.

Well, the idea is you keep this in your car and if you get very low on juice, while you're visiting your granny, you can, with the 13 amp regulus plug just plug into a standard household outlet, and although it's quite slow, you can charge your car. If you need a bit of extra juice, so why did i buy this special 16 amp granny charger? Well, i have a 13 amp or set to 10 amps standard granny charger that came with the car. What i wanted is some electric vehicle supply equipment, which this is rated for: 16 amps, because 16 amps times volts. Well, let's work it out so 16 times.

Well, let's do 230 first! That gives us a 3.68 kilowatts and if i do 16 times, that's 3.84 kilowatts. Now the solar panels on my roof are 3.8 kilowatts worth of solar panels, but my inverter limits that to 3.6 kilowatts. So the point is, i'm only able to generate from the roof of my house 3.6 kilowatts on the best of the sunny days, we're likely to get a few months. Hence and therefore i needed a unit that could go up to that rating and 16 amps is about right, so that i can charge my car just from sunshine now.

The idea of this video is that it's a tear down of this unit or a strip down as i like to call it. So, let's have a look on the back. We've got these uh hex screws. There are some caps i've taken, four of them off already, but these ones should come out fairly easily yep.

So it's a case of getting these caps out undoing the screws and taking a look at what's inside this unit right, let's start undoing screws, and i will that's a bit tight. I will attempt if i can, to remove these cables, so i can sort of fit this on desk because it's constantly wanting to be pulled off the desk by those really quite heavy cables. So, let's get all these screws out. This unit's rated ip67 ips ingress protection.

67, the six is protected against access to hazardous parts. Dust tight and the seven is protected against. The efforts of temporary submersion in water test requires 30 minutes at one metre depth. So it's pretty waterproof i'll, put a link to the ip ratings chart that i'm using.

Oh, it's on mauser.com, a bit of confusion about what's inside these boxes, a friend of mine, who's got an electric car calls this the transformer, as though mains goes in and some sort of transformed voltage comes out, but there's no transformer in here. It's simply mains in mains out you put mains into the electric car, and really all that's in here is a couple of relays, one that cuts neutral, one that cuts live, and those relays, of course, will drop out. If there are any issues like current leakage to ground that sort of thing, but there's also something else in here and it's a control signal that goes to the car to tell the car how much current it can pull. So you might say: okay, car, don't pull more than 10 amps if this were a 10 amp granny cable, because my household wiring, and indeed the cables coming in and out of the granny box - are only rated for 10 amps.

So don't go trying to pull 32 amps, which would be 7.2 kilowatts and that's typically, the maximum. You can pull unless you've got three phase um on the type 2 input of a vehicle, because the cables and the relays and all the rest of it aren't rated for that. So there's a little signal in here. It's a little square wave goes out to the car and tells the car you can pull a maximum of this much current right.

Let's lift the lid and there's nothing attached to the underside of the lid and that's what's inside lots of sort of power supply type stuff right. Let's have a little look here. We've got incoming mains cable with neutral line. I think it's called, although i'll probably call it live and what they call pe, which is protective earth going onto the board going out to the vehicle.

We have live neutral, protective earth that goes out to the car and also this thing called cp, which is control pilot. Now it's a square wave and it's fixed at one kilohertz and it oscillates between plus 12 volts and minus 12 volts relative to protective earth. And, as i say, it's the pulse width of that square wave, which tells the car how much current it's allowed to pull. On the 230 volt or 240 volt ac mains, so here are the two relays that disconnect uh live well, that'll be that'll, be neutral and this one will be live um.

If there's a problem here are a couple of current transformers. This one's measuring both live and neutral, and so what this is looking for is a difference between the current in neutral and live now. If there is a difference between neutral and live current, this will have an offset current on it and that will indicate that some current is leaking somewhere, in other words, all the current coming from live. Of course, this is ac, it goes backwards and forwards, but let's call it all.

The current coming from live is not returning through neutral because some of it is leaking somewhere and that's considered a danger because it could be leaking through a person. And so if this sees any offset - and i think it's quite small amounts - um six milliamps comes to mind, but i'll have to do some checking on that. Then these relays will drop out because it'll say there's something horrible happening over at the car end. We're switching off um this current transformer here is only measuring live, so this one is probably just measuring overall current going out to the car, and i know that on the display, because i briefly powered this thing up um, it does have a current measurement of electricity.

Going from your main supply to the vehicle right, what else we got on here? Well, there's a micro controller down here. We'll have a look at that a bit later and there are various connection points i think, there's a programming interface for the microcontroller, eight megahertz crystal for that um. There's a power supply unit of some description here, there's a bridge rectifier here so probably taking mains and creating some sort of low voltage supply for something possibly the microcontroller. Perhaps uh surgery there a couple of mobs couple of class y capacitors, this uh dual wound choke, which could be common motor.

It might be differential mode, i'm not entirely sure on board fuse here, probably for the electronics in here. This is marked two milliamps slash two milliamps, and my guess is that this is a power supply, a fairly low power power supply, generating plus and minus 12 volts, so that it can be used to pro to provide this cp signal. The control pilot signal, which has to go plus 12 volts relative to pe and minus 12 volts relative to pe. That's the protocol for controlling the car's current draw.

So i think that's the power supply that generates the positive and negative voltages for that cp waveform um. These relays not sure if you can see this yeah rated 20 amps at 125, volts ac 16 amps at 250, volts ac, so this being a 16 amp unit. It's using these relays right up at their maximum rated current, the full 16 amps at either 240 230 or whatever your mains happens, to be a little thermistor there, two wires running up and that's actually stuck to the side of the the live relay. This is the relay on the live side.

There's live there, so the there is on the front panel um a temperature reading that temperature is actually the temperature of the relay controlling the live connection from incoming live to outgoing live. So what i wanted to do see how easy it would be. There's an led stuck to my screwdriver, see how easy it would be to disconnect these um mains and it's not too tight. I think these are ring terminal, so i think these are going to have to come right off.

Let me just check, there's no mains coming in here. No there's, no mains i'll, perhaps power this up at the end. Is that a ring yeah. So there's a ring terminal, so i'm going to take these off and attempt to get one of these cables off and then i might try and get the other one off now undoing this uh clamp bracket that holds the cable into the body of this thing.

This, i think, is finger tight, yeah, so i'll undo that and see. If i can withdraw this cable, i think i have to take that bracket off. Get the cable out of the unit make it much easier to continue taking the unit apart right. That cable does seem to be with drawing out of the unit.

That'll make life a bit easier and on there there's a bit of heat shrink tube uh, which is where this metal clamp presses down on the cable. So that's out, let's try and get the other one out. Incidentally, the price of this unit is, i think, was 229 pounds, they're really quite expensive, i think justified by the sort of fat cables and big connectors. It's a lot of money, though, and i don't know that looking at it - it's quite justified, but this is where the money is at the moment.

Isn't it i mean i've, looked at these type 2 connectors and on ebay. They started around 50 quid, but on aliexpress they're about 25 pounds, but that's a lot of money for just a few connections and a plastic body right attempt to withdraw the cable that goes to the electric vehicle. These are slightly more formed these wires. This is an interesting cable because it has three fat cables in it and two of these much thinner cables, which are really signal cables.

One of them has just been cut off. That's the pp signal, the proximity pilot and i have a feeling that will be implemented in the manicures plug the type 2 connector plug at the far end. I've got a feeling, it's just a resistor in there, but i can't quite remember the details. We can have a look at that another time, okay, that one's out so now this box is free to be taken apart on my desk, so next undoing the four screws that hold the board into this case um now under the board, there is going to be Some connection to this clicky switch and also there's a display on there, which i think i've seen color come up on.

So i think it's a color tft right, so this board now lifts out. Is there a ribbon, cable or something on here uh? No, there are two further boards. Oh that's right, there's a line of colored leds here, which i think lights up different colors depending on what this unit is doing. That looks like the display um where's, the clicky switch it probably oh, no, it's there.

Oh it's actually! On the back of here yeah, it's just a tactile switch on the bottom here, so i should be able to disconnect these to plugs. So in here we've got a huge rubber membrane on the amps button there, which just transfers movement onto the back of this main board, which we'll have a look at in a moment. This is uh an led board, there's just a row of leds on there. That's a one one, one seven, so it's just a regulator at 3.3 volts that one - and this is the tft display.

Now we've got vss vdd clock, sda scl, i know blk. So maybe that's blanking. I don't know s d, a s c, l, r s, r s, t c. So is that i squared c or is it spi? I can't quite work it out at the moment, but anyway those goes to those go to the main board.

So, let's take a look at the main board, so just having another look at this, i don't think there's anything on the back. Oh, there are a few things. Yes, there's ic3 there. Oh there's an eight pin, there's a inductor there power supply of some sort.

There's what looks like a poly fuse there? Another eight pin chip here some diodes. Oh a crystal at a very daunting angle. That looks like it's for this chip. I don't know what that is uh.

Is that perhaps something to do with the display? Yeah? Quite a lot of wires, or maybe the led driver - quite a lot of wires - seem to be running up here into this lot. Um the screen one seems to be mainly clustered around here. Is there? Oh, that's probably coming straight off the micro controller, so i'm guessing that this is just one of these breakout units. I can probably see the part number that actually and it's just driving all the leds on the led board.

So going back to the top side, incoming mains on this big terminal block here, outgoing mains and the cp signal the control pilot. Now that appears to there's a tvs here and that's probably just to clamp any transits, because you've got to remember that this cp signal goes down quite a long wire to the car. So this clamps out any transients that are above the voltage of the positive 12 and negative 12 control signal, which i believe this is the power supply for can't see that just at the moment. But can we see yeah? You can just see the slash 2 milliamps.

What it says, 2 milliamps slash, 2 milliamps, so i think it's a dual uh power supply unit in there now, let's see if we can see this microcontroller, let's have a look. Yes there we are. It is a gd32f cb t6. Let's have a quick look for that.

Well, i've just found a data sheet for this device. This is um, as i say, gd32f103xx. So in this case it's uh whatever that said c6 or something uh arm: cortex m3 32-bit mcu, so not an arduino which is a bit of a shame. There is access to programming for this chip, but i don't know arm cortex.

So i'm not going to attempt to make any changes in there um. When i said i was, this was a potential project. I was thinking um either hacking into this. If it was um an arduino e-type based thing, it isn't, but there is a project called open.

Evse, which is an open source, arduino-based or um, uh 328p based uh project to build an evse, and it had occurred to me that i could potentially just use the box that this came in the cables and all that stuff and build a new board based around The open evse based on a 18 mega 328 p and build a whole new board. It would have to have relays. I was hoping that the relays would be on a module inside here, but no they're actually on the pcb. Well, that's fine! I suppose and um rebuild this as open evse, because what i want to do with this is: i want to control the current now.

I have a funny feeling i don't know this yet because i've not actually powered this thing up when connected to a car um. I want to be able to control the current that this sends out through the cp signal to vary the current that the car draws to match the solar curve of a typical sunny day or even one, with sort of deep dips. Where um it's sunny and then a couple of clouds pass by and then it drops off at the end, i want to be able to measure the output from my solar power system and tell the car to draw an equivalent amount, or maybe slightly offset to give The house a little bit of electricity as well, so that i'm effectively charging my car on pure sunshine. So certainly this board is a reasonable size.

It's about uh 16 centimeters wide. What is it that way about eight centimeters? So it's a two by one aspect: ratio. Um, i could probably fit open evse onto a similar sized board, put connectors in similar positions to take the cables and yes, effectively rebuild an evse, just a slightly different one, with a 16 amp maximum rating in this box. Uh, which usefully has this sort of um uh silicone bead running down that round there, so it's essentially waterproof to ip67.

It looks like if i undo all these screws here. I could probably take the display and led module out and then i would build open evse with probably a little oled just to give me essential information on the screen, but yeah. That's potentially. The project that i want to do is to replace this board and put open evse in that box.

Now this chip on the back here is an rn8209, which is a single phase. Metering ic, so is that measuring the ac voltage, because i know that on the display you get to see the voltage. So that's possibly what that's doing seems a bit over the top just to show you the voltage um. Could that be measuring current as well uh? Possibly that's! What's measuring the current through that there are the pins for it uh through that current transformer there um, so it's nothing to do with the led.

That's probably driven directly from the cpu again uh down here clustered around the cpu. We've got five pin header reset clock, dio ground and 3.3 uh, there's a header here which says ground rx and tx. So we could see if there's some stuff coming out of rx and we could also try injecting stuff into uh, no injecting stuff into rx and looking for stuff on tx. But i don't know what the protocols are for this unit.

So it's very unlikely we'll be able to change the current like that. The one thing about this unit, i'm thinking, is that it's probably not possible to alter the current with the big amps button. While the thing is actually in use, i suspect that'll be locked out, but i don't know that yet so we can find out. Also here there's a link um ground to boot or boot to 3.3.

So you can either ground the boot pin or you can pull the boot pin up to 3.3 there's also a switch there. I don't know what that does, because it's not attached to anything that's accessible from the outside of the unit, so possibly that's also related to booting the cpu. But i don't really know what that's all doing right. I'm just going to put this uh back into the box, and then we can just briefly power.

It up see what's on the display, and that will probably be my strip down for the day. Oh, i've just discovered that there's a protective peel sheet on this front panel probably should have left it on, but there it is i've peeled it off and it's wonderfully smooth. Well, i've put the output cable back in so i just need to connect these connectors. These ring terminals back into their respective places.

That's protective earth there right. That's the input mains cable back on the unit, so i think what i'll do now is put the back on couple of screws and flip it over just plug it in i'll put it on a mains power bank i'm not intending to plug the other end into Anything yet and we'll just see the display come on, hopefully right. I have here a uk mains plug to commando socket so i'll plug that into the commando plug, and we can power this thing up right, i'll, just turn on the mains basic one hope. Oh, yes, that's working! Fine! So here are the blue leds.

I think blue means standby. I've got a feeling. Green means charging and we'll have a look at this display a bit closer. So it's in standby mode, it's in the six amps max.

So the the square wave signal is one kilohertz, as i say, but it's got a pulse width and i'll print the chart out in a moment that's indicating to the vehicle. Now this isn't plugged into a vehicle, of course that it should not pull no more than six amps, that's changeable by the big amps. But if i press that it goes to 8, 10, 13 and 16, that's kind of for the uk and european markets and back to six um, so we've got a voltage measurement here. 228.3! That's coming from one of the um power banks: it's not coming from actual mains 22 degrees celsius is the temperature of the live relay.

There's no current being drawn, of course, because the output type 2 plug is not connected to anything. We've got a kilowatt. Hours accumulate a cumulative counter here and there's also a timer here. I assume that's how long the vehicle has been on charge and there's a flashing symbol of that menicus or type 2 plug, which i assume means plug the plug in now, and so just a spec.

For the control pilot signal, this is from the wikipedia article on j 1772, but it also applies to iec 62196, which is the sort of uk and european spec type 2 plug j1772. This one here was the original um type, one plug, which i think had five pins. The type two plug has seven pins because it allows for three phase. We'll have a quick look at that in a moment, but if you tell the car, if you want to tell the car you can pull up to 30 amps, i think 32 is common as well or maybe it is 30 actually for 7.2 kilowatts.

Then you put the pwm out at 50 percent if you wind, that down to 10, and that appears to be the minimum, which there may be issues with that. I quite like it to to have a lower minimum actually for when, for when. The sun is going down at the end of the day, but the minimum appears to be 6 amps, which is 1.5 or a bit less kilowatts, and to tell the car to pull no more than 6 amps. You send out the control pilot signal at a 10 mark space ratio and then just a quick look at this um plug.

I suppose it's a socket, really there's no mains on here, because the two relays inside here are both off and there's the control pilot pin. There's the proximity pilot, which i think must be just wired with possibly just a resistor inside this connector, have a look at that one day: uh, there's protective earth neutral and live one and for a single phase system, and my car is only single phase and typically Cars in the uk um might choose to be only single phase, because most residential properties only have single phase mains, but there are the other two phases. If you want to have hardware in there for three phase and some vehicles, i think the the zoe have three phase charging uh. You can populate these two pins for live two and live three, but here only using live one neutral, protective earth control pilot.

This is where that um, plus and minus 12 volt square wave comes out one kilohertz 50 for 30 amps uh 10 for 6 amps and the proximity pilot signal. There haven't gone into much detail on that because i don't really know it. I'd have to look it all up um but, as i said, i think it's connected in the plug and just a quick look at this cable. This is the one with the three uh mains cables: the brown, blue and yellow green for live neutral on earth.

So we've got three donut g is 2.5 millimeter squared conductors and also two 0.5 square millimeter conductors, which are the black and grey wires um, which are control, pilot and proximity pilot. The pp1, the grey wire, seems to just be cut off inside this box. The black one control pilot does go to the electronics, so that is an evse. Sometimes these are called granny cables or granny chargers.

This one is a grandpa charger because it's the 16 amp variant, not the usual 10 amp, with a 13 amp plug variant. That's what's inside and that's a potential project going forwards to link the charging current um of my car directly to the amount of solar power. That's been generated from my solar panels, but for the moment cheerio.