Good morning, all today, i'm going to take a look at the contents of this envelope, which i've already opened sender's address. Is there didn't think i should show that um and it's this device, which i got from a seller in the uk, and i've got a couple more of these coming they're all slightly different, because this is kind of the main switching element for my solar battery and Cryptocurrency mining setup, while i'm dabbing, i might as well open it uh. This is the switcher that will switch on the cryptocurrency miner when the battery voltage is low and switch it off. No, the other way around switch on the mic when the battery voltage is high and switch it off when it's low.

In other words, it is a discharge load controller. So, as i understand it, what you can do with this thing where's, my pointer, is set an upper voltage threshold with these four buttons down here. This, incidentally, is an xl semi, um, switching regulator of some sort and there's little inductor um, but the main microcontroller is actually under the display there. I don't know whether i'm going to be able to show that i could just see rows of pins.

I can't really illuminate it in such a way that you can see it, but it is oh yeah there we are, i think you can just see the pins along one edge, so the microcontroller is under there. Now it's going to be doing a voltage measurement and also driving that display yeah. So you set your upper voltage limit and your lower voltage limit and i believe there are two modes you can either set it so that it's a charge controller so that when the battery gets to a low potential, the relay will kick in and you can have A mains or whatever charger coming in to charge the battery back up and then when the battery gets high, the relay will drop out, but you can also set the other mode, which is a discharge controller. So when the battery gets to a certain high state of charge, you can turn the relay on that will then discharge the battery into a load and that's precisely what my system does.

I want the battery to charge from solar and then discharge into the cryptocurrency miner. So that the solar panel is never sitting there doing nothing, i want it to be working all the time um. So, let's power this up and take a look at these upper and lower settings and see if the relay kicks in um. I do believe that this is v in and ground for power to power.

This thing, i think it's got quite a wide range. I think it was four to forty or something um. This is v in for measuring the voltage and i think what you do is strap the v minus there to ground they're, probably linked on the board uh. Yes, they are look v minus to ground um, and this, i think, goes up to 30 volts and then the relay you've got normally closed and normally open connections at a common center tap, which will be that one um are these separate connections here.

So you you connect it all up yourself, yeah, let's power it up through there, so i'm going to connect this um connector now v in positive, so that'll go upside down like so, and i'll stick 12 volts in it. I believe it is 4 to 40 um on the input. Oh, that screwdriver is no good. So here's one of the connection diagrams.

Oh it's 6 to 40 on the input. Well, that's fine from ebay and we have the fire line and the zero line so positive and negative. You put your positive through the relay. The normally open would be my guess that goes into your charger and that charges your battery with the device measuring the battery voltage on this input and this input just supplying power to this relay unit.

So, let's just supply power to the relay unit and watch the display come on right. 12. Volts from the battery is outside my window and there it is - and it says u-1, of course we're going to have the usual problem here. But you can't really see the display i'll get some red insulation tape on there peel this one off, because we don't really want two layers of this stuff and cut a bit of red and stick it on now.

Can we see that better? On camera? Oh yeah? That's better so it says u1 and now uh naught point naught. Oh up no down doesn't do anything, oh switches, the dot on and off interesting. I don't know what i'm doing at the moment. This is the usual story.

Set u1 fine up. Q2. Oh, so that's the different modes now i'll print those out actually because they're quite interesting. So here are the six modes, they're rather small.

Sorry about that um, okay, u1, charging measurement when the measured voltage is lower than the lower limit. The relay pulls above the upper limit voltage, the real and it's cut off uh. Well, the relay will drop out. I presume right charge measurement time control, so you can probably set a timer not interested in that discharge detection.

When the measured voltage is lower than the lower voltage limit. The relay is off above the upper voltage limit. The relay pulls, don't think we want that. I don't think we want discharge time, detection, time, control voltage in the range and voltage outside the interval outside the range.

Oh well. Actually, then, maybe we want discharge detection when the measured voltage is lower than the lower limit voltage. The relay is off lower than the lower limit yeah. The relay turns off above the upper limit voltage, the relay pulls.

So that looks like the one we want u3. So let's go up to u3 there. It is and uh what do we do? Do we press set oh nl1 naught? So let's set this to about three volts good. It's got a oh that speeds up, which is interesting.

Um, it's only accurate to point one of a volt, but that might be okay set ul upper limit one now. Why would it be one well i'll say that too i'd know four volts and i presume it remembers all this stuff in the uh non-volatile memory of the chip set nl one three ul one upper limit: what's n l then lower limit minimum limit ml is it Says nl? Is it ml? I don't know uh stop, stop. No stop doesn't do anything set set, doesn't do anything i'm stuck. Maybe you have to unplug it um you're bored now, so i'm gon na try and play with this work out what i'm doing and i'll be back right.

So i've gone into the menu and set it for the three volts low limit and the four volts upper limit. I've put a 100 microfarad capacitor on the measuring input and a 10k resistor. So i can charge that capacitor. So, let's charge it and take it above.

Four volts: oh, it went up quite quickly. The relay pulls in when it goes down below three volts. The relay drops out: let's try and widen. Why did that? Go up so quickly when i touched it on there, i suppose it is 12 volts.

Maybe i'll have a higher resistor than 10k but um. Yes, that certainly seems to work below three and the relay drops out. Oh, is there a little light on there? Did i see? Yes, there is there's a blue led, so you can see what the relay is doing down below three volts and that drops out good. Okay, let's set it to a wider range apparently to set it, you have to press and hold, but then you have to let go so slightly odd.

So it's u3, it's in the mode that i want um now nl is lower limit. I don't know why. N l is lower limit, but it is so let's bring that down to 2 volts and then we'll go up a limit and we'll take that up to. I don't know 6 volts, so we've got a wider range nl2.

Oh it's not going to tell me. I think it's done so, let's press and hold set. I think that's what you do and we're back to u3. So now it should trigger at 6 volts there.

It goes and then it should drop out when the capacitor voltage drops below. I think i set it to 2 volts. Didn't i? Yes, i need a higher value resistor here, i'm going to get a 100 k right with the 100k. That is definitely going up slower, so we need it to get to six volts to trigger the relay to its on state.

Oh, that's going out really slowly i mean have i got dodgy cable here or something probably i think i have oh or is the imp input impedance of this overwhelming that's dodgy cable? Doesn't it i'll use another cable right? I've got a 20k resistor um, it's 0.1 that doesn't particularly matter. Okay. Let's take it up up it shoots above six volts, which i set the upper limit to the capacitor voltage decays and below two volts. The relay drops out right, so you get the point.

That's that um, i suppose we could try another mode, so the charging measurement is u1. Let's set that one so press and hold set uh down to u1 set lower limit um. Well, that can be 2 volts. Well, the limits can be the same.

Actually uh set. Do i have to change that slightly 2.1 set? Yes, i do that's really stupid upper limit six. Well, let's go to 5.9 set and i think we have to press and hold set right. So the relay has now pulled in because it's below my lower limit of around 2 volts, let's take it up to my upper limit and the relay drops out.

So this would be if you were charging the battery the battery is getting low. Now, oh, it's going really low, and so your external charger is now switched on through the relay and will charge the battery back up. So let's charge the battery back up and when it gets to six volts um the charger cuts out and then the battery is allowed to slowly discharge. But this upper limit and lower limit thing means that you can set a really large hysteresis and that's going to be fine for turning on my ant miner, when the battery my lithium iron phosphate battery reaches a certain voltage and i'm kind of thinking about 27 and A half volts for the upper limit and probably about 22 and a half volts for the lower limit.

But that's just what's in my mind at the moment: let's just do one more of these voltage in the range which is u5 press and hold the set u5 set. I don't know uh. No, i think we've come out press and hold set u5, but i don't know what to do now. Do you go up? No, that's change! That must be set.

Oh there we are so the lower limit is 2.1. So we'll leave those limits the same and come out of that. No, that didn't wasn't long enough, but you don't get the feedback. You just have to hold it for two seconds and hope that you're right so voltage in the range.

Now, as we go through the range two to six volts, the relay should come on to so it came on and went back off and then, as we fall back down into the range the relay is on and as it drops out of the bottom of the Range the relay goes off and then the other one u6, there's no point doing that. It's the other way around outside of the range. Yes, i mean it's got a reasonable set of um working parameters. Now one possible problem - i foresee, is this 10 amp relay my ant.

Miner probably pulls getting on for 20 amps at 12 volts, so 24 volts it's going to be around 10 amps, so this relay is going to be working close to its upper limit um. I really wanted one with the 30 amp relay and i have subsequently found one that's coming from china. This one came from a uk seller i'll put a link in the description below because i just wanted to get hold of it quickly, and i think this is going to kind of do the job for now now, apparently, you can connect v in and measure positive Together and the two grounds are connected anyway, um and that allows you to use the measured voltage also as the supply voltage, and i think that's fine, because the v in was uh six to forty. Well, that's my battery is within that range.

So that's fine and then the relay is going to turn on the power to the ant miner, when it's within my ranges, so i suppose i should set my voltage ranges really. I know that i want u3, which is this discharge detection mode lower limit, i think, is 22.5. So, let's, oh yes, that goes quite quick, uh. Okay, it's all a bit quick! 22.5! Let's set that up upper limit, i think was 27.5.

Oh, it does go very quickly. 27.5 set up lower limit 22.5. Well, that's fine! So i think i can come out of that. What, if you press, stop? No that doesn't do anything which is really annoying right.

I'm out it's very weird! This i want to come out. No i've got all that. I know all that stuff, it's all in there. How do i get out? Oh driving me mad? Oh it sound now this stop button.

It says off or on. Well, it doesn't apply to the relay. I wonder if it applies to these there's a couple of connections up here: we've got an output and a ground, and i think you can control something else with those. Actually, that could be quite handy because you could probably control a 30 amp relay board with that, but there's also this tx and rx, and i think it can send out data on tx and rx.

I have to put a scope on there. I suppose um, probably showing the measured voltage interesting, look what i found a little miniature oscilloscope. I don't really remember who sent me this so if you sent it to me well, thank you um it's convenient because it fits on my desk. Look at that aron tech.

So it comes with a probe which plugs in to the top um. I just wondering if i can see anything coming out of the that should be all right, because if that swings up and shorts the cap, it doesn't really matter. Does it. I want to see.

What's coming out of the tx anything, oh, i think we saw something yeah now can i vary the time base. Oh possibly i'll have a place. If i can get this to work right after much fiddling about i've, now got the uh serial data on the tx line going into the scope it's triggering properly. That red mark is the trigger um.

I could put it on two milliseconds per division, but then you can't see all the data on five milliseconds per division. You can see it all and it seems that um it sends a burst of serial data. I think every one second, it said in the uh instructions on the ebay listing, but it's certainly sending something out. Yes, it is still triggering that is still changing.

So, yes, you can get a burst of zero data. Um parameters, like i think, the timers and the measured voltage. If i push the measured voltage up, we might see i'll put it on five milliseconds. We might see some changes to the data as the voltage drops back down, but of course this doesn't have any sort of serial data interpretation software in it, but um it shows that it can be done.

The next thing i want to do is put a little led with resistor across that secondary output and see if it mimics what the relay is doing and i've set this back to 2 volts and i think 5 volts for the lower and upper limits. I've put a blue led on there with a resistor, and now, if i take it above the upper limit of 5 volts, the led comes on, and it just mirrors this led here and when it drifts back below 2 volts, they both go off so yes, this Is just a method of daisy chaining to another unit, so that could be one of those little 30 amp relay boards, which could be quite handy. So now i need to connect um the voltage switching device through to the buck converter. This will switch at the 24 volts, hopefully under 10 amps.

So what i want here is, i want, switched high current positive to come into common and go out of normally closed. I also want that positive line to go into voltage measure and also to go into here, which is the power source for this module um. Then ground will just bypass this unit, but it must also have a wire feed into the negative point here to provide power to this unit. So i'm going to make this up in xt90 so that this can be inserted into my line of cabling.

So this is my current uh male to female cable, which runs into the butt converter. So what i want to do is cut the red put that in normally open the black will run through to the connector on the other side, but only the thin black coming out to provide a ground reference for this and i'll need two thin reds coming out. The thick red actually will need to run into common here. I need another red running across to there, which i can probably just daisy chain across, but i'll need another red coming out of this side to run into the supply input.

Now i've got a number of these things: um, it's just a sort of pin which you can crimp on. Of course, i solder them, and i found one in blue and so i've put it on there and it fits quite well in this. These are very small diameter uh apertures for these terminal blocks um, but i've got any more of these blue ones only found one so the red that comes round and goes into there i'll have to do some other way. It's all going to be a bit uh hazard, this one, unfortunately right, the only other blue one that i could find in this fishing tackle box, which only now has yellows and reds um was this fork terminal, so i just cut that off and that blade will Fit in there it's very ugly, but it's all i've got right, it's finished, but this is terribly messy because the board is just laid out in such a way that everything's, yes, well, you can see can't you, but anyway, uh incoming positive.

That goes into the common of the relay via this uh connector, which is the only one i had outcoming, is normally open, so that will close and provide power to there. That provides power to my buck converter. To take the 24 volts down to 12 also got a couple of wire feeds into here to power this unit, and the wire here takes positive of my battery and puts it into the measurement input. Don't need to bother with the ground so that should work time to take it out to the shed one other thing: i need a coupler to put the solar in and that's goes to the bat.

No that goes to the battery. Oh, is that the solar - oh, have i done this wrong, i don't think so, solar battery and on to the rest of the circuit. I think i need to flip that one over actually now i'm in luck, because it's sunny and there's sun on the panel. So, let's hook this up and i've hooked up the voltage trigger unit to the battery, i just need to connect the solar in, but this is all rather awkward.

This has to go upside down. It has to sit kind of under that, but i'll just mount the camera now this hasn't triggered because oh well actually there's an on and off thing, that's off that's on, but it still hasn't triggered because it's 26.6 and i've set it for 27.5. So, let's connect solo, which has to sit under here which isn't ideal, but it should kind of work. Oh yes, that's lifted the battery voltage to enough to switch this on yeah.

These voltages are shooting up. I think the battery is essentially fully charged, but i'll use. This as a pointer, no i'll use this as a pointer, that's gone to 3.74. The bms, oh, has now turned off yeah.

This is weird because the solar panel is periodically driving the ant miner directly and that's not good. I yeah. I really want to partially cover the solar panel, while this is going on actually, but the ant miner is sort of working but yeah the um bms is cutting in and out not ideal see if the antminer does fire up actually but where it says 34. Of course, it's being fed directly from the solar panel, the battery has essentially disconnected itself what's odd, is that the battery will have disconnected itself in a charging sense, but it shouldn't have disconnected itself in a discharging sense.

I suppose the point is this: voltage is higher yeah. I don't know that the ant mine is terribly happy with this i'll turn it off for the moment, which i can do there cool off, um i'll have to think how that's going to work. Yes, i think i'll need to partially cover the panel right panel partially covered. Let's turn this back on.

The miner comes up i'll see if it goes through its full boot sequence now and starts pulling from the battery back in a mode. Okay, the miner has gone into its fan test phase and at some point, it'll start pulling it's 300 or so what 270 is it doing it? Now? It might be 24.8 there, and then this is uh been programmed to drop out at 22.5. So the miner will now take a slightly reduced current because the fans run down, but the hashing chips takes the bulk of the current. So that's: okay, yeah, that's um and then the back converter will warm up so yeah.

I'm just going to play with this and see see if it works right. I've uncovered the solar panel, so that's going to hold the whole thing up, so it's quite possible that this would mine continuously um or near continuously. Actually, the solar panel is producing 203 watts. Yeah, the miner's probably pulling uh more than that i'll go roaming actually, because i can't really see what's going on so there's the miner that's pulling about, i think from memory 270 watts we could do with a a watt meter in this path.

Here perhaps i'll do that what's coming in at the moment is 26 volts, 7 amps the sun is out. You can see that from my bench there and that's giving top right 202 watts so yeah the battery is holding up because of that. Well, there's no sense in shading the solar panel, because i really want this to mine for as long as it can on solar, i mean if a cloud comes over, it's going to um, allow this voltage to dip, but hopefully not so much that this relay will Drop out so that rudo's hot, actually, oh, it's warm yeah. That's warm with probably almost 10 amps going through it.

Oh well, we'll see how it goes. Uh that was a bit alarming. The display has just gone off, but i remember reading that there's a five minute. Timeout or something uh now, if i press stop what's gon na happen, i think i have to press and hold stop to change that, but stop might stop it.

So perhaps i won't when i do have another voltage thing on here, so 25.0 volts on this little checker so that i could use instead of that, oh well, i wasn't brave enough to do it on camera, but a single click of the stop button. Uh brought the display back on, and actually i think, if you press and hold this, you can put it in a mode where the display stays on continuously. Yes, i didn't mention, that's quite a nice feature. Actually, isn't it so the only alarming thing here really apart from these exposed, bolts i'll, do something about that um.

Is this relay getting warm? That's not ideal, really um, but this does have that switched output which could drive another relay and in fact the other two similar units to this. One of them has a 30 amp relay so that might be more suitable for this setup. How's, the butt converter yeah. That's just warming up nicely.

I was just looking at the correlation between this display 24.5 and the balance checker. The battery checker display 24.7. The lowest cell is 3.01, so we're just about to head into the two point. Somethings region and this correspondingly is going lower.

But this is set to 22 and a half, so i'm waiting for that i'll put this back actually now, that's quite good display, because i know i know, which is the lowest cell doesn't really matter, which is the lowest cell. There is quite a difference between you. Can see the average is 3.09 and the lowest sell is 3.0. This battery is getting quite considerably out of balance, and yet i did completely top balance it and i think, that's because of the springiness of these cells.

I'll have to come back to that, but i just got this feeling that these cells are electrically springy, but anyway uh yeah, so 2.99 on the lowest cell 24.6. There 24.4 there it's not bad correlation, not too bad. This does seem to measure reasonably accurately. That really is still warmer than i'd like it, i'm thinking 30 degrees yeah, possibly a bit more 35.

Maybe it's just a bit warmer than i'd want 2.98, there now 2.97, so i'll come back when this is getting down. Well, when this display is getting down towards 22 and a half and we'll wait for the relay to drop out, this is varying quite a lot. I'm seeing up to 400 millivolts of variation 23.6, 23.5 now up to 24. It was it's not anymore and i'm just 23.9 there, so yeah 400 millivolts of variation, just wondering if it's um noise coming back from the butt converter, it's more likely actually variations in power being drawn from the ant miner.

So that's fine! 2.60 on the lowest cell. There yeah just waiting for this to get down to 22 and a half, and i'm just checking the earnings on my chromebook. So i'll just have a look at that. The battery in my camera ran out and the power bank that it's connected to was off.

I didn't notice now the sun's come out on cue 90 watts coming in from the solar panel. So that's going to lift the voltages up, but i want this such that the hysteresis is um sufficiently wide. So i've set it to 27.5 that even with a full on uh. Oh this, four amps coming from the panel 106 watts, even with full-on solar.

This wouldn't flick back on again, because that would be a mistake, because these are not very well charged. Maybe that upper limit would have to be raised a little bit now. Do i have enough faith in this system to just leave it here, uh overnight, nothing's gon na happen. Of course, this display will blank out because of the timeout, which is a good thing.

I suppose i've been leaving this thing on actually um day and night and of course this is oled and oled tends to suffer from burning, so these lighter meeting diets will gradually reduce in intensity, but that should be fine. These are only about 15 pounds. I think so could get another one if it burns out, but so far it's been fine um. Yes, i mean this is just now.

The solar panel is charging. The battery cell voltages are coming up. As i say, the battery is way out of balance. So balancing is something i need to look at yet, balancing achieved by this bms, which is just out of shot, is hopeless and not worth worrying about.

So we need something a bit bigger than that, but uh yeah. I mean something like this voltage trigger board uh, or this one, possibly with an external 30 amp relay um would even be better, i suppose, to have mosfets um. It's raining now. Can you believe sun's out and it's raining weird uh yeah mosfets, possibly rather than a relay - i don't know, but anyway, that's the video.

It was about this um next step, don't know whatever turns up in the post, but for the moment cheerio uh. This is worth documenting, we're pushing 170 watts from the panel now because there's just a little bit of a clearing in the sky and that's pushing up to 27.1, which is not far off my 27.5 upper limit. Maybe i need to raise that to 28 or something yeah. I've just raised the voltage on here the on voltage to 28 volts um, the sun's fully out now, there's a little bit of blue sky and the cell voltages are being pushed up against their springs.

Their electrical springs because of the current 5.7 amps. Yes interesting i'll, just rov, oh no! I can't because there's no power in the camera, but um. I did see about eight amps briefly on the display for the solar panel, but it's dropped back and that's because the voltage has fallen back because the panel's actually warming up because the sun's been on it for a while. So that's interesting: you can get bursts of really high current, which will push these further up against their springs and what we don't want is for this thing to trigger unnecessarily.

Just because there's a lot of current pushing these cell voltages up. If the current falls back and if the panel uh warms up and therefore it's voltage drop so overall power drops, then these cell voltages will fall back a little bit and we won't get a false trigger on here. Yes, getting this balanced is well, no, i don't mean the cell balancing. I mean the balance of the upper and lower trigger points is quite interesting.