Good morning all you join me, while i'm making up another cable uh, this one is an xt90. Oh, i suppose that's mail to xt60, so that goes from my power supply actually also made this. So that goes on to the terminals of the power supply and gets me into xd 90 land that will plug on to there, and then this goes to the ant miner. So i'm just going to do the heat shrink of these pieces of heat shrink, get them on there and take it out to the shed and get the miner on my 8 cell battery pack get these shrunk on.

Fortunately, i remembered to put them on the wires before i did. My final soldering, that's the xt90. Oh, these are a bit looser, so i'll have to bias it downwards so that they don't slide up while they're being shrunk, shrink away. Okay, i think that's done good.

Those connectors i just made go here on the output of this buck regulator, which can do 15 amps up to here, which is the board that i put an xt60 on for my miner. Here's the miner it's plugged into ethernet and i took two of the boards out of it, so it's only running on one hashing board and that's so that it would take a reasonable amount of power. You can see from this unit that it's pulling 6.8 amps about 80 watts and the battery voltages have sunk down, as, of course they would to about 3.2 volts per cell, and in this instance, because i have no. I don't think this unit has a low voltage cut off for the input supply.

I don't think it does. I will check through the menus, so i'm relying on the bms to cut the power um now i also want this set so that when the power is restored, it doesn't automatically restart so i'll. Take a look at that yeah. When the vms cuts the power, then the miner will go off and because this power supply won't self-start um, it won't come back on again and that will give the batteries a chance to charge up again from solar.

Now, there's nothing connected to solar. At the moment. That's something i've yet to do. It's been running for about half an hour now and i'm planning to put a second hashing board in because that would probably take it up to about well 12 amps, probably a 150 watts type of thing.

One of the cells is down to three point: one six uh most of the others at three point. One, eight three point one nine! So yes, because this is going to take about three hours - i guess 250 watt hours in my battery pack. Let's call it 240. 80 watts being drawn here in the purple, so three hours of running, i'm getting bored and it's quite cold in here, so i'm going to put a second hashing board in there and uh see whether the system can handle the additional power.

So the first thing i've got to do is switch off the miner, so i'll press the on off switch on there shove the hashing board in. I can't film that, because i don't have my tripod here at the moment, i'll just shove it in connect it up and then that should pull about twice as much power right. I put the second hashing board in and connected it up. That's this one! Here! That's the data cable and that's the power cable.

The cells have shot back up in voltage, of course, because um there's no longer any load on them, so they're all saying 3.26. Now, okay, let's switch on the output. Now initially, it won't take much power because it doesn't hash immediately. It has to go through a boot up phase where it tests the fan, so it'll run that up to full speed i'll film.

The whole of that, because it's quite interesting can be quite noisy. Uh. 3.6 watts at the moment that's pretty much. Just the controller board little board on here.

The early ant miners actually had beagle bones, so they were off the shelf, networking or linux boards, i suppose with networking. Then they started developing their own boards. Okay, so that's getting the fan ready for the fan test. There goes the fan test and 100 watts, i'm quite surprised, so i think it's probably started hashing now, 14 amps and of course the fan will slow down in a moment but yeah, that's quite close to the limit of this power supply.

Its fan has come on. So it's getting warm! That's eased off a bit now that the fan has run down to yeah, pushing 13 amps. Well, that's! Okay! The power supply is capable of that um. Now that's going to pull the cell voltages down more 3.09 and the total running time should only be about an hour and a half.

Now it could easily be because these are quite old cells. They've not been used much, but they are old. It could be about an hour so i'll keep an eye on it. Now the discharge current on the bms is if this would focus uh 20 amps, but that's not it's not quite as stone cold as it was.

I mean it was absolutely freezing before it's. I think slightly warmer and that's because probably 13 ish amps is being called. Ah no, it isn't. Is it because this is 13 amps at 12 volts and on the input we've got 24 volts.

So that's going to be half that current yeah, so there's only about um seven amps running through this, and this is rated for 20. So that's all fine cell voltages are now cell. Two seems to be the um lowest one cell. Two that's the most negative point and it runs down yeah.

So it's this one at the bottom here, that's uh, 3.07 falling a little way behind the others, but the things still holding up putting 160 watts into the miner with two hashing boards. Oh, i suppose we could uh take a look at how much cash it's earned. Well, i've got one cent there of digibyte. All the others are saying zero, but they are clocking up.

There are little bits of litecoin dash. Bitcoin cash is ed cash, dogecoin and ethereum, but up in the today's earnings, only one cent, but it must be getting very close to two cents, because i've already got one full cent of digi bite. So, yes, i'll come back when that is showing two cents. Well, the mining pool is now saying two cents, so that's good uh voltages we've got 3.03 on cell 2 and i was just wondering at what voltage does lithium-ion phosphate start its precipitous fall? Well, i guess i'll find out um everything seems to be hanging in there.

Quite nicely, this is showing 13 amps still sort of 160 watts ish the power supply here. Nothing feels warm, except for this output connector and the heat appears to be coming up through these two um terminals. So i think something's getting warm on the board. It's not the inductor that doesn't feel particularly warm.

In fact, even the heatsink isn't particularly warm, so nothing's warm well. There is one thing: that's warm the uh heat sinks on the cashew and i think actually it has raised the temperature in the shed a little bit. Yeah, it was 14 earlier and it's now pushing seventeen wow now in terms of the two cents that this miner has earned and looking at these voltages, um 3.01. On that i just can't get a good shot of that.

You know 3.01 on cell 2, camera wakey, wakey um. This is not the most efficient miner. This is a z9 mini um. Now, if i was mining using my l3 plus machines, which are down here, the danger with those is that they they take far more current.

As you can see by the enormous amount of 12-volt cables attached to them, but they are more efficient, so they would probably be mining at least double, if not more, for the same amount of electricity. But none of this matters really because this system - i've built at a relatively small scale and it's just a proof of concept. I just want to see if this works, if it does - and it does of course sunlight turned into solar power - electricity stored in a battery and then mined away in a cryptocurrency minor. It's a free money, machine um, yes i'll, build larger scale versions and then i'm gon na have a problem with where to put them.

Now people have been saying um: it's not a good idea to rely on the bms as your ultimate cutoff when solar charging there's the solar, that's not actually hooked up yet, but actually i won't because if you think about it, there's going to be a voltage monitoring Device here which switches on the miner when the batteries get almost full and switches off the miner when the batteries get almost empty. So what will happen? Is the batteries will get almost full before the bms has a chance to cut off because of over voltage? And then the miner will switch on and after a minute or two and we'll go into its high power mode, where it's actually hashing and that'll pull the voltage of the cells down and it'll. Also, when the voltage monitor detects the battery voltage is getting low and turns the miner off that'll also protect the cells from going so low that the bms is having to do the work of switching off the load in order to protect the cells. From going to too low voltage, you've got 2.98 on that is that starting to accelerate downwards, so there will be at least two things that um well.

The miner itself should prevent the bms having to uh do the the switching. There is just one caveat to that, and that is that if the miner can't see the server on the internet, the mining pool server, it won't fire up its hashing chips. So there is an instance where the miner could fail to pull sufficient current and then yes, it would be the bms that cuts the solar off to the battery. What i think i really want actually is a bms that isn't this common port thanks for explaining what common port is um, i really want one that has separate charge and discharge ports.

I might look for that. Well, the vc8s checker is now reporting only 10 of the battery left. Average cell voltage is 2.96, but one of them is low. At 2.85, that'll be cell, two, let's flick across to that and uh yeah top right hand corner cell 2 2.84.

That is starting to fall away now, so it looks like we've got a weak cell or a low capacity cell cell 2. This one down here um, because that's starting to fall more rapidly, now i'll come back when it gets to about. I don't know well when it starts to really speed up 2.65 on cell 2, now and cell 1 isn't far behind so most of the electricity in these life. Pro 4 cells has been converted into money and there is a big advantage in converting electricity into money, because it's actually quite hard to store electricity.

You need this expensive kit. It's actually very easy and cheap to store money. When these cryptocurrencies are on the blockchain, you don't get charged anything for storage and you can store any amount and it doesn't get more expensive. The more you want to store which it does with electricity and in fact, if you get certain types of cryptocurrency, not only is it free to store it, but you actually also get paid interest, so they pay you to store it.

So it definitely makes sense to me if you've got excess electricity that you simply don't have anywhere to put mine it into crypto and store it as cash. I think it makes a lot of sense so 2.58, so when's this bms going to drop out 2.57. I need to be there, otherwise we can't see the numbers now, i'm guessing, based on the fact that when it was charging it didn't cut out until 2.75. I'm guessing this might go all the way down to about.

Well, it could be 2.4 2.3. It could be a very low voltage i'll just keep chattering and filming. I might edit bits of this out because it could get quite boring and if you're wondering why the color of the bench is now all yellow. It's because i turned off the cool white leds because they were causing a nasty reflection in the screen of this battery checker.

Okay, so we're down to 2.5 volts the bms hasn't cut out. Yet i suspect it'll allow cell 2 to go a fair bit lower you'll see how low it goes. Just briefly over here still got 13.3 amps 160 watts going into the minor i've. No doubt you can hear the minor fan whirring away 2.47 and then the other thing on here, of course, is that the input voltage at the bottom there 21.2 volts now that slowing down of the miner fan is nothing to do with electricity.

That's about temperature! It's not very warm in the shed, so the fan doesn't have to run very fast to keep the hashing chips cool 2.44. I'm thinking about well, at the top end, it was a vault over. Wasn't it sorry, it was 0.1 of a volt over. So this should cut out at about 2.4.

If it's going to do the same at the bottom as it did at the top that will kill the power supply, kill the miner. The fan will slow down and stop. The cell voltages should then recover fairly quickly, which may turn the bms back on. What we don't want is for the power supply to auto, restart, uh and turn the miner back on, because then that'll end up end up in a nasty cycle at the bottom of the uh battery packs energy curve 2.36.

What is this daily bms doing? When is it going to uh cut out 2.34? Maybe it'll be two tenths below 2.5. It actually is 2.5, the bottom voltage for lithium-ion phosphate. I thought it was. This is going to go all the way down to 2.3 by the look of it.

Yes, that's quite low, i mean i'm not massively concerned, even if it goes below 2 volts, but i just would have thought that it would have cut out by now. Well we'll keep it going. I presume it's got. Um a discharge cut off system.

Yes, it must do, there's no way that it will allow the cells to go down to nothing well, we'll see how low they go. I'll just have to keep rambling and once again the minor fan has sped up, not because of any voltage change, we're still putting 160 watts 13.2 amps, but v in is quite low. Now it's 19.6 volts on a notionally 24 volt pack, but yeah that's getting well low. I suppose.

Ultimately, the bms's job is to be the ultimate protector. You should have something else in the system to cut you off before the bms says. Well, look. This has gone too far.

I'm going to chop you off at this point but yeah under 2.2. Oh there we go so what was it about 2.18? Now, of course those voltages are going to creep up at some point. The bms will turn back on. So the miner has stopped.

The fan has stopped turning the power supply has cut off when the bms decides to turn back on when these cell voltages creep up high enough, if indeed they do, there may be quite a large hysteresis at this bottom end. We don't know, but what that'll do is turn this psu back on, but hopefully it's set so that it doesn't enable the output and if it does, it doesn't matter i'll, just shut it off, but um yeah i'd. Rather it just came on and these cells were able to recover and then, of course, the next phase of the cycle is to get the solar panel back on the cells, get them charging back up again, not going to happen today, because it's a bit overcast. Well, they will charge but they'll charge slowly.

Well, we've got three volts across the board and the bms has not. Oh, the bms is warm. Actually, it's just off the chill now, particularly on that right-hand end, a bit cooler over there yeah got a little bit warm um. Yes, i suppose it would because, as the voltage of this went down, this of course is trying to provide a constant power to the miner, so the current at this end would have started to creep up.

So, that's perhaps why it's got warm, but it hasn't actually turned back on yet i'll come back when it does well, the cells have recovered to the lowest, one is 3.18 and the bms hasn't actually turned back on, but then this should be programmed to say no, That sort of rise of voltage is not indicative of these things being charged, so i'm not going to turn back on. Maybe if i take the load to the power supply off now. These are not very good xt90s they're cheap and they are very stiff uh. How are we going to know that the bms has turned back on, but not really are we um other than well? The charging side of the bms should be on.

So, if i connect the solar panel through to this connector, these voltages should go up. Should we try that cables, one two, let's connect negative of the solar panel. Like i said it's pretty overcast today to there and positive the solar panel to there do these come up. Is there any current flowing all this point, seven of an amp uh that doesn't tell us, of course, whether the bms uh discharge fet is back on.

I suppose it's pretty irrelevant really, because i need to charge these now anyway. That's enough rambling! I'm going to continue fiddling about until i get too cold when i can't function in this shed um, but for this video, that's it cheerio!.