Good morning, all this is a battery monitor um. Alternatively, it's a v8 meter. I think it's also a coulomb meter. The manual says slightly more on it.

Yes, it's a dc voltage and current meter um. Also, a coulomb meter, um model kgf series specifically model kg140f and it's made by junk tech or specifically the hangzhou gents instruments, company limited, so the story behind this is that the manufacturer got in touch and said we are the manufacturers of the vat1030. Now that was a 100 volt, 30 amp voltage and current monitor. This is in a different league.

Let's get the current shunt out. So that's the screen module. This is the electronics module and this is the current shunt with a few other bits and pieces. But this current shunt is pretty massive there.

It is it's enormous i'll get some light on it, so yeah, the current chant is this enormous slab of metal um with these sort of veins running between these two blocks, and you can see there are little cuts there. Little nicks, which presumably has been done to calibrate this unit, there's a pcb on the top with a jst connector. These uh bolts they're, not eight mil, because my eight mil connectors simply don't fit. I think these are 10 mil they're, absolutely massive uh also supplied.

These aren't supplied also supplied in the bag of it. So these uh look like pure copper, absolutely massive um crimp terminals. I suppose they are, and they say on there, 400 amps. So i'm pretty certain.

This is a 400 amp current measuring device, i'll just measure the diameter of this bolt. That's supplied and um yeah, that's 9.7! So that's going to take a 10 millimeter ring terminal. That's pretty big uh lots of other bits in here, including there's a temperature sensor there. So the display presumably has temperature and also uh temperature cutoffs, and that sort of thing big spanner for those nuts and bolts um, there's also various interconnecting cables.

But i saw these and these do fit over these bolts. So i don't know whether these perhaps go on here and provide mounting points for attaching this to something, since it doesn't have mounting points of its own right. Let's get the remaining bits out of the box. There's this.

I think it's an rs485 cable, i think with rj45 no there'll be something else connectors. Won't they there's also the screen unit and there's the electronics box unit there. So in the manual here there are two wiring modes: there's self-powered mode where the unit the electronics box is powered from the battery you're measuring now that means that you've got to have a supply of between 10 and 120 volts or you can do external powered mode Where you have a separate battery to power this unit, and that, of course, can do zero to 120 volts. Well, i'm quite happy with the 10 to 120 volt range, so i'll set up something that lets me do uh, self-powered, wiring mode, so in amongst the parts supplied.

Are this short length of black and red wire? I think i'll solder that to an xt60 and then i can plug a lipo into here, which will be about 16 volts or something like that. This will go into the little green connector, which is that and that goes into the electronics box, so i'll solder. That up and we'll take a look at what comes up on the display, i'm even going to use the little screwdriver supplied to fit these wires into this supplied block, so vsense is at the top, and ground is at the bottom, so i'll screw those in right. Let's power this up with this lipo, so about 16, volts, uh right so most definitely v sense is parse.

Ground is neg flat. Side of that is pause that lines up with that. So it's definitely around. Let's plug that in oh we've got a flashing green light.

There, so i guess the next thing to do is put this uh data, cable, it's well! It's data and ground and five volts uh between the electronics box and the display see what happens all right, let's plug that into there. Oh, yes, that's quite nice. So 15.43 volts, of course, there's no amps, because there's nothing being measured by the shunt. We could connect that via its cable to the shunt connection, which i believe is there, the current sensor, the middle one i'll do that and see if well, there shouldn't be any offset, should there, because it's measuring zero volts.

Here i don't know what circuitry is on this uh pcb. Actually, let's just see what happens right. It's interesting one way around the colors, don't quite line up with ground and vcc, but the other way around they do so i'll. Do it that way around? I wouldn't actually matter, i don't suppose which way around i did it, but vcc ground scents are on blue and yellow.

Let's plug that into this thing, see what we get and yeah there's a small offset current there. Now there is a calibration procedure where you can set that back to zero, but i shouldn't worry about. Actually that is reading 300 milliamps, which is quite a lot um. So we'll look at that bit later on, but that's that part uh working now there's another cable in here which was the thermistor.

So let's get that connected yeah at the moment you can see that it's got dash dash degrees celsius. So, let's plug this in uh. I think it's got to go that way. Does suppose it matters really.

I don't think these are polarized components. Are they and we've got a reading of 20 degrees c, which i guess is about right for this room? Oh more, like 18, really now notice that the current has gone to zero, which is interesting. I wonder if things have to warm up a bit or maybe there's an auto calibration thing, i'm going to try and put some current through this shunt with this battery and this bulb it's going to be an absolute lash up, but let's just see if i can Get something going through there and we can't see the display. So let's work that way, i can't even see whether that's lit up.

Yes, it is, and we've got 400 milliamps. Well. That seems to work. I mean it's not very precise because it's designed for enormous great currents uh.

This is interesting when the customer starts the meter for the first time or restores the factory settings, the display will have a small current deviation under normal circumstances, when the meter is not connected to load. At this time, the charging state error and the discharging state arrow will jump back and forth, which means that the meter is being calibrated automatically. This phenomenon will last about 30 seconds and then the current will return to zero automatically. At this time, we need to press the key for a long time to confirm that the current returns to zero so that the meter can remember the zero state and the zero current will not jump again, no matter whether the machine is switched on or off or Restarted so it does do an initial current calibration.

I need to press something for a long press. I don't know what, let's press, ok for a long press, maybe that did something i don't know right. So what can we do with this thing? Well, let's press set - and there are all sorts of parameters here - language, clear, current, clear data and powers present a preset amp has remaining brightness lvp ovp. Oh, i need to scroll down to go to the next lot.

Ocp ncp opp otp recovery time standby time voltage calibration current calibration temperature calibration address. I think so. You can have multiple units delay time. Current ratio monitor on and off relay mode restore all now, if you do restore all, i think it goes through that current calibration thing again, so one of the first sections in the manual says preset the battery and power value.

Now this is currently saying uh. If you can see it's 79 percent, but i don't think this is just some guess based on voltage, i think what this does. Is it genuinely coulomb counts, so you set the amp hours total capacity, and then you tell it where you think the battery is currently so you can either fully charge it and set it to 100 or you can fully discharge it and set it to zero percent. Let's see if we can set this to, i don't know 100, it's just measuring the voltage of that at the moment.

So it doesn't really mean anything. So, let's go into settings and go to amp hour preset. Now it's got 20 amp hours, i'm going to change it to 24. Oh okay! Yeah! You can do that in increments.

Okay set, so is that 24 amp power sets go back into set. No, it's still set to 20 amp hours. Why didn't it remember it uh? Maybe you have to okay your way through each of the digits. So that's the 0.1.

That's the units, tens, hundreds and thousands. Now, there's no highlight so. Maybe if i press set now, has it set it to 24 amp hours? Yes, it has it's remembered it, and now it's saying 66 percent uh state of charge and there's an amp hours remaining, so that's obviously set to uh or was set to 16 out of the 20 amp house. This was previously set to it's now.

Of course, 16 amp hours out of 24 amp hours, hence the recalculated percentage value. Now there are a whole lot of sections in here like under voltage protection over voltage, protection, uh positive over current protection, negative over current protection over power protection over temperature protection, and they all say at the bottom. The protection function needs to purchase the relay. If there is no relay, please do not set this value and install a relay in the circuit before it can play a protective role in breaking the circuit, so you do have to purchase your own relay now.

There is a relay output on this box. Here, output control we've got a ground and out and a v external. So this is where you hook up your relay and then, if any of the protections needs to disconnect the circuit, it will do it via your external relay, there's no relay built in, and that makes perfect sense because you might be trying to switch 400 amps and They're not going to put a 400 amp relay in this little box, however, sneak peek, 500 amps, 24 volts now there's a whole bunch of stuff. In addition to this reverting time protection, this appears to be, if you set it to zero, then if a protection kicks in and then the situation resolves itself, it will immediately switch the relay back on, but you can put a time delay in that enter standby time.

I think that's the time where the display turns off voltage calibration current calibration temperature calibration set address. I think that's for multiple units set delay time, better, read that i don't know what it is. Okay, this is for any of the over voltage over current protections. That sort of thing you can tell it not to trigger immediately but put in a small time delay, so that's presumably to eliminate jitter if you've got something that const is constantly triggering in and out of range uh monitor function, oh turned on using the computer software Control, i don't know what that is relay mode.

You can switch that on and restore factory settings. I think that's pretty much everything in here: yeah the wiring modes, the connection of the relay and its external power supply. Now, whether that can be ground, whether that is ground referenced to the input voltage, i don't know i'll have to check whether you actually need an external power supply. There is an app uh bluetooth, so i presume one of these boxes, not sure which one which i might open this up in a minute.

Uh has a bluetooth module in it to run the app and that's pretty much it so yeah. Let's take out the um current shunt, i know not meant to pull on the wires, but it's almost impossible to pull jsts out without doing that, because how do you get, i suppose you can just about get a grip on that uh display unit can come out And my power supply can come out yeah. Let's take a look inside here and see if this has got the bluetooth. Oh, that's the little switch for whether you're using the two-wire powering method, which is what i did just um using v sense to actually power this.

If you switch the little switch to three wire, i imagine oh, it's quite deeply buried in there. I imagine it wouldn't power from v sense. It would require um to put the v external in, so it probably just switches between v sense and v, external to root power into the electronics inside here right inside the electronics box, there's a little two wire and three wire switch. We have this.

Okay, so looks like we've got a buck converter here, so that's probably to bring whatever voltage you put on here and remember. This can go up to 120 volts down to something that this can work with, looks like that might be a microcontroller. Everything is etched all the chips have had their tops etched off, including this mosfet, which seems rather pointless because that looks like it's the relay switching mosfet, it's going to be a generic part. So quite why that needed to be etched.

I don't know so. Let's have a closer look at this regulator, possibly, but i can't tell you what anything is apart from that one ohm resistor, because everything has been etched um that chip has got a crystal next to it. That's probably oh wait a minute. We've got an antenna there that could well be the bluetooth uh chip.

That's interesting! It's actually integrated on the board. This, then, is highly likely to be a microcontroller there's the programming interface, for it is there another crystal around here: no, it's probably using its internal rc. Oscillator not sure what that eight pin chip is. There are several of them.

They could be op amps or something simple like this, so not a huge amount in here, but everything you would need to perform the functions that we've seen and yes, the bluetooth app, is probably running in conjunction with that chip there and just for good measure. I thought i'd take apart the display, but there isn't a lot to see: there's a flexible pcb in there, a connector, a display controller, presumably four switches and a rubber thing to press onto these four switches. Uh yeah, so not a lot to see in there. The chip obviously has some sort of rs485 interface yeah.

So that's quite interesting. Okay, let's put that back together. Oh maybe not maybe that chip there is an rs485 interface chip because that's the connector there we've got some resistors and then that runs up to this chip. Yeah, so that's rs485, and this is the display controller, nothing else in there.

So i've just hooked this up, and it appears to be doing that calibration thing where these things change. Color says blue. Currently, on that arrow, now it's red on that arrow, and so once it's done that for a few seconds it should zero out the current measurement. Yes, it has, even though, actually we don't have the current measurement device plugged in, but that was now i've just powered this down.

So i'm just wondering actually, whether uh losing power causes this to reset itself uh interesting. What are the settings for? Oh, it's to remember the 24 amp hours, whether it's remembered the current um calibration or not. I don't know yeah, so i think it's now got that wrong, because the current shunt wasn't plugged in so i should be able to go into set come down to clear. Current okay set current to zero.

Okay, completed come out of set and yeah that zeroed out the ammeter, so that was the first look at this um dc voltage and current meter and also coulomb meter. Now, you're obviously going to see a lot more of this, because i am going to try and integrate this into my solar crypto mining system uh, particularly for when the current start getting quite large. This is going to be very useful for measuring those higher currents. Now, what about purchasing this device? I talked to the manufacturers about a purchase link and they said yes they've.

Given me a link which is ship24.com zh i'll put that in the description below i've never purchased on that site before, i would imagine if you look out for this thing on aliexpress, possibly even ebay, you're likely to find it. I think it's a relatively new model, but it should become available from the more familiar purchasing sites in due course. Now. It's just thinking about whether or not this could take the place of my load controller, which switches on the load when the battery gets to a high point and switches off the load.

When the battery gets to a low point. But i don't think it can, because both the over voltage protection - it's on the previous page and under voltage protection - have timing for functions. So you can tell it to revert after so many seconds, but that's not what i want or when. If you set the time value to zero, then of course it won't revert to switching the relay back on unless you press the ok button.

So it would require a manual intervention, so this will certainly be useful for measuring current um voltage and also accumulated kilowatt hours watt hours coulombs, which are of course, what seconds i believe they are no amp seconds. Coulombs. Aren't they what seconds are joules? That's right, but i will still need my load controller for the switching functions, so i may not end up using the relay switching part of this. It may just simply be a monitoring device, but anyway that's a first look at this uh kg kg 140, f dc voltage and current meter or coulomb meter from the hangzhou juncts instruments.

Company limited big thanks to them for sending this to me, cheerio.