Good morning, all lipo packs, so lithium ion battery packs, i think they're, all for cell. Yes, these are typically used for radio control quadcopters, that sort of thing uh. The chemistry is almost certainly nmc, nickel, manganese cobalt or some such they're, not lithium-ion phosphate. Now i haven't looked at these for several years could be three years.

I can't remember, but i thought i'd dig them out and just see what was what so, let's put them on some sort of battery tester here's the little uh bg8s battery tester. I wonder if we can just do it with the main connector yeah. That's fine, we're not getting cell voltages, but we are getting a pack voltage which is 15.69 fine. Let's put this one on now: i've not pushed the plug all the way in and there's a good reason for that.

Oh that was a bit lower 13.64 and let's try this one. Oh nothing at all dead. So here's the story, this one, which is a regular lipo pack, absolutely fine, had some charge in it. I charged it up.

I used it these two, which are intelligent batteries with the third wire running up to the xt60, and it actually has a third connector, both completely flat zero volts, nothing well a few tens of millivolts. Perhaps so this one, i recharged very carefully and gingerly, of course, as you would this one i haven't done yet so today, in this video, i thought i'd charge this battery back up from zero volts and show you the processes. I used right. First things.

First, let's get a multimeter on the battery pack and see how many volts we actually have make sure this is definitely not in the 10 amp setting, although this is completely flat, so it wouldn't really do anything. Okay, volts dc plug this in sorry about the fact that i'm using two black wires, but this is the only one i can find with the s on which means i've soldered it, because these are notoriously awful uh when they're just crimped. So there we are 96 millivolts across the whole pack. That's all four cells, 25 millivolts per cell.

So now we need to start charging this battery pack, but i want to do it incredibly gingerly and i'm going to do it inside um to start with, because there's no energy in here, if i put a nail through there now nothing would happen and until we Get to several volts there just isn't enough energy in here to do any real harm. So let's get that started and it's actually incredibly easy. You just switch this to diode there we are and it starts charging, and that's because when your multimeter is on diode test, it puts a little bit of current around the circuit in order to measure the forward voltage of the diode. Well, that little bit of current flowing is charging the battery pack.

So i'm going to leave that running for a bit. I don't think it'll get very high in voltage. I think on the other pack i got to about a volt and then it slowed down to a crawl. So i had to switch to another charging technique, but at least it charges this incredibly slowly and so there's no danger of anything nasty happening right.

We're just coming up to one volt: now, that's one volt across the whole pack, so it's only quarter of a volt per cell, so i'm still perfectly okay being indoors because there's just not enough energy in here to do any kind of damage. But now we need to do the most important thing of all during this process, and that is to check that all four of these cells are coming up in voltage. Because if there's a dendrite in any one of these, then that would tend to hold the voltage of that cell at zero or close to zero. So i'm going to check all four cells on the second multimeter by going across them like so um.

What are we looking for about 250 millivolts per cell, so that's 200, and something that one is 250, that one is 280 and that one is 260, so it looks like they're all coming up cell one looked a bit odd. Let's do that one again, i'm not sure i'm getting a very good connection on there am i okay. We got 220 on there, so i'm not too concerned now. This is slowing down, and this is not a way to um, actually start charging this battery, i'm going to need something else.

It would take. I'm not sure this would actually go above about two volts, because of course, it's only intended to measure diode forward voltage drop. So we need to switch to another way of lifting the voltage of this up more quickly, right, we're up to 1.1 volts. I've switched the uh second black wire for a green one, so green.

It now denotes positive yeah. I know it's still, not very good. Is it right next step, i'm going to use this 12 volt sealed lead acid battery and somewhere i have a resistor. Now this one is quite a high value - it's 4k 7, but i think that'll be good to start with, so i'm just going to tuck that inside there, if i can get it in right.

So, let's move negative of the battery to negative of the battery, like that positive of the lipo will go to the other side of this 4k seven. But before i do that, i just want to get some wires in here so that i can see. What's going on in terms of voltage, so let's hook that up to the negative i'll need another wire um. I think this white one is sort of working there's no s on it.

I write s on it when i solder them and they're really rubbish when they're not soldered, okay, so the multimeter is hooked up to the lead acid battery, we're seeing the voltage of the lead acid battery, which is 12.9 volts. Let's put the positive of the lipo. Now, on the um, far end of the 4k 7 resistor and up we go with a little more pace. Um we'll see how far this goes.

I've got another resistor so that when this slows down, i'm going to switch to this 680 ohm resistor, which should pep things up a bit, but this should take us up to uh. Oh, i don't know two three volts so heading up to two volts and once again the most important thing to check now is that these cells are all coming up in voltage because we don't want any cells which look like they might have been compromised in the Discharge to zero volts, so that's 0.4, that's 0.4, that's 0.49 and that one is 0.47, so they're all similar voltages. So my guess is that the cells are all good. We just need to keep lifting the voltage of this pack up until it's going to be recognized by some sort of commercial lipo charger right.

This is slowed right down at 1.888, volts with the 4k 7 resistor, which is a very low value. So now i'm going to switch in the 680 ohms, so 680 ohm resistor in there. Oh, that connection is not terribly good. Once again, um i'm looking at the lead acid battery voltage.

Okay, let's put the lipo on that, should push it up a bit more quickly. Yeah there it goes that's going to hit three volts fairly quickly. Now, if we can get that to four volts, that is at least one volt per cell might need to go further than that for a lithium-ion battery charger to see it. But let's just see how far it goes with the 680 ohm resistor uh one point about using this 12 volt lead acid battery.

The final charge voltage of a four cell lipo is something like 16 point something well, it's 16.8, isn't it 4.2 volts per cell? So, even if i left this indefinitely um there's no way, i could get this pack up to a state of charge. That's going to be problematic, uh or or stress the battery in any way. So 12 volts is probably quite a good choice to bring a four cell pack back up three and a half volts. Let's see if we can get it up to four: that's one volt per cell right up to four volts now now i could, at this point um again measure the cell voltages, but i'm going to see if i can connect it up to a commercial battery charger.

This little isdt again it was a banggood um. Well freebie. Let's say i did a review on it many years ago, um, so i'm going to sweep all this away. I don't need the dvm now, because this thing has the ability to measure each cell voltage and i'm going to drive this from that.

Other lipo, which um didn't go entirely flat, and so that can be my source which goes in there and then my battery to be charged goes in there. Let's set all that up right, let's plug in the supply battery, which is that one, this thing powers up now, let's plug in the battery to be charged and see if it manages it. Oh that's saying it's a one cell. Well, it would because it's very low voltage, let's plug in the balance lead, so i want 4s um charge, lipo 4.2 volts 4s, i'm going to set it to 2 amps.

It won't charge at 2 amps or anything like it initially, because it will recognize, hopefully that it do. You want to perform unbalanced task. Well, let's say yes and see what it does. Ah battery connection exception.

Yes, all right think no! You can't press that. So it's still not um at a high enough voltage for this thing to charge it. I've got another one similar to this. Let's try that let's try this q6 lighting.

If it won't do it, then of course we'll have to go back to um. I wonder if we could charge this unbalanced, actually, we'll have to go back to the other one uh battery voltage. Oh that's! Coming up! I don't know whether that means it's charging, but anyway, let's see what this is charge. Lipo 4.24 s current 0.1.

Well, these things normally have um a detection if the battery is low, let's just start that without balance, yes abnormal battery connection. Yes, thank you. So it's not going to do it because the voltage of this isn't high enough, but that's interesting because it was creeping up. Wasn't it when i first plugged it in so, is it doing a thing where it's trying to lift its voltage? I don't know well clearly we're not quite ready to put this on a commercial battery charger, yet they seem to be getting cross um.

I didn't try all sorts of various combinations of pretending. It was a a smaller number of cells or something like that. I could have tried that uh yeah there's all sorts of combinations. I could try, but i think i'll just push it a bit further on the lead acid set up and then have another go on one of these isdds.

In fact, i've decided to have another go with this, i'm going to tell it that it's a lipo 2s, because it should recognize that, but i will put the current right down to 100 milliamps. This thing is on there just because this will work just on the balance charge lead. So that's going to be my check that the individual cell voltages are all right. So will this work at 0.1 amps? 2S? Let's try it's going to be unbalanced! Yes, 100! Milliamps! Oh and it's doing it, there goes 100 milliamps.

Now we've got the output voltage here. 4.3. 4.4. That's now booted up because it's getting enough volts, although it's a bit erratic at the moment, but we should, when that boots up properly get some cell voltages uh.

4.5. I might need to raise the current a bit actually because i think that's holding it down a bit. So let's go for current 0.2 amps see if it'll do that 4.6 here, that's stabilized, so is it going to we've got a flashing red naught volts thing there. That must just mean that it's below the operating voltage of this device we've got 4.7 volts on the pack now uh charging at 100 milliamps i'll just leave that for a while.

I'm not concerned that this pack is going to burst into flames at this stage. I'm really waiting for this thing, which always the display times out on this. It's really irritating uh to give me some cell voltages, but it presumably won't do that until it's seeing enough voltage that it's happy that it's a lithium type battery 5.6 volts across the whole pack right by unplugging this and plugging it back in a couple of times. It's now showing voltages.

Can you see that just about they're, all red, because they're all low but they're, all 1.8 1.7 cell one - is a bit higher than the others, but this device can balance as well, but i really just want to get to a situation. Stop switching off! No! I don't want that back to a situation where um i can plug the balance lead into this charger, and this charger can do everything on its own. I think we need to go a bit further than 7.4 volts, though um. This is now up at 0.2 amps, so i could probably bring that back down to 0.1 and do this at the slowest possible rate, which is less likely to cause trouble now.

Having set this to a 2s, that's not going to go much beyond 8 volts 8.4. Will be the top, so i should probably stop it and tell it now that it's a 3s uh still 0.1 amps start that, yes, i want to do it unbalanced. It's saying that, because the balance leads not plugged into this device uh, the pack is now down to 4.5 volts yeah. I think this is putting a heavy load on it, um when it's constantly rebooting.

So, let's take that off for a minute get this back up to a suitable voltage. It had got up to eight volts hadn't it. So let's get it back up to eight volts and then plug that in and see where we go from there. So i'm not going to leave this for a while.

I can see that all the cell voltages are coming up. There are no obvious problematic cells. This is currently set to 3s. I think it doesn't really matter it's on 100 milliamps.

So it's going to take a long time i'll come back when we're ready to start bumping up the current and charge this like a proper lipo. Now, even though i've set this thing to 0.5 amps half an amp, it doesn't actually run at half an amp because it realizes that the cell pack is very low. This is now set to a 4s, so that's the proper setting for this pack, so it will continue to push 100 milliamps into there until it recognizes that the pack voltage is up to well, i think 3 volts per cell would be realistic. So this needs to be about 12 volts.

I think, and then this should then rise up to the higher current and we start charging this at the proper rate, at which point i suppose i might take this outside, so that if it does burst into flames, it doesn't do it in my house right. I've managed to find a setting on here, which is the low voltage alarm, and i've set that to 2.5, which would be more appropriate for say, lithium-ion phosphate. I know this isn't an iron phosphate, but i just got fed up with the alarm sound so 2.5. On that back, and so these the first cell, which does seem to be leaping ahead, a bit, is over 2.5, that's not showing in red the other three are still under 2.5, so they're showing in red uh.

So that's probably better for this, because i really want this thing to not be in an alarm state. Uh. 9.6 volts. This is still running at 0.1, even though i think it's set for 0.5.

Let's have a quick look. Yes, it is set for 0.5. So let's go back and just leave it and wait for this to get up to about 12 volts, actually because i'm just bored and want things to do perhaps i'll, take that off there and put this into the actual charger. Now: okay, there's! No! It's not a touch screen julian, so you've got to press that um okay.

So now, let's just do a regular charged lipo 4.24 s, half an amp start. It can now see the voltages on the balance charge lead, and so yes, it's running at so i don't need this thing anymore. It's running at um, a 100 milliamp current, even though i've asked it for a half amp charge and of course it will stay at that. Until it sees some sensible voltages on all of the cells, then it will rise up to half an amp i'll.

Take it outside and then it will balance at the top and bring all the cells to the same voltage. One would hope just got some interesting screens on here. We've got the cell voltages there. Interestingly, it's saying that the pack is zero percent charged, presumably because uh at three volts per cell, it assumes that's about the minimum.

If i scroll the wheel, we've got the internal resistances, it's not calculating those. Yet until the cell voltages are at something it can work with um, it's showing me that the input pack, this one is at 15.5 volts. That's still got some juice in it. Uh the output pack.

This one is now at 10 volt. So two and a half volts per cell uh, two watts - is the power coming in and only one watt going out. Yes, i suppose this could be burning one more. It's actually quite warm so yeah.

It could be eating up one watt within its own circuitry uh. It's losing quite a bit as heat, but uh yeah, some useful information on there still at 100. Milliamps, though um i found this neat little uh cell, monitor thing, which i put on the source pack just to keep an eye on it. All the cells on there are exactly the same voltage 3.87, but we're now at the point where this is uh: 3.1 on cell 1, 3.02 on these two cells and just 2.97 on cell three.

So i think when that gets to three volts, i'm guessing! That's the point at which this will ramp the current up to start doing a proper charge. It's still saying zero percent once it does start running at the higher charge rate. I am going to ship this all outside and i've got a glass table out in the on the patio. So i'll put it on that, just because the amount of energy in here is now starting to become significant.

I mean it doesn't show any signs of problems and, although you can't see it very well, uh the cell voltages are all reasonably imbalanced cell. One seems to have gone ahead of the others a little bit but um. That should now that it's three volts on all. Can you see that you can't really? Perhaps you can see it better there, three volts on all of the oh? Yes, that's gone to half an amp right, moving it outside right.

I've put on this uh glass table on the patio just in case there are any problems. I don't anticipate any. Can we see that? So? Yes, that's going up quite rapidly now that it's at half an amp 3.4 volts per cell. It says that the pack is at 14 state of charge.

I was just going to see whether i can find a thing to take it to 4.1 volts rather than 4.2 i'll. Have a quick look yeah here we are look. We've got lipo 4.2 and lithium. Ion 4.1, so maybe i'll set it to lithium-ion 4.1, so it doesn't go quite as high yeah.

I think i'll do that and now i'm just going to leave it here and probably forget about it and so come back when it's done so see you a bit later right, i've stopped this charge um. I don't see, there's any sense really in charging this right up to 4.1 volts. I haven't really got a use for it. The cell voltages at the moment are 3.85 or six.

Actually, still, i can't remember which one was high, but cell one is now fractionally lower than the others, but i'll just take it inside and hook it up to a bat go compatible device um just to show what bat go actually is. So this little bg8s balancer is back to go compatible. So if i plug that in now, if i only plug it in part way, it tells you the pack voltage, but it can't tell you the cell voltages, because i haven't connected the balance lead. But if i plug that in all the way that third terminal connects up - and it can now tell you that it's a charsoon battery - which it is it was made in 2017 - it's a lipo 4s, it's 1300 milliamp hours.

Yes, it is um, it can be charged at 5c discharged at 80 c. What else we got here? It tells you the number of cycles, one cycle, one alarm, one charge and one discharge, so any more information uh! Yes, it gives you actually all the cell voltages. Funnily enough to two decimal places and those voltages are being measured by the microcontroller in the battery and sent out as a digital data stream on that third pin. Now, if i connect the balance charge lead, it actually gives you the battery cell voltages to three decimal places, and now what it's doing is it's actually, this device is measuring them on the balanced charge lead.

So there is going to be a discrepancy between what you see here and what you see if you take that out and rely on the measurements coming from this battery, there are some other things you can do. You can press and hold that. I think you can go into here and you can. You can actually write into the little memory chip in here what its end voltage is now, of course, this is only relevant if you connect this to a bat, go compatible charger, but you can tell it that instead of charging to 4.2 volts, we want to charge It to i think this only goes between 4.1 and 4.2, but you could say uh charge this to 4.15 volts and if i go back then it writes that into the battery.

So if you connect this to a bat, go compatible charger, it'll charge it to 4.15 volts instead of 4.2 and uh. It does some quite clever stuff, but is back, go still a thing i mean. Are you a radio control enthusiast? Did you ever use bat to go pax? Is it still something that people are using so there we are both the smart, charsoon batgo compatible batteries are now charged and ready to use um, but i'm gon na have to keep an eye on these, because i think i read that the standby current of the Little chip in here is 50 microamps, but if you leave these for a couple of years, when you come back to them, they will be a completely flat cheerio.