Shorting out a fully charged cheap lithium jump starter. (It didn't end well.)

this is a fairly common eb style jump starter pack with the lithium cells inside it and it's a type that uses the standard leads which i've ordered to take one of these apart and this was given to me by a local chap called Andy hood but a while back and used a couple of times and then it just kind of stopped working so I'm the secretary when you put it into charge when you plug a USB lead in a kind of starts trying to charge but when you press that it's kind of a hex very randomly when you press the button the side to actually activate it you can fill the button clicking and I've tried shorting it out and trying to trace it back but it's just not responding to the button at all however it's interesting a look at the circuitry now you might wonder what set of protection is in these huge protector from over current and over discharging of ourselves and the answer is none not that I can see anyway maybe the tabs will just burn off the batteries or something like that let's take a closer look so the circuit board has four connections that represents one at either end of the cell the red and black and then the blue and yellow are the intermediate connections off the series of cells in the battery and that means that it can balance the suction I was kind of expecting a balancing circuit in this but there's that I mean there is balancing circuitry is based on DW or 1s cell protection chip there's one in this side and there's toon that side and there's a lot of circuitry around them with lots of transistors and I work out what it was for and one of the thoughts that came to mind was maybe it's doing a clever trick that if you put the 5 volt supply and it's actually switching through the cells and sort of using all those transistors to actually charge the cells individually by switching them in circuit but on testing it when I plug the 5 volt in a current flows in both the red and black leads and the voltages way up there at about this a 12 volt mark and listen dr. gets warm so I think it is stepping using this inductor to step the voltage up to actually charge all the cells at once and I've guessed then that the dw1 chips the lithium protection chips are just them acting as a sort of discreet balancing circuit which in a sense I would have thought they're just used but a balancing chip like you getting the standard lithium protector packs especially since it's not cutting any significant current because all the current let's compare this is coming straight from the tabs the batteries as far as I can see we'll find out shortly if that is the case because we're going to rip this open which is probably terrible idea but that's what we do the chip on the circuit board is a gsy 305 OPA and the circuit board is extremely hard to trace through because it's shiny and black let me just set this on top of this and it's very shiny it's very just really fatiguing to actually try and yo even with a magnifying glass trying to follow the tracks back there are ten little tracks and there are lots of plated through old and it just jumps back and forwards all the time and the black color it just makes it really pop it maybe that's the design maybe that's what it's for it makes it very hard to sort of reverse engineer this I couldn't find any data on that chip which is disappointing and I'm kind of guessing that then doctor then may actually be pressed into action a second time around and to actually regulate the voltage down to the five volts but I wasn't able to test that because I hadn't be able to get that Oprah to activate and I have tried tracing back I thought maybe the switches faulty but it's just it's strange the switch to mystical in both directions seems to go to transistors I'm not sure for just using it as diodes I don't know if they're giving each component as a multiple task on it you know trying to reuse pins a lot for inputs and outputs there's our two mosfet packages there's a dual mosfet there think it's dual MOSFET and another one there and right behind the cells and that was what had me thinking that maybe they're switching the cells but it doesn't appear to be this hard very strange circuitry very dead circuitry as well so here's the interesting bit let's say I open this note another thing is this battery pack here if I open this battery pack up battery pack I'm not what my talk about diode pack because back again this is a bit that's designed to stop the alternator once the engine is started is to stop it back feeding into the lithium cell and overcharging it so if I pop this open it's very similar construction to the other one I opened except it's all on a circuit board of lots and lots of ventilation holes maybe unless these were designed to be used as plated through all three coupling heat but a single sided board no real major heatsink on the solder and I have to say I tested this and it was leaking current in both directions I get the film this is already kind of leg twisted but here's a bit we really want so let's find something to open this up I think actually so that may actually be a good option here try not just stab the lithium cell I've tested the lethim pack I basically made a small adapter based from a USB charger and then stuffed up the end because it didn't notice that the tube to outer cells on the pack were fully charging but the middle one wasn't going up to full voltage so I think this circuit is completely knackered and it's controlling that but I basically treated each cells an individual cell with this and it was able to charge them individually and test so did a full discharge and charge test and it came to 1.6 amp hour for the middle cell so lets her gingerly start slicing into this pack lots of sticky tape lots of insulation slightly freaky air where's my version that yeah I've got in handy in case this goes thermonuclear on me so I'm seeing layers of insulation here the how did even so do that onto the tab I mean it's a fairly large tab it is it's a large tablets about half an inch and between 12 about maybe about fourteen millimeters 15 millimeters wide maybe the tablets come here to this cell so it is obviously designed to deal with a lot of current and they fit loads of insulation which I'm removing which is probably terrible things over the adjacent connections in here you what's the worst could happen flames well they are a big arm there they are really big terminals and that's really fundamentally all there is the insulators and they've actually folded they've got this abs of plasticized card they've put it in between there because there's a connection the high current connection another on this side of the pack they've actually put slipped the cardboard in between these two cells here and then folded it around to the outside to protect that and likewise at the other side and that's all there is to see it really is just at beer cells just soldered together with links yeah which is kind of what I was expecting really I'm just being careful here at all to cause a little thermonuclear incident not a lot to see not a lot to see at all so I'm here that's about it really it's just three cells connected in the series with the balancing leads coming out and just the post of a negative just these hefty cables these silicone tape and initially the cables going to this connector so that when you plug in these leads in the open your basis connecting the lithium pack directly across your battery and if it did get shorted out if you literally just put the lead scale like that there's going to be nothing that you know the plaque is going to go probably it's probably going to get very very hot in me actually burst into flames on you which appears to be happening a lot likewise with the failure of these diodes in some other packs it appears that you know many of these packs are in fact just going on far when people and leave them connected or over crank their engine too long so that's quite interesting it's quite exciting so under the next step that evolution in these is going to be you do get higher quality plaques that you also get the pipes that have more protection in line instead of just diodes they have an active electronic module with relays in it and I wonder how reliable those relays are going to be given that they're dealing with currents of literally hundreds of amps particularly under fault conditions of particular if someone connects that leads the wrong way down because the the diode is not going to help there you're still going to have effectively two batteries connected in series and shorted out and so that should be interests or will it develop or is this pretty much it because this is the cheapest way to do it just these super high current packs and interesting well worth taking to bits so really that just leaves the question for us what would actually happen if this gets shorted out so I've fully charged this up to the hilt actually I've taken to a four point three volts per cell which is a bit not it and I've made a special test load a test load that looks suspiciously like a bit of 15 millimeter copper pipe and I've spaced a couple of tap off points I've soldered onto this just the right distance I can get these clamps on and by measuring the voltage across this I have already calibrated in the bench supply and know that just bash your luck it came out nice round figure it's 110 microvolts per amp and attest that one amp 3 amps and 5 amps very consistent results very good and a tester I use the higher resolution meeting the normal I'm using this a mchale ST - nein nein - nein and this has the advantage of bow better accuracy and it's also got a maximum logging function as well so am what I'm going to do is a put these leads across here and monitor when I actually plug this into the power supply what sort of a voltage down here which will indicate the current flowing see for instance if it was 100 amps that would be 11 maker of the 11 millivolts I think so I'm yeah so that'll be interesting to see but I'm not going to do that at my bench because that would be extremely foolish I'm going to do it outdoors so am yeah let's go outdoors and do the test ok let's begin the experiment whoo so looking much current at oh why is that have I just blew in there something blew it that's intriguing something has just blown like a fuse okay in the previous test of this the diode pack blew open circuits let's try it again with a different diet pack Moo oh that's that's a good amount current well that's a bit 160 amps though yeah the battery packs swelling it wasn't that dramatic is that just tweeted old energy yes don't about don't about oh yeah the currents really plummeted well to be fair it didn't burst into flames I can see smoke and I can smell that characteristic smell of lithium packs sad lithium packs so I'm okay let's do an autopsy on what's a happened oh okay it's back to bench for an autopsy in the first thing I'm going to look at is the diode clack that field because I get the feeling that because this was printed circuit board based there's a very good chance that printed circuit board track has ballooned like a fuse so let's get this open her eyes it open with the spudger that quite like the way that puffed up hooker has it blowing yes I think it has blew it yes it has Blouin can you see that a sort of outline there that has just basically bloomed like a fuse I'm not sure if they intended to blue like a fuse but it has done that hey what about the diodes of the remained active one moment I'll just bring the metering now having said that these ones are a bit gob daenerys so it doesn't really matter yeah still gob okay the other pack survived even though that did you notice the kind peaked at 500 amps initially so if I prepare this lead in here and this one in here it shows that super low Ford voltage that we measured before and if I swap the leaves around it shows proper diode characteristics so that's a impressive that despite the surge of 500 amps as long said Alan let me think each of those ad diodes was rated about 8 amps was it a I'm trying to remember try remember what those died of packages were rated and was it ten amps per doubt so - oh it was a total of eighty but therefore with potentially at peak current of best part V hundred amps in this instance it only saw about five hundred hundred amps very briefly and the reason it only saw that current very briefly just long enough to blow this track like a fuse is because one of the cells not all of the cells 1 2 3 the top one is the one actually filled and it's obviously limited the current in doing so and the voltage measured across the snow is low it's about one point six volts but the other two cells are just as flat slightly bent partly because this is puffed up they are still measuring over four volts suggesting you know not that much energy was dissipated overall before this one decided to sacrifice itself to save the others and the temptation is to look a bit closer at this I really should have got love shouldn't I'm not sure should be opening this plaque and given that it may still have quite a lot of energy left but then how it's never stopped me before that's why I am so foolish oh it's slitting it slitting the the lithium pack with the knife doesn't strike me as being clever I'll ER but then again hey that kind of sums me up really recklessly foolish so let's get some snips into this that is one thick cable it doesn't look very coppery I wonder if that steel orator aluminium I'm guessing it's probably aluminium aluminium hey what can I cut that with snips cut the tip away here defuse the pack so I need to cut that one as a ball well guys just like defusing a bomb actually feels like defusing a bomb as well mainly because it is a literally theeban bomb because when these things go up they really go up and having already demonstrated that can easily put out 500 amps that's quite impressive let's try and cut that there I'll let you know if it gets very hot just look around for my explosion - Tim pie - eh I've spotted my explosion Tim pie - it's not getting hot I'm going to go and get my gloves one moment yeah ISO gloves is probably a good idea I don't think these gloves are flea resistant but that's okay oh right that's neon looking like a tattoo artist again let's take a closer look at this pack and see if we can see what field this may go thermonuclear again you have Irish Andy yep that's okay let's open this pack I'm thinking I'm a can really cut at that end and this end is pretty close to where all the chemicals are inside what how much energy is still stored in this although it's voltage has gone low I think it's probably still holding lots of surprises and as it's already demonstrated that it can put out 500 amps under pressure that makes it just so much more exciting mmm I'm wondering if it's going to show any characteristics any sort of damage that here no it's not going hot time just check it Oh why'd I do this it's so foolish but I just keep doing anyway I can see the liquid under there there Elektra I can smell the electrolyte you get kids sir yeah I should have actually shorted this out first but not to worry I didn't at the end of the test that was only showing a few amps anywhere though a few apps is still quite a lot of amps now that's that kind of safe rate let's unravel at least some of this that lovely smell that these MIG probably not good for you but hey I want to remind you again these will actually contain much than we have real lithium but this will change color rapidly separate separate plates its Lords of separate plates that's how they're getting the higher current Wow it's not just the usual role it's a little bit of warmth I'm feeling I think it is a little bit of warmth I'm feeling that's okay so this is a completely different construction it's zigzagged backwards and forwards with alternate polarity plates the copper base one and I think there's the other one aluminium bitched with it air oxides on it that's intriguing and because it's puffed up of course instead of being all compacted together in a vacuum coordinate compress it tightly that as effectively medical high resistance so theoretically if I was to well squeeze that down hold on let's say try let's get some to clip onto these leads here so let's get my little dinky meter I could have a meter in with that I think plants eater but let's use this one at 20 volt DC let's clip on to a chi remember which is positive and which is negative which is a that doesn't really matter anyway so go on to there and I'll go on to there it's showing about two volts what if I squeeze it the voltage is going up this still is fully charged but it's just puffed up oh that's a bit scary so M yeah that's interesting that the failure mode has been to vent it's gone high resistance and effectively shorted you know it's basically saved the day by sacrificing itself by going high resistance and limiting that current because all the plates have separated that is very interesting did particularly the zigzag construction which means of course that each of these plates then instead of relying on a continuous film it's got much lower impedance because I each one of these is in parallel it's like loads and loads of individual tiny cells in parallel inside that is very intriguing very interesting indeed is that we cover just about everything I think it is that also means that these are probably because they're not puffed up all the slight malformed but I don't think that's an issue these buff probably survived a little having passed 500 amps before they're not sure how happy they will be but yeah interesting stuff bonus extra footage will I never learn no I won't hey I separated some of these plates I separated all the copper ones into one pile and a separated all that I think is our mini ones into the other pile the other pole and I thought well that's probably quite safe because well what could happen if the simple arty the copper ones just just erupted in flames and smoke that was quite exciting yeah really unexpected as well so I know maybe I'll just not sort the rest into that same pile and I'll keep these ones well away from each other shall I

Channel: bigclivedotcom

Views: 747,207

Rating: 4.7677588 out of 5

Keywords: YouTube Editor, Lithium, jump, starter, start, booster, boost, USB, LED, short, circuit, test, fail, swollen, puffed, lipo, overload, hot, swelling, 500A, car, truck, vehicle, pack

Id: 0tGK1nqXr28

Length: 23min 36sec (1416 seconds)

Published: Thu May 25 2017