Robotic Vacuum Cleaner that SUDDENLY stopped WORKING! - Can it be Repaired?

[@DEmma1972]

Great explanation of 18650 battery safety

[@EmeraldHill-vo1cs]

And lacking the important influence of the circuit board.

[@hadesmcc]

That was very interesting. Thanks for the info on the internals of the battery and how it works.

[@johnbonham7515]

Those robot vacuum cleaners are great at collecting dust, my brother bought one and after a week of use, it’s been collecting dust at the back of a closet. That thing made such a racket that trying to be at home when the thing was running was like trying to live in an airport runway. Regarding the battery, there are certain BMCs (battery management controllers) that keep count of the charge cicles, charge and discharge rates, and remaining capacity, and are programmed to deactivate the pack at certain established point. Not the case of this one, but there are battery packs that can block themself at the end of their expected life. Nice video!

[@beautifulsmall]

Your a brave man Vince, I tried making a battery pack - Once- it set on fire. BMS circuits often have charge and discharge fets so they may show volts out but wont allow changing in. Some have flash memory and can undervolt lockout so even replacing cells won't bring back to life. Some cells also have an overcurrent trip , like a bi-metalic click button but can't see that tripping in this setup (and unbranded cells) The pressure trip is another feature which seems more likley as you describe. Fascinating to see how these have failed.

[@BowsettesFury]

Today I thought my second Nintendo Switch just died. But after a few hours of deciding whether or not to throw it away and buy an OLED or not I grabbed my original Switch (confirmed needs a new MoBo) and tried the battery. And boom it spring to life. Been here for quite a while watching since before the “Switch Killer days.” 😂 I figured to heck with it and maybe I can save myself some money for once and try a small repair. Thanks Vince ❤

[@100SteveB]

I never knew that 18650's had that built in safety device. That is making me think twice about using them in my model aircraft. I switched to 18650 packs a couple of years ago because they were lighter than the equivalent lipo packs. Whilst it's great to learn of the built in safety feature I am not so sure about using battery packs in an aircraft that could just cut the power without warning. Very interesting.

[@bobahnjr]

Great info on battery internal pressure ! This old Dog just learned a new trick !

[@CLC-1000]

The robo vacuum makes a comeback. I love these videos.

[@Rage_BX]

Hello Mr. Vince, I am a really big fan of your channel, especially your tips and tricks and the Wii u and Nintendo switch tutorials. Something about how you go over stuff I can imagine it being really helpful for those who are not really familiar with these stuff, and sometimes it’s just for fun that I watch your videos as for years I have enjoyed watching this channel. One favor: Please continue to upload more stuff with the game consoles and more tutorials. -Luke

[@Coopzzz360]

I had no idea about the batteries, that’s a great safety feature!

[@pceefixer]

I think I know why the second battery failed so quickly Vince! In use the new battery you installed may have a vastly different drain rate so it's capable of putting out say 25 amps of current. When paired with cells that can only put out say 6 amp it would cause them to heat quickly. Just an opinion but I think if you replaced them with cells of the correct type - either replace ALL 4 or just get the right original cells you would not have had an immediate failure. Just my opinion! ABSOLUTELY LOVED the video - keep them coming!

[@TylerDurden-pk5km]

That is not how current works, the weakest cell (highest internal resistance) in a series string determines the maximum current for the string. Nevertheless: Replacing all would have helped, but he only has very expensive cells and you can buy the whole pack for under 20EUR from China.

[@zynaps666]

As a constant vaper I would never mix brands. The safest thing to do would be replace all 4 with molicel P28A. Cheaper than putting out a house fire.

[@shaunbogle9162]

Those BMS/Charger boards like to go bad often. I bought a variety of the cheap BMS/charge boards in 5 or 10 packs from Amazon. They are so cheap and I have fixed quite a few things at the house using those boards. Have fun and keep on fixing stuff.

[@TheJensenInterceptor]

They say, wait for the END, definitely worth it in the END. END was the best of any video yet from VINCE. Cheers - Especially after England just won again !!!

[@mark-andrews]

Spain won, yesterday evening!

[@tonibonbonii]

Blue hoodie man doing magic again absolutely love it ❤️

[@Dmitrytln]

Letter C means physical discharge rate: if battery capacitance is 2600mAh, maximum current during short circuit will be 7800mA. CID is required only in United States. You hadn't checked semiconductors on board, unbalanced cells could be result of improper BMS work. Opened cells are common problem of Makita tools.

[@TylerDurden-pk5km]

The C rate is not the short circuit current - it is the maximum safe operating current. The short circuit current will be much higher.

[@Longplay_Games]

Interesting, I look forward to seeing you troubleshoot the charge circuit

[@Firecul]

The C rating you found is a measure of amperage the cell can be charged or discharged at. A rating of 1 on your 2500mAh cell would mean it can be charged or discharged at 2.5A. A rating of 3 would be 7.5A. Basically multiply the capacity by whatever the C is. Just watch out though as sometimes cells will have different C rates for charge vs discharge.

[@PeterHovorka]

Exactly this ☝

[@markmurphy3578]

It would be nice if you had a holder for when you needed to weld onto a cell. 3D printing would work to create something. Excellent video as usual

[@beavis6363]

Good stuff. It's always worth while chilling with Vince for a bit. Now I know about that pop out dimple, and vents on those cells. Good to know that information for diagnostic reasons, regarding how the cell can appear to just go flat. I felt sort of smug knowing about balanced cells and having you confirm it as proper practice. Always trying to keep up with you kids.

[@ralphj4012]

Good discovery. Use caution when welding (too high a current can punch holes in terminals). Even a quality 18650 only lasts around 200 charge cycles (given the current that the vacuum must be drawing, expect between 2 and 5 years use).

[@goku445]

highly depends how you use them. For exemple if you don't need full capacity you should never fully charge them. Also they should be stored at around 60% cap.

[@LucasLane]

I have one of these in my house that I picked up off the street when I used to be a courier. Took it apart and appeared to have some liquid damage. Turns on but complains the battery is low even when a fully charged battery is inserted. You interested? Happy to post to you rather than it sitting in my cupboard

[@thegees]

always love a bit of vince spot welding

[@rbuschy]

It has been in my head for eons that you never mix cells, even of the same type. And from what I've seen in the past. Most repairs of this sort usually involve replacing every cell at the same time. So much so, that early in the vid when I saw you were only intending to replace one, I was thinking, you can do that!? Old Cell is not going to perform the same as a new cell, even with all those electronics. So to me it kinda makes sense that you'd burn out the old ones faster in that setup.

[@g.h.190]

With a proper working BMS it is no problem.

[@andymouse]

Capacity is capacity, you check the capacity and let your BMS do the trick. To be honest if you don't fully understand this technology you should leave it alone because it WILL burn your house down and maybe kill or injure someone.

[@rbuschy]

@@andymouse BMS's are far from perfect. I pulled a pillow out of an in use Laptop a couple months ago. It was a friends machine that he runs as a desktop; always plugged in. If I didn't happen to open it up to do a RAM/HDD upgrade, who knows what would have happened.

[@andymouse]

@@rbuschy I agree, my point was to really hammer home that you need to know what your doing as you clearly do :)

[@GadgetUK164]

Brilliant Vince, and great advice =D

[@Mymatevince]

Thank you so much Chris, I really appreciate the support you always give me. Legend!

[@GadgetUK164]

@@Mymatevince =D No worries, I always love the videos!!!! You're a legend!!!

[@zs1dfr]

Spot-on, Vince. Well explained!

[@vitor900000]

Vince one very important thing when dealing with batteries is to always keep 1 metal bucket half filled sand and some extra sand nearby. If a battery starts smoking / going nuclear, throw it on the sand buckets and top it up with the extra sand.

[@richardbrobeck2384]

can't wait to see more of the spot welder I might need to buy one !

[@mrjsv4935]

Interesting fault and good demonstration that new battery pack is indeed the best option.

[@danandrei96]

Great job Vince, well done as always! Funny thing I was actually looking at buying that exact same spot welder this week to build a new ebike battery, I'll keep an eye out for your video on it. Thanks!

[@docneron4933]

When LiIon cells age, tiny crystals form on the super thin insulation layer between positive and negative. It can then happen that these crystals perforate the insulation membrane, leading to internal short circuits that trigger venting and popping of the current protection. I assume all cells were aged to the point of failure and charging them sent one after another over the edge. That’s why you never replace only one cell of a pack but all of them - unless specific applications have batched cell systems like electric cars.

[@kkal1183]

Dance of the Sugar Plum Fairies in July .. Awesome !

[@logothaironsides2942]

Good fix. I have a different one but it looks almost the same so it might be something I have to deal with in the future.

[@rdpeake]

So, i suspect there are 2 issues initially - the reason you had no voltage initially was because the battery protection circuitry had dropped all the way to cause it to enter under voltage protection. This disconnects the batteries from the rest of the circuit until something external causes it to reset. When you were probing around you caused enough of voltage to overcome the protection circuit and let the battery pack turn on. Once it turned on the initial issue of the dead battery was causing the charging to not work. Another issue you may have - if 1 battery is weaker than the rest, under load it will deplete faster than the rest (or hold no charge and instantly drop to basically no load) and at that point it starts to reverse charge, which is really bad for the battery and could easily be what causes the battery to off gas and break the protection, or to actually cause the battery chemistry to go short circuit, rather than open circuit. The 19.5v or even, over charging shouldn't be an issue as i suspect the charge circuit is designed to cut off once any cell reaches 4.2v, however because the battery management system isn't a balance charger, it won't ensure all cells reach 4.2v, which will mean any cell out of load with the rest will get weaker faster, and adding a stronger cell back into the mix will actually make this issue - plus the reverse charging one - more likely to occur. If you are using a non balancing charging system, you also want to match capacity, not just voltage as the higher capacity cell will deplete its voltage slower, and mean other cells drain even lower before a "flat voltage" is shown to the vacuum - though in theory the battery management system is meant to disconnect the cells in this instance, depends on how it is wired as to when that works.

[@TheDefpom]

The protection IC (probably a DW01) detects a cell voltage for both high and low voltage conditions and disconnects the cell from the circuit.

[@xzibit1978]

Disappointed by not hearing the trademark “YES! YES! YES!” *whilst shaking fists vigorously* 😂 great video regardless

[@ovalwingnut]

Absolutely loved your "text description" of Vince doing his trademark™"we are the champions" cheer. Very realistic. CAPS, Bold.. it's got it all! You might be in the running for a guest host spot. Seriously.. You RoCk! Cheers from So.Ca.USA 3rd House On the Left (call before stopping by)

[@xzibit1978]

@@ovalwingnut 😂😂 I’ll be sure to

[@kareno8634]

NOTE: Anything regarding *need to 'Shake Fist'* about, holds Great meaning.

[@ovalwingnut]

@@kareno8634 That was deep

[@telecomsuk]

Great video. A while ago there was a video about gopro batteries trying to be repaired, it seems that the BMS had a protection circuit that reset when the voltage was removed.. The BMS simply decided it wasn’t going to work anymore, I saw a repair of a car start pack, that had similar BMS protection circuit.. Basically it seems it could mean, new batteries means new BMS on some devices.

[@AdrianNelson1507]

I liked your battery diagram 👍🏻

[@davesmith7671]

Are you going to leave a link by any chance for the spot welder ?

[@APSuk2]

I am interested in that spot welder, looking to replace my tiny battery powered one that can only spot weld 0.15mm nickel strip, 0.20mm is just too thick for it and the welds are weak. I find to get the power setting on the spot welder right I use some scrap pieces of nickel plate of the same thickness I am going to use on the batteries. I then slowly work my way up in power until I am happy I can't tear apart the strips with my hands. You can go too high with the power and the spot welder will just blow a hole right through the Nickel strip. I found I was pressing way to hard with the probes which led to a poor spot weld, I guess that's because my spot welder has limited power and by me pressing really hard caused the connection to be to good allowing more amps to flow than my welder can deliver. I only press lightly with just enough pressure to hold the Nickel against the battery this allows me to also reduce the power level on the spot welder and still get a good weld.

[@TheBrokenPast]

Vince, the C-rate is the rate at which the battery can discharge (or charge), relative to a 1-hour time period. When I used to fly RC airplanes, I had to spend a good amount of time marrying up batteries with motors, ESCs, etc., to make sure they could probably provide the current needed to supply the draw of all the electronics on the plane. So, I spent entirely too much time comparing discharge rates, and charging rates on batteries to make sure I didn't have issues. So, for your no-name battery that had a discharge rating of 3C, that meant that for a 2600mAh battery, if it could discharge at a rate of 1C, it would take 1 hour to discharge all 2.6Ah. At a discharge rate of 3C, it could discharge it all in 1/3 of an hour, or at a rate of 7.8A. With your new Samsung 25R battery you used, looking up online, it says that it has a maximum continuous discharge rate of 20A. Converting that to a C-rating, as it's a 2500mAh battery, that means it has a discharge rate of 8C (8x2.5A = 20A). I don't know if that has any bearing on the destruction of your other batteries. I suppose it depends on the battery circuitry, and whether there's any rate limiting on the current draw that it can pull. But I suspect there might be a chance that the Samsung battery was potentially discharging at a higher current than the other 3 no-name batteries; potentially causing a heavier draw on those batteries, and ruining faster what may already have been (as you mentioned) another dying cell. Of course, that's completely speculating at this point. But, hopefully the explanation of what the C-rate is on a battery helps out!

[@vwgolffancarreviews7111]

Very interesting 🤔 that is strange to see one of the cells to go ded love the video's vince

[@wisher21uk]

Brilliant video Vince very informative didn’t know about the safety feature thanks for the lesson today, was wondering if when you shorted the cells could of that of damaged the circuit? 😊

[@jaredl2239]

Thank for for the bit at the end explaining the cid. I had no clue.

[@Msound500]

Great video like always ❤️🤩 thought this more about balance, your new cell make the bms based on it put higher voltages or amp to old ones and then pop CID

[@TheDefpom]

The protection chip, probably a DW01 will be shutting off the battery connection, because it has detected a cell is less than about 2.8V.

[@solveit1304]

I see that measure to fix behavior many times, even on your videos. This is some kind of BMS reset, when BMS is maybe in protection mode. From my experience it's almost always transistor and you induce current on gate pin, current flow and keep translator "open".

[@NikolaArsovski-r2y]

I had the same issue with the same model. And cell was OL but it was good I just needed to reset it by pushing needle under positive contact. There are holes under positive cap where you push with something sharp.

[@leoglena2812]

Good video, Vince.

[@TheDefpom]

A "C" rating is a multiplication of the rated capacity in relation to charge or discharge rates, in this instance a 1C would be 2600mA, 2C would be 5200mA, 3C would be 7800mA, 4C 10400mA etc.

[@Mymatevince]

Thanks Scott, that is a nice easy one to remember. Excellent 👍

[@mandragor85]

6:35 when you slip something metalic jumps on the board may have been a solder flake that did short someplace :)

[@zynaps666]

Vic. Seriously. Release the last ten minutes of this video as a standalone. It explains the dangers of these batteries brilliantly. These things are everwhere. That's why you can see videos of them going off like rockets if misused. Heads up to fogstar too, always trustworthy, I wouldn't buy batteries from anyone else. Great video, keep up the good work my friend.

[@89ludeawakening1]

When concerning balancing batteries in a pack, the logic board will usually self balance. The cells will charge slower until balanced and then start charging at full capacity.

[@TylerDurden-pk5km]

Measuring the battery after the protection circuit if the charge circuit is suspect is useless. Guess what the protection circuit will do if the battery goes too low - exactly, cut the voltage to the leads so that no further discharge can happen. Also: The correct charge voltage would have been 4,2V x 4 = 16,8V (max). Using 19V again could cause the protection circuit to disallow charging. The protection board on top is not directly involved in charging, that is purely done by the charger. The only thing is the protection board does it interrupting charging/discharging when the battery is used outside of its allowed parameters. The only thing that would result in defect cells that could be caused by the protection board, is when the cells are grossly out of balanced and the board would not be prematurely terminating the charging process. PS: Had the same battery - with the same issue.

[@davidk6271]

Will you go through the circuit board on top of the batteries and check them against a known good one to determine the fault?

[@jhgpsimons]

Thanks, this is realy useful information.

[@jabousan9111]

Perfect explanation ! ... Now we are going to make batteries for Ev cars and sell it by force to everyone ... Great !

[@smikee]

Loving that spot welder Vince... now what possible reason do i have to buy one... 🤔

[@chris_hertford]

I used to run a company recelling battery packs (2010-2017) we always replaced all cells as single cell replacement was a false economy. These Alibaba spot welders look great, I still have one of my old spot welders they were thousands to buy, these portable types for occasional jobs great investment.

[@steve64464]

I have reset some the cid's in the past but the procedure is particularly risky , I have cut away the positive cap to expose the part under it which is a bit like a eardrum kinda thing , you can shove it back in and the cell becomes live again but there is a risk the tool will stab through the thing and when i was charging a cell after doing so i had electrolyte leaking out the top from it so i dumped that outside , CID can also pop out if your drawing/charging too much current from it so maybe the cell you substituted for it has greater resistance or is not specked to pass that current. I was once speculating on i idea to reset the cid by placing the cell in a high pressure chamber so the air pressure would push it back in instead.

[@Tim_3100]

Great video vince

[@Karthor.]

i wonder why it outputs 19V shouldn't it be regulated to 16.8V or something like that? that's the max voltage it should have on the battery pack

[@Mymatevince]

Good point, I really don't know Karthor. Well spotted 👍

[@PollokPoochesDogWalking]

​@@MymatevinceIt's giving the battery management system just a little over 10% overhead in voltage to ensure the cells can reach their maximum capacity when charging them

[@Drone_Out]

The BMS will regulate what the cells need and can take same for how much amps it will let go through out or in. The bms could have gone in protection mode and or giving wrong pass through. I encounter this all the time in drone batteries. Look for a Texas instruments EV2400 or EV2300 and find the CAN/UART ports on the bms and connect it to your computer. its a very pricey tool and you need a subscription to use but many problems or tweaks can be done with in li-on - lipo battery packs 😊. (PS in all honesty most people should not mess with it themselves so if you feel this might encourage people to test, remove my message. Purely want to inform Vince about this tool) Kind greetings from Sweden.

[@Mymatevince]

@@Drone_Out I think your comment is very useful and will be useful to my audience. Hopefully the video and your comment makes it clear how dangerous these 18650 batteries can be, so it is staying👍Thanks for posting Drone Out👌

[@drorhaz]

I also has this issue with 3 phantom batteries but instead of buying expansive tools from texas instruments i found a github guy who published a tool to do the same thing with raspberry pie i/o pins. Not easy and not for anyone but for me it was ok. ​@@Drone_Out

[@jonathanmartin3375]

Very informative!

[@craigbourne4792]

please tell us the make and model of your spot welder.... got a cheap one and it was pants. working on a few factory returns and a few have dead cells.

[@blubbspinat9363]

I have seen a lot of cells break due to the CID. It might also be due to age and vibrations. There could be a lot of factors at play here. Also, please do not mix cells of different specs or age. I've done that many times and it never worked for longer than a few charges. Also resetting the CID is possible, yes, but whenever i tried, the cells died again soon after. And they never had good performance to begin with. I think it's got to do with air getting into the cell chemistry when the CID membrane is damaged.

[@jeffers2923]

Great video Vince can you tell us where to get the welder you used please

[@zeph1rus]

I fixed one of these recently - it was the Wall Brick PSU failing intermittently, constantly cycling over/under voltage (up to 25+ volts, down to 6). Possible something similar killed your battery pack?

[@VOLTRONDEFENDER4440]

17:48 Vince please don’t use that adapter you have it’s a Chinese dangerous charger please use a safer adapter as that dosent have a fuse!

[@davidbroadbent1470]

Next week Vince will repair the uk economy

[@njakts]

Those 10 volts probably are through some high resistance. Multimeter is showing volts, but if you would put any load on the output the voltage would drop to 0. Same with the power supply. Voltage jumped to 19 volts, but through that high resistance, there isn't any charge going in

[@TheCod3r]

Im disappointed in you, Vince. The robots are taking over, and you're assisting the uprising by fixing them 😢

[@Mymatevince]

Hahaha, I thought I'd get in early and befriend them, then hopefully they might bring me along on their uprising and reward me for my loyalty. I have no choice Phil, this KZbin game is quickly dying on me and I need the next 'thing' to bring me through the next 5-10 years. Forgive me!

[@TheCod3r]

@@Mymatevince take me with you! Haha, great answer pal, didn't expect that 😜🤣

[@scottharriswestwalesfishin639]

got this same issue with my had 2 batteries for it now going on to 3rd one. look at date on batteries mine was made in 2015 so batteries are 9 years old. but when connected to charger just stays blue but wont charge at all dies as soon as you turn it on

[@YoshMaster]

I have the same eufy, works pretty great but it falls down the stairs sometimes which is far from perfect… but at least it keeps working haha

[@Frank-Thoresen]

If balance 18650 cells or testing them you should get a smart charger for 18650 cell batteries (it supports other rechargeable battery types as well)

[@MsJOCKEB]

Result! 🥰

[@johnboy4809]

do you have a link to the spot welder

[@jaimerubenmontanvillanueva9787]

Al hacer un corto al sacar la primera batería puede q hayas fundido la otra... O quizá ya es cosa de ciclos de carga... Lo mejor sería reemplazar las 4.... Quizá no valga la pena si puedes conseguir otra batería barata.. Pero quizá si cuando ya no se pueda.

[@VVerVVurm]

I don't think the cell protection has kicked in. Most defective 18650 I have seen show 0 volts because of internal shorts. They can be charged with a charger - but get quite hot even with only 500mA charging current. The capacity is only a few mAh and they go back to 0 volt in about 1-5 hours. That is the normal failure mode of old worn out cells that I have seen so far. edit: never mind .. I rewatched the part where you check the cell and you are probably right .. 0 volts AND open on resistance check means it is disconnected

[@joshkelly4682]

The end music is making me want to watch christmas movies already

[@marcellipovsky8222]

Hehe it's Gufy :-D like Goofy. BTW are you sure that the 19V are going from the charger straight to the battery? I am not sure that the battery pack itself is charged with 19V. The battery protection chip would certainly stop the overvoltage. I do have a device like this, but more "intelligent". It can map out the rooms and move in a grid patterns. It's more effective and requires less battery juice.

[@normantalib7071]

Vince I really love your videos ❤and I really love you mate just keep posting ❤

[@brad9529]

I had a Dyson robot vacuum from Japan and it stopped working, I threw it away, I wish I knew your channel back then I'd have sent it to you. It cost au$2000

[@cypeman8037]

You say it's unusual for a cell to stop working, I hope those were throw-away words because every gadget I've ever owned has stopped working because of ONE of its batteries not working.

[@smashyrashy]

@@cypeman8037 he knows more than you though

[@robertgeorge8166]

Big Clive has videos and strip down! FYI 😊

[@Cheevey]

Aaah, same fault my mum's eufy has been showing when I visit the last 4 months!

[@ElektroTechNL]

Make you own cell with good brand Battery and more mAh last years and more time to clean 😊 new bms on ali to rebuild its really nice to make your own packs

[@matteo_z]

It's a completely unrelated fault to the one in the video. But I've seen batteries going down to 0mAh (aka, can't hold any more charge). I don't remember the name, but I've seen it on a video made by Electronic repair school, pretty sure you'll find it if you search for "0mAh" on his channel's search 31:30 maybe cell balancing? I'm not an expert in batteries, but maybe it's charging the batteries that have a lower voltage.

[@ivanrlynn]

Seems like an open circuit problem, could be internal

[@matteo_z]

@@ivanrlynn the video, i'm not going to spoiler (mainly because, remember, that there's a charging circuit in between). The one I'm talking about, no, it was actually taking charge, it was just the battery exausted due to use

[@drorhaz]

I comment now and watch later.. only 38min' i need to save it for the right moment.

[@Boogie_the_cat]

Discharge rate of "3c" explanation "C" refers to "capacity" so if your capacity is 2600 mah then 3c is equal to 3 times 2600 = 7800 milliamps = 7.8 amps. So maximum output is 7.8 amps This is how C ratings work on lithium polymer battery packs, I am being an ass and assuming it is the same for li-ion

[@ricardoiarossi]

The C rating works like this: if it’s 3C, it’s discharge capacity is 3x the battery capacity, in this case it’s 7800mah(3x2600)

[@StarlightStream]

I was very excited what kind of fault this robot vacuum may have and thought it was something with the PCB unit. Guess I was wrong.

[@ninaevans4501]

@MyMateVince There is an old saying, "Best NOT to put a patch on an old pair of trousers". Basically, other parts will fail, and you'll end up with your a..e hanging out. All being said, still a geat and informative video though. Many Thanks for sharing Wayne & Nina 🫡🫡🫡🫡🫡👍🏿👍🏿👍🏿👍🏿👍🏿😊😊😊😊😊

[@dodgydruid]

So... Mrs V's birthday pressie all sorted yes? :P :P :P

[@LOTPOR0402]

Planned obselence, maybe , like old Dyson battery packs.Not all 18650s have the safety feature

[@MikeB_UK]

Please, please! go learn about maximum safe Lipo charge voltage! Putting 19v into 4 Lipos is so wrong. Max Lipo charge voltage is 4.2v per cell, so for your 4 pack your power supply should be 16.8v MAX. You should never exceed applying 4.2v per cell - cell manufacturers warn it can end in fire. Watching this one bothered me that you may have some people copying this that just don't understand. I would bet the voltage on the vacuum charge station goes through some circuitry to lower the voltage before the battery pack, it would not have applied 19v to the pack or else there would be a lot of house fires with those units.

[@KJW648]

If the board is balancing each the batteries, why the high voltage ?

[@Pulverrostmannen]

Replacing one cell in a battery pack will never work even if you would use the same capacity and brand, all cells must be exactly matching or they will drift out of voltage when you load or charge them leading to instant failure of the other cells that will reach critical voltages due to imbalance. since batteries ages their actual capacity also changes making their properties change and when you connect the batteries in series all cells must match exactly or they will fail or ruin the function of the battery. the weakest battery will determine the capacity of the pack since it will reach it´s limiting voltages first. and when the cells have different voltages the pack will also not run at full capacity since the pack will stop charging when the first battery with the highest voltage reach the limit first and then shut down when the battery with the lowest voltage reach this limit first capping a lot of potential capacity you could use if it was balanced. I see this happen a lot on power tool batteries. after proper balancing they can run like new again.

[@markveenstra702]

Woow that red powerbank has a cell that looks like its leaking or its glue, if its not glue I would replace that as soon as possible.

[@ray73864]

I would have just cut the strip. You spent so long using tweezers and side cutters trying to remove the metal strip from that battery, and you shorted 2 together, that you would have been far better off (and safer) just cutting the strip between the 2 batteries.

[@phillangstrom8693]

i knew that second cell was bad because it was only reading 3.5v before you removed the first battery the last two may still be OK for a while if you had replaced both batteries to start with it may have actually lasted a year or more and why the cells may have failed is from internal dendrite formation shorts which caused the battery to get hotter than normal then putting it back on the charger it will continue to overheat until the vent causes it to disconnect to stop thermal runaway keeping the battery from exploding on the charger this is most likely from the high voltage fed to the battery from the charger a 14v battery should only be charged by a 16v charger at a low amp rate for 4-8 hours not a 1 hour charge that's part of the reasons why the hoverboards kept catching on fire cheap batteries and cheap management boards with a over rated charger