Nice vid Mr.Clive. Fun fact: You can tell if a number is divisible by 3 if the sum of the individual digits is. eg 543. 5+4+3=12. It is divisible.

Actually the one that reaches the high cutoff voltage first is likely the lowest capacity one, and they will all reach the low cutoff voltage at roughly the same time because even though one might only be charged to a lower voltage it would still contain the same capacity.

Yay!! ... A relaxing Sunday big clive video! Happy days!

I don't usually post but -thanks BC for your content, it's taught me a lot, thank you buddy.

Since we grow ever closer to the permanent move from our sticks and bricks home in South Dakota, where the coyote's howel, the snow piles up so high that cars are found by the radio aerials on their roofs, and the winters so harsh to freeze animals where they stand on the prairies, into our 36 foot Class A Motor Home, which we have used for the past 3 winters to escape to Sunny Arizona, where it is always warm and sunny, well except when it isn't. I have been planning on more 12 volt supplies for the toys that I build using Arduino's and ESP8266's I have all the parts necessary, as well as many recovered Lipo cells that I have torn from old laptop batteries, old tablets, and so forth. I have some circuit boards that supposedly regulate the cells so as to charge them properly. I currently have two built, one with a step up power supply, and another with a step down. Both work wonderfully, and I have equipped them with those cheap power displays so I know pretty much what they are putting out at the terminals, but they are rather large and bulky, I have them housed in white plastic boxes with clear lids so I can see the display through the top, and drilled holes to access the rheostats to regulate the power. But I really want one like you have covered here. I believe I have plenty of parts to build one,however I never did build my 3d printer, so I will have to mount it all in wood, or worse yet steel cut from old power supplies out of ancient computers. So at long last, I must end my run on sentence with an expression of thanks for covering this device, you see in order to be able to make our transition from house to RV, I must MUST absolutely MUST stop buying crap from China, don't believe me, just ask my wife of 48 years and she will let you know in no uncertain terms that I am NOT allowed to even THINK of EBAY this summer, lest I find myself grounded in our old house here in South Dakota and suffer through another year of cold, wind and excessive snowfall, and man I just cannot take that shit an more. After 67 years of snow in the winters, only interrupted by a few years living in Texas, a year in Nam I find the very thought of shoveling one more scoop of snow revolts me, and makes my heart beat like it may be the last of such abuse. So thanks a million for showing me the make up of this one, I fully intend on building one, what I have in mind is to use wood to build a box that will appear to be a miniature 12 volt battery with the caps and all, perhaps even paint it black, where the posts should be will be the banana plugs, and perhaps I shall have the caps light up when power is turned on. I will use a power brick that used to power my old router before it gave up the ghosts this spring for charging it, and will have a flip door where the display hides so I can check the condition of my home built 12 volt cell. I am even considering making it with more flat cells so I can have enough amps there to power my Ham Radio.

I will not lie. I was slightly (more than slightly) hoping that gang of angry-as-hell envelope cells would have gone thermonuclear. I sort of chanted in my head ala Andy (photonic) style "I'm not avin' it!! Flames!! I want FLAMES!!! Crank it RIGHT UP!!" Side note, I miss Andy and his old self.

I found this exact same arrangement inside the first generation Mini-rig portable speaker. Interestingly the mini-rig charges from 5v and uses a boost converter to charge the 3 cell LiPo pack.

I recently came across a technology I haven't seen before. It's a "powerline" internet adapter. It's basically a box that you plug into a power outlet and the box has an Ethernet cable going in. It actually creates an internet connection over the power network in your house so by just by plugging another box into an outlet you get a hard line internet connection. Would be interesting to see inside one.

Ah yes, the classic J3-Smudge transistor

I love it when you bring out the explosion containment pie tin

jehugarcia said in a video, that after running he's electric converted Samba, with 18650s from old laptop batteries, and only bulk charging them (cut of at the max voltage for the series, ie: 12.6v), as long as all the cells have been tested and shown similar capacity between them and no self discharge after a charge while sitting for a few days (no internal shorts), they've shown very little imbalance between the cells.

"...J - 3 - Smudge. I think that's a standard transistor..." LOL

I just recently bought a very similar one off of eBay from a company that makes them called talent cell

The best I’ve found for a 6# pack I made was a BMS that would monitor the cells and disconnect them whenever any was outside it’s operating range, and a balancing module which would stick a 40 (I think?) ohms resistor across the cells that went over 4.2 Is there any module to be bought that does what clive showed, with diverting all the current and balancing the cells in a non-wasteful way ?

The next time you have got one of those construction lights, take a look into its battery-pack. The one in mine is constructed similar to this one: 2 cells in series, each with its own protection circuit on a common board but no balancing.

brilliant video!

With the psu since the light lit when it was plugged into the power bank and not the wall indicates to me that you would get a nasty shock if you bridged the two bottom prongs

In the early days of RC lipos a very good make didn't have balance leads. So after a few years of use i fitted balance leads and all 3 cells were the same voltage

Ultimately balancing is about performance, not safety (assuming your individual cell protection exists and works). I think realistically that especially if you only have a few cells, balancing is probably well into diminishing returns territory, assuming of course that the cells were well balanced and matched for capacity to start with. If one cell gets out of balance so far that it's going to be a significant benefit to balance then that cell is probably knocking on death's door anyway, all the balancing in the world isn't going to help a pack if one of it's cells is dying. Balancing adds a fair amount of complexity, even most of the cheap balancing boards, where they just connect a small load across high cells to bring them back down, that's a fair old accumulation of components. The only thing I would really like to see is for the DW01 to have a just slightly lower high voltage cut off 4.25 or even 4.35 (4.3+-/0.05 tolerance for the DW01+G and you never know what you'll get from China) is just a bit high for my liking, actually I'd like a DW01 (or workalike) with a 4.1v cut off.

I feel like it may be prudent to get some type of lid for your explosion containing pie dish :)

Most of the "balancing" lithium-ion battery pack chargers don't do that "bypassing" trick you mentioned. I wish they did... They tend to charge the serially connected cells directly from both ends and check the individual cell voltages while doing so. When one of the cells reach above the set voltage, it is then slowly discharged by applying a resistance on to it thru a mosfet, keeping the cell voltage at the set level while waiting for the other cells to keep up. I never understood this approach, it is a waste of energy and it reduces the battery life significantly since it constantly cycles the cells. Not to mention it takes more time to charge the pack this way since some of the energy that put in is converted to heat by the discharging mosfets.

In work we have some batterys that are 24v 10Ah. They contain 28 18650 cells ( 7s4p ) and they have NO Balancing or protection. The carger for the packs is a 10A charger.. Things can go really bad :)

how about a follow up video, where you show us how to make a charge curcuit with proper balancing to fix these cheap power banks.

we love you clive

You said that balance charging would bypass the cell when it got to it's full voltage. That's interesting - I've never seen a circuit like that. All balancing circuits I've seen actively discharge the highest cell to bring it's charge down in line with the rest. Wouldn't it be a very complicated circuit if it were to bypass a battery and still maintain the correct voltage across the remaining cells?

damn, i actually have this power pack, good to know.

It has one of the micro small 1 amp max charge controller. I have some of those, but I purchased some that can handle 3 amps rather than 1. I blew one of the 1 amp boards.

FWIW (I imagine big Clive knows this) J3Y seems to be a pretty common marking on cheapo surface mount NPN transistors, so that would be a very plausible auto-complete for the flux blob.

I had thought about what would happen if you did that before. I think if you added diodes parallel to each protected cell so the current can bypass them if they go into overdischarge protection the thing would get rebalance if you discharge it fully and then recharge it.

Pretty lame to not have any balancing especially the boards are so cheap, but at least each cell had protection. I'd put a 3S 4 pin JST connector on them and use a lipo charger occasionally just to knock them back into sync.

They were probably saying it's going to be a 4800mAH equivalent if used as a 5v power supply. Buck converters step down voltage and output lower voltage at higher current with high efficiency, so you still put most of the energy from the battery to the load regardless. It's just that the battery is discharged at much lower current than if it was a regular 3.7v pack of 3 cells in parallel with a boost circuit.

Fooool Bridge rectifier

the capacity of the cells and the space in the case alludes to that that sticker might be referring to a version with full size cells

Interesting. My brother bought one of those, hoping they did something better than this, as he paid a fair price. But no. Also, one of the cut-off circuit chips was broken and (also) gave a terrible ripple, which worked horribly bad on what he wanted to use it for. Nice fix for it: on ebay or aliexpress you van buy charge balance circuits for around $2.

can you check one of those xiaomi powerbanks the thin ones with 10.000 mah and quickcharge? would be interesting

Pretty interesting device

3:07 (Chuckles) I’m in danger!

Thanks for sharing 😀👍

Is there a diode on the protection circuit so you can still use it when one cell is empty? That would allow balancing during discharge.

Can you give us a tour of your shop? Always like those types of videos. This one was cool too though

I have actually noticed a slight trend with DW-01 and dual mosfet protection modules upon cutoff in series with other cells on discharge they tend to act like a reverse bias diode at a few percent of their max current allowance so if a pack like this was, say, used on a short LED strip(the likely intended use case) it would dim down to pack-1 cell voltage(6-8.4v) and keep chugging along as long as the current remained under about 10% of the module limit still not ideal(I would slap a cheap Schottky 10-15a reverse bias in parallel with each cell ) then use this on a voltage variant tolerant system like the USB buck port actually with the diodes this pack would be fairly ideal for an "always on" usb port possibly even just using a 13v input with a diode and letting it stay plugged in forever and using the usb to power something like a small network switch that takes 5v power goes out and you keep your basic access point/switch going without a fully AC UPS device heck even the ~12v port would do that well as most "12v" network gear takes in 12v but then instantly bucks down to 5v or less and fuck my worn laptop keyboard the K key needs to be jabbed so hard to register

So batteries that have their protective board if you were to take 3 lipos like that and not run them in parallel and you ran them in series would it be okay to charge them without a balance lead or a balance board set up? because they all have their own protection board or would you still run into the same problem with them just charging at different rates and getting different voltage? I was just curious because I was looking to put a bigger battery in something, its just a 3.7 lipo but I want more mAh and I didn't know if it was okay to do that or if I needed to figure out how to make some kind of balance charger board or buy something that does that. thanks for the great videos and the awesome content! I love your stuff so much, you're so knowledgeable and I've learned so much from you! keep up the great work!

Do you think you could make an extremely basic load balancer using simply a diode across each cell, working on the logic that they will all have a similar efficiency of charge/discharge and if you allowed a cell to bypass itself when it's low voltage protection circuit kicked in it would reset everything when they all discharged?

Even if the batteries are made to be fully matched at the factory, they will inevitably vary with use due to external factors. That's why I think that balancing is major important. Laptop batteries do use this technique but they connect each two cells in parallel without any means to disconnect any of them in case of failure. Sad but it happens.

The cells will 'drift' over time due to different internal resistances of the cells (ESPECIALLY since they are not a brand name cells manufactured with higher consistency,) and resistance within the soldering connections and slight variations within the protection circuits themselves. When we use 18650 cells in series for high powered flashlights for eg, IDEALLY, we use cells with the same internal resistance (not much of a problem with Sanyo, Panasonic, etc) and charge them to the same voltage before use, AND we do not discharge the cells till dead to reduce the chance of damage to that one cell that may be weaker than the others. The cautious user will use for example three protected cells in series knowing that the protection circuit will kick in and prevent overdischarging of a single cell, but, the observant/ aware user will simply use three unprotected cells and monitor them carefully during use.

13:00 I often cheat on the figures to make it look bigger.

I nearly wrote a comment complaining about the way this pack is wired, then I suddenly remembered that about 95% of all of the sub-$60 Li-ion gadgets I've dissected to date have been set up exactly the same way -- cells in series, no balancing, and basically zero f*cks given by the manufacturer. Re-purposing 18650s, I've come across my fair share of dead or reversed-polarity cells.

due to differing internal resistances these cells will likely vary in voltage more and more after a few charge/discharge cycles.

Hi Clive, You should be able to create the imbalance fairly easily by discharging one of the cells partly, no? From then on the imbalance should persist for a fair number of charge cycles.

I made a similar thing with a slim aluminium extruded case and 3 18650s inside to allow me to use a little 12V power tool I have without having to use the mains adapter, but for the sake of an extra quid fifty I stuck a 3 cell BMS and balance board from ebay in there too. and re the voltages of the DW01, it depends which version. theres a DW01a, DW01b, c etc etc, all the way up to g I think, each with slightly different detection and release voltages for over and undercharge

I suspect that the 10S battery on my e-bike has a similar dodgy protection topology, but the battery case is so tightly packed that I can't safely remove the individual cells and restuff it. Any ideas on reconditioning the cells in situ?

in some mobilephones, the Li-Po battery is rated to be charged up to 4,35 or 4,4V and all apps mesure this voltages in the battery so, maybe some batteries can be charged with up to 4.4? instead of 4.2??

I tried to make a 12 volt battery for my hand held CB radio which came to me used with no battery pack. I soldered three of those same type batteries together and charged them up. Well somehow the CB was left on for a few weeks, and when I picked it up, the battery was dead. I opened the battery box and the center battery had swelled to the max, the other two batteries seemed OK. I tossed the swelled battery and still have the other 2 however I decided to use an external battery pack when needed for that old CB. (large GE hand held looks like a WWII Walki-Talki but in near new condition) 3 channel 3 watt radio with huge pull out antenna!)

Had a few of these i use for bike lights (security camera battery packs). I was pondering adding some leads for balanced charging using a lipo blance charger i have. Dont want to burn the house down though. Whats the explosion risk? 😞 disapointing to know i wont get full use of the capacity if one of the cells is dipped. Any workarounds for that? (Im awful with circuits but here to learn 😅)

what if a fairy high value resistor was used to shunt the cells to each other? would that balance them and allow it to work normally too?

What if you stick a beefy 4.7V Zener across each protected cell (on the protection PCB)? Wouldn't that correct any imbalance exceeding 0.5V total by bypassing the cut-off fully charged cell until the other two cells exceed 3.95V average? Extreme imbalance might charge two cells to 4.25V and the last to 3.2V. A lower Zener voltage could improve balance at the cost of higher leakage.

Over time, the balance will be lost, albeit probably very slowly, as one battery wears down faster, so it's capacitance also varies from others.

I once had an exact same looking 12 V power brick explode on me on first use . . Should have the pictures somewhere still.

Having worked in the hobby industry since lipo cells had no balancing input! I can concur what actually happens is you get 3x cells that should be 3.7v nominal so 11.1v 3x 4.2v no load per cell means 12.6v but as the cells drop off you still get 12.6v no load but spread between different cells.... I.e 12.6v fully charged but with silly cell killing variances like 4.2v cell one 4.0v cell 2 and 4.6v cell 3 this caused the rugby ball "puffing" of Lipo cells and even explosions and fire of generation 1 cells, gen 2+ saw protection circuits and balancing introduced as well as fibreglass tape to stop the over expansion of cells and inevitable fire etc afterwards.

WHO DID THIS?! It's a magical battery mystery!

The adding capacities reminds me of some 3S jump packs I got that a discharge-charge test seemed to suggest 1/3 of its claimed 8000mAh. As for no balancing - you should look at the the 2S lithium radio transceiver batteries - most seem to be 7.2V unbalanced with just a + and - connected in the charger. I would love to hear what you think of that. A Baofeng UV5R can be had for $15-$20 USD on ebay and about $25USD on Amazon...batteries separate probably cheaper.

The differences in self discharge alone will start to introduce an imbalance over time. Granted self discharge is also dependent on cell voltage, which will help a little bit, but yeah, this is not a good solution.

Hi Clive, probably not the best place to ask this but what would be your recommendations for powering a homemade bluetooth speaker. Input to the bluetooth amplifier card is between 7 and 20v and ideally want to charge it as I use it connected to a USB charger port. Any help gratefully received.

I can't believe I haven't subscribed before I feel like I failed at life

Balancing is often seen as a good thing but in fact that is a bit useless. If at manufacturing they are discharged and then charged until one is full then even if one is only 80% full then it's just that that one has 20% more capacity and all the cells actually hold the same absolute charge. When you discharge them again then they all go back flat at the same time. The balancing circuit is really helpful if you want the maximum possible energy out of the system because it makes sure that the charge is delivered back with the highest possible voltage but the Ah capacity remains the same, limited by the weakest cell. Another slight advantage of balancing is that aging is probably more even because it's charging to full capacity that wears the cell. But this can be seen as a drawback because it doesn't reduce the wear of the weakest cell, it just increases the wear of others...

Yup, using the battery safety circuits for cut offs are the new cheaper batteries. I had a Bluetooth speaker that did the same. It’s not good, the protection is also within %5 to 10% accuracy as well. Protection circuits were for preventing one cell running away into another cell and stopping thermal runaway. It was never intended for charging, one less thing to make it cheaper and charge you the same cost to buy. I don’t like this method at all.

Could you discharge one of the three cells and dis-balance and see how they charge

hi bigclive. i am wanting to build a battery bank. but im not 100% sure as to the charging of it. i intend to use a bms board to control the charging and discharging, but need to know if the charger for this system needs to be a dedicated lithium battery charger (due to the needs of the cc/cv stages). or can you simpmy use a generic battery charger and let the bms take control of the charging stages? can you shed any light on this for me? much appreciated. keep up the good work! love your videos

At least it has protection. Though, if one adds a diode and resistor over each protected battery, then when the protection kicks in, current can still flow through the diode and resistor. So that one at least could charge it more fully and even it out at the top at least. (The diode is so that we don't discharge the batteries when not charging, and the resist is there to make sure we aren't dissipating the full 4.2 volts in a diode. And yes, this "balancing circuit" doesn't really do anything during discharge at all.)

Multiple protection curcuits are really key these days but can be lacking

almost all power tools ice taken apart dont have balancing in their 18650 packs, even the namebrand ones, not even balancing cable for the charger. i heard that manganese cells dont require one, not sure about that

Yeah that's not ideal. Unlike NiMH, Li will not find an equilibrium between cells so they will "run away" from each other so the voltage differential will get larger and larger. You have protection so there is little danger but the effective capacity will plummet. Shove a 4V2 zener between cells, will be reet haha

Not only is the whole pack capacity limited to the lowest capacity cell, it is also limited by the difference in state of charge of the cells. In the worst case, if one cell is fully charged, and another cell is fully discharged, the total pack amp hour capacity will be zero. When you try to charge the pack, the fully charged cell voltage will rise above the cuttoff 4.2x voltage and break the circuit, and when you try to discharge the battery the fully discharged cell voltage will drop and break the circuit. You can "fix" this problem by manually charging each cell to full capacity with a bench power supply, and hope that the state of charge doesn't "drift" out of balance too quickly. Sometimes you will get a bad lithium cell which self discharges sitting on the shelf- something to do with spikey crystal structures that grow inside the cell, which will cause the pack to go out of balance more quickly. That sound right to you guys?

Clive is there a device (IC) that you can easly make a DIY cell balance controller with that you know of? I think that the cells over time will in the case of that power bank will drift.

The supply seems to have a generous primary/secondary separation on the pcb

Ok, here's the thing about balancing. People get a little too hung up on voltage. Not all cells have the same capacity, so on one cell, you may put 1900mAh into it before it hits 4.2, and on another, you may put 1980mAh. This discrepancy is normal, even perfectly matched cells will age differently over time. So you have to balance them to get the most capacity out of the pack. Now, you can top balance - that is, make sure they all hit 4.2V simultaneously. But, because the capacities differ, when you pull 1900mAh back out, you will deplete the "smaller" cells before the "larger" ones. This means the smaller cell will hit its 2.5V (or whatever threshold you set) while the others are still above that. So when do you cut off, exactly? When the cell hits 2.5V under load? Or when it hits 2.5V with no load? Batteries sag a little under load, so 2.5V while supplying 2A is not necessarily empty. But if you keep discharging, things start turning sour. The voltage curve at the end of charge is very steep, so it doesn't take much to drop the cell voltage down to 2V, or 1V, or 0V. When that happens, you set yourself up for reverse polarized cells, and then comes our good friend, fire. If you bottom balance, then all cells hit the steep part of the discharge curve at about the same time, so the ability for the battery to deliver current falls swiftly and it becomes quite clear that it is truly empty. Even still, draining to 0V when all cells are balanced is not necessarily terminal, since the possibility of reverse polarity is minimal. (There's no current left to reverse charge the first cell to hit 0.00V.) But.... you DO have to watch the top end - when charging. One cell will hit 4.2V first, and at that point, you need to stop. It doesn't matter if the other cells are only 3.7V - you've filled the capacity of the lowest cell, and that's all you're going to get. When you discharge, you'll take out what you put in, and all cells will again hit bottom at the same time. The top voltage is all but irrelevant. And since you typically charge at a constant current, it's a lot easier to control the HV threshold trip point than trying to guess whether you've really hit the LV trip point under load. Monitoring circuitry is still nice to have, but it's not really critical to see every cell's voltage. You're always charging from 0 to some capacity, and then taking that same capacity out. Since LiIon cells don't self-discharge unless they're damaged, they won't drift apart appreciably over time. A per-cell HV cutoff is really all you need. In fact, monitoring individual cells puts the tiniest load on them, and creates an opportunity for imbalance since the cell monitoring current (albeit small) won't ever be precisely the same. Then you DO need re-balancing circuitry, and you've just made things more complicated. So this simple design is not terribly safe in the event of corner cases -- such as internal shorts or some other abnormal imbalance - but, in the normal course of operation, it does exactly what it needs to do to keep the cells happy and no more. (Although 4.25V is a little too high for my taste.)

if not balanced and not precisely matched, I'd expect the difference in charge between the top charged and lowest charge ones to gradually increase over time until the pack stops being usable for no reason other than you can't charge the top cell or discharge the bottom cell anymore and you'd think it dead.

Hi Clive, I want to create a 12 to 18v battery pack using lithium cells, say 3x4.2v (12.6v Max). X4 packs in parallel (3000mah per pack) making approx. 12000mah pack. Can you tell me what the best way of charging this packwould be and best way of protecting it with say a bms board? Much appreciated. Look forward to your reply. Love your videos. Excellent work

Just a question about that LED technique, using the green on constantly and lighting the red to swamp it out, as a red/green color blind person would that likely explain why devices that have a green power LED that changes red when the power is low (like the old DSLite) are so difficult for me to distinguish the two states unless I actually observe it switching between the two?

I bought one a few years ago as i wanted a portable 12v supply. Biggest bag of shit ever, just didnt work, recently took the cells out though and they seem to be good individually.

hi i want to cut the power from hdd s with a switch 12 v , 5 v in one button can you help thx

Frankly, a pack with no balancing and with the battery manufacturer's protection boards is likely much safer than a pack with a chinese balancing circuit. With protection boards, balancing is just a matter of long-term performance, not safety.

this is interesting, I know its not normal for a balancer to fail in a way that it can inversely charged any cells promoting damage to the cells. but I wonder if the cell chemistry is getting to the point of the lower amperage cells are safe enough to do this? or will the difference in voltage force a current out put between the different charge batteries would be just as destructive as it as been supposable has been in the past. I would imagine that so long as the cells are as close as they are of don't stray from there safe charge/ or discharge levels, It wouldn't be to bad. I have been using 12 LGdbhg218650 and B18650ca wired up for 12.8vdc max charge using only inline single cell protection. but I also have not ran either cell type up to its max discharge rate. they have been discharged using a 5v 50w regulator running a Raspberry Pi 3 B, a 7 inch touch screen and a keyboard as well as a mouse, a few times with a usb to Sata connector for the Raspberry Pi. In this configuration, no cell dropped below 3.7 independently and only a 0.01v variance between cells.

you should show your batter capacity and discharge method

I think that approach is OK Clive, though over time it may well prove to lack a degree of robustness or efficacy.

Doing the volts comparison at 5:00. Isn't it ironic that the smallest looking cell (top one) has the lowest voltage, highest voltage is the middle cell which looks to be the largest looking cell & the midway voltage is the bottom cell which looks to be in-between in size comparison?

Ever thought of opening up old video game consoles, hey I know you do pinball games, I guess this is just a few stages up

Can I please make a teardown request Clive? There are replacement rechargeable 9v batteries available that use 2 x LiPo cells and are USB chargeable. They sound promising but only if the cells are balanced and the output is modified to give near 9v over most of the discharge range... Thanks for the videos.

Question: what does a whiffy electronic smell be a sign of? Is it an indicator of something a miss?

NO balancing circuit, one disapproves especially for lithium cells, I've even considered adding a connector to my drill batteries so I can balance them from time to time.

hi clive. love your videos. what are your thoughts on lithium battery packs, specifically the 18650 packs either 3s4p 3s2p etc etc. do you have any input on their safe charging and discharging? what bms modules would you suggest to use for a quality 4s2p or a 4s4p pack? would love your input. many thanks

I was about to buy one from amazon

Will the cells charge each other to level out?

They were like, "Let's not completely lie (6600mAh) but let's not tell the truth either (2200mAh). Just slap on '4800', that sounds believable."

I want flames from a lithium cell, so far the only way I have managed that is with a gas torch. I have tried over charging ( 12 volt car battery straight across) nail right through, cutting with tin snips and even shooting one but so far the most is just slightly warm. It seems to me that they are not as dangerous as some make out.

Well, in the bad old days of NiCd and NiMH battery packs for cordless drills, they didn't use balancing either. The weakest cell would dictate the lifespan of the pack. It would ruin it once it had degraded far enough to allow reverse polarizing, and I believe that especially NiCd wouldn't recover from that (not sure about NiMH). IMHO the most important reason to use balance charching on (plain) Li Ion cells is the safety. Mild overcharging NiCd or NiMH wasn't particularly dangerous, but something Li Ion can have a much more severe reaction to, as we know. I guess this particular power bank was slapped together using protected cells and a "meh, that'll do" attitude. A self respecting manufacturer would have used balance charging to also optimize the overall lifespan of the pack.

Oi Clive I want my screw drivers back 🤣🤣🤣🤣🤣🤣🤣🤣 hope you are OK and safe

Ive seen them use the High Drain feature to get to their rated output, Just like those jump starters do, listing a 800 Amp output but 3 cells each about 4000mAh at 3.7V, searching specs will show a high drain feature of 25A and Im guessing they twist the numbers around and use the High drain and the peak surge to come up with a WHOPPING 800 Amp when actual is at the 4A at 11.0-12.6 V . I have SO MANY modules and batteries here Id be more than happy to share with you some like my huge flat Li-Ion cells that have real specs of 3.7VDC@ 8Ah and a high drain of 200 Amps (Get this and its true, I did a high drain of 100 A and stopped there LOL)

At 8:22 a little crater you say, so that is where the magic smoke did a great escape then? 9:42 is that the good smell or the bad smell? 10:50 J3 Smudge - get the flux out of there

Hay clive i have a phone charger from ebay that has not working any more can i send it to you to open it up ???