Inside the new Poundland Power-geek 2200mAh power bank.
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- Опубліковано 10 вер 2024
- A comparison between the new £2 Power Geek 2200mAh power bank and the standard £1 1200mAh unit.
These units both put out 5V continuously with no glitches or low load shutdown. This makes them suitable for running low current loads for long periods of time.
The slight roaring noise in the background is another typical stormy night on an island in the middle of the Irish Sea.
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Thanks for the big photographs of the circuit boardsm Clive. They are really sharp and clear. It makes your explanations very easy to understand.
Nuts n Proud aa
I think they get away with calling it "2200 mAh" because the cell's capacity is 2200 mAh at 3.7 V. The amount of energy in the full cell is fixed, so when you boost the voltage up to 5 V, it can only supply around 1700 mAh.
Yep, exactly this :) It's not "getting away with it", either - it's how all power banks (and other lithium cells) are rated. And that's generally the value you're interested in anyway, because your phone's battery will be maybe 2000 mAh *at 3.7V nominal*, so the mAh at 5V is fairly irrelevant.
In this case, 1708 mAh at 5V = 2308 mAh at 3.7V assuming 100% efficiency (which it won't be).
You can work that out by taking the 5V capacity (1708), dividing it by the lithium cell nominal voltage (3.7), then multiplying it by the USB output voltage (5): 1708 / 3.7 * 5 = 2308.11 mAh. :)
That might be true, but as a consumer I have no idea how many cells they put in series in their power banks, making this number completely worthless as an indicator of stored energy.
@@anlumo1 I've never seen a power bank with more than 1 cell in series (besides the jump starter packs). They've all been lots of cells in parallel. So generally that mAh rating is good for comparing products at least. Ideally you'd want to compare Wh, but that's rarely given...
Ok, good to know. It also makes sense, that way they don't need a balancer.
Listen - Big Clive, would not have got where he is today, by not knowing how to calculate power bank capacity (╯°□°）╯︵ ┻━┻
As I work in quality check for multi layer ceramic caps I can tell you some details, which are of course also available through intense searching on the Web.
Depending on the voltage rating, the thickness of dielectric ceramic between the nickel electrodes can be as low as 1 or 0.5 microns, resulting in many hundrets of layers and thus high capacity such as 10 microfarads rated for 6.3V in a 0603 package (1.6 × 0.8 x 0.8mm). To achieve a rating of 100V the ceramic layer has to be around 9 microns.
Also, the mentioned sensitivity to cracks is mostly absent from the smaller packages and becomes more noticeable with big ones. This can be somewhat prevented by a soft layer in the outer terminals consisting of silver and a polymer which gives some flexibility, also called soft electrode.
Keep up the nice work, I really enjoy your videos.
That is really neat,thanks for sharing friend!
Alex.
amazing...!!
This man is a beast, nothing survives or retains it dignity
Here in Romania the same power bank ( at least the same shape, construction) is called Promate end sometimes eBoda. Bought one. The first time i plug it to charge, i got lot of smoke end some flames to. Wery exiting to watch.
You obviously got the Ashens version. The bigclive version only does that if you put it in a pie dish.
Why do people thumbs down BigClive?
He is ALWAYS awesome!
I often wonder who they are..there was one geez who actually left a comment questioning BCs technical know-how...LOL
Whaaat !!
@@keithsaladine6051 YEAH GEEZ...!
1.6K 👍 15👎
Not too bad. I suspect some of those 15 are from people who just missed in their aim and didn't notice, and the remainder includes entitled people not worth thinking of who may have come here from a UA-cam recommendation and various troglodytes.
@@Peter_S_ ...troglodyte...hahaha...troglodyte !! ...great word 👍
I bought a USB load testing setup after seeing you use them, turns out it's good for load testing the 5v circuit on rc airplanes because the receiver can brown out if the voltage drops too much.
If I've learned anything from Ashens,
Don't trust anything made by Signalex.
some of their stuff is ok,,
The photo print out presentation was Perfectly done. 10/10. This is a win for paper.
Poundland trades in Ireland under the 'Dealz' name. They sell the cheaper power banks for €1.50 which is a substantial markup on the UK price.
I've found that they suffer badly form self discharge, going from 100% charged to almost completely discharged in less than 24 hours.
I believe Clive's is also a Dealz
Couple of points. If manufacturers switched to Wh instead of mAh - we could easily compare the capacity of cells, even those with different technologies/voltages. Secondly, I would be surprised if the boost converter in the power bank was more than 90% efficient. The efficiency is not fixed either, it varies according to the load...
Why watt-hours though, why not just joules? Joule-hours-per-second is just such a strange unit.
Actually, sod it let's go full base unit - kg m² s-².
Haha yes. Electrical devices usually/often have their power stated in Watts. If the batteries used related units, it makes it much easier to work out how long something can be powered. If I said I need to power my LED floodlight that uses 20 joules per second of power, which battery bank should I buy? Well...
And I think Wh would be joule-seconds-per-hour lol
A watt is a joule per second, so logically a watt-hour is a joule-hour per second. You're just multiplying both sides by time, in hours.
I agree about mAh anyway. Again, we already have a unit of charge - coulombs, and it only makes sense in terms of capacity if you multiply by discharge voltage, giving mVAh, or mWh, or Wh, or just back to bloody joules again! (Or kilograms metre squared per second squared, although admittedly that's a bit inconvenient).
I just like joules because it'd tell me roughly how many seconds something would run for, providing I know the average power output.
Well I think we can probably agree that mAh is only convenient for comparing batteries that have an identical chemistry?
Well, 5 Volts is 1.35 times 3.7V, so if you calculate 1700mAh times 1.35, you get about 2300mAh, so the cell may actually be a 2200mAh cell, just not at 5V - that's the problem with powerbanks and all these things: They never give you an actual value for their capacity, which would be in Wh, not Ah!
Ah! I have the "big brother" of that USB load - mine has the built-in USB volt/amp/watt meter as well as all the cable connections; that's turned out to be extremely useful for finding crappy USB cables with the help of a previously tested USB power supply. (That is, if I know the power supply dips to 4.95v at 1A, but with the cable in between it goes down significantly - then I know how much cable loss there is.) There's a ton of garbage USB cables out there and it's amazing how satisfying it is to throw them away and replace them with one that WORKS.
Best to compare watt hours. 1700mAh*5v is 8.5Wh. 2200mAh*3.7v is 8.14Wh. Energy going in is only slightly above claimed capacity, which can be easily explained by losses.
This only applies with switching charge circuitry.
EDIT: 13:05 Its a linear charger so it is indeed somewhere in the region of 1700mAh.
@Weedus Those labels are showing how much current each port is _capable_ of delivering. A standard old USB 2.0 port on a computer only outputs 500mA (or 0.5A) max. I think the newer USB 3.0 ports go higher to 900mA. So older devices and low powered devices with small batteries e.g. like my Garmin running watch, will only need to draw small amounts of current and you could use a computer port or either port on your power bank. Newer devices such as phones and tablets _can_ charge at 500mA but their batteries are much larger capacities these days and they'll take a long time to fully charge at those low currents. So your Samsung or iPhone etc come with dedicated chargers that can output much higher current than the original USB spec. Now my older Galaxy S3 could charge at a maximum rate of 1.0A so here you could use either port in your power bank and it would only draw 1.0A as that's all the S3 handles as an input charge current. However my newer Galaxy S4 can take a higher current, up to about 1,9A I think. This is where your ports will be different. The one labelled 1.0A will (or should?) only supply up to 1A so the S4 will still only be able to charge at that rate. But plugging it into the 2.4A port instead will allow it to charge at the full maximum 1.9A that it's capable of - because the port is capable of putting out that amount of current. This is all at standard USB voltage which is 5v and is also highly dependent on using a quality USB cable. Next came QC or Quick Charge which I don't know much about but changes from standard USB 5v to 9v or even higher, so if you see those sorts of labels on your powerbank they're doing something slightly different again.
@Weedus So yes. The 2.4A port will charge your devices faster so long as those devices are _capable_ of charging at higher currents, AND you are using a good quality USB cable.
Adam, yes watt hours are better, but you can't just multiply by 3.7V because 3.7V is open cell voltage, and as cell is drained the voltage drops. It would be reasonable to take a mid value between open cell voltage and cut off voltage, so maybe 3.6V? 3.5V? Definitively less than 8Wh in energy amount. Plus the fact that efficiency of the conversion varies with load and input voltage. You would need to have an access to a lot of data to calculate everything precisely.
movax20h 3.7v is nominal for a lithium ion cell. It’s also the point in the discharge graph which holds for the longest time, and practically in the middle of max and min. I think it’s a fair point to calculate from for us mere bench top hobbyists making a quick judgement.
The rating is the battery at it's typical voltage, meaning it's likely a legit 2200mAh battery in there, however you will never get 2200mAh of current after it's converted up in voltage. For example 3.7v at 2.2Ah = 8.14Wh, this is the true power of the battery. When boosted up to 5v, naturally the current will now be 1.62Ah. So the fact that you got 1.7Ah is pretty good.
Of course labelling it like that is dishonest, because the average consumer doesn't assume that the mAh rating is what the internal batteries are at if drawn upon directly, they assume the mAh rating will be for the output socket of the power bank itself, the USB output.
The printed out photos and schematics were excellent, thanks Clive!
A local charity shop here sells powerbanks for 5$ a kilo. They even have Ankers and some huge 16,000mah ones too. And yes i have WAY too many now...
I'm glad they don't do that here. I'd have several kilograms of power banks for no good reason at all.
Gotta burn down your house somehow right? (:
Alex.
I wish I had that charity shop near me. I could use a few pounds of power banks.
@@inductorbackemf7204 I know :D I have too many cells i don't need but i wanted to use the other parts (COB leds and solarpanels)
@@BigClive And the worst thing is they keep re-filling the boxes with them everyday. They come from the airport. They seize them from people who bring too many.
The inductor and capacitor between the inductor and ground is a snubber network. As the chip is a CMOS part its maximum voltage is 7V. Spikes at the switching load can go above this and kill the chip. These shunt HF spikes to ground. The spikes can get worse at low tempetature!
Great review. Thanks.
Was waiting for this video. Will pick one up next time I'm in Poundland now that you gave them the OK.
I modded a portable radio that used 4 D-cells to use one of the 2200mAh banks. Works a charm although does create some interference on MW.
What's the battery life like as compared to the old 'D' cells.
Thanks to your earlier vids I've got two of the cheaper Poundland circuits driving my Atari Lynx. I replaced the cells with Samsung Galaxy Note III batteries which give 3200 mAh each.
Bought one of these recently. It had a different part number than the old one and tested better.
I bought three of the £1 powerbanks from the leamington spa poundland, (my phone was totally flat and I needed to make a call.. couldn't get a car charger for love nor money) luckily there was charge in them straight from the shelf, but when I got home and tested, the best of the bunch was only 650mah, the others under 600.. I was a bit dischuffed.. but at least I got to make my call.
I think the marketing-speak (or 'wank', as AVE would call it) would rate that 2200mAh power bank as 2200mAh "notional" (i.e. around 1700mAh). A similar trick is being performed on all those windmills being installed in Scotland, the main difference being that the people buying them and well as the people selling them are in on the same con :-)
Man I can't get enough of this channel.
I'm not sure if I'm the only one who'd feel this way, but I'd love to see videos of the bad weather you experience :)
before you can rebuild you must destroy...anarchy in the Irish Sea !!
I second this!
I’ve loved big Clive for many years (2013ish) because of my dad, never understood what’s going on in these videos but I still find them interesting. Recently been watching the ones I completely do not understand at all to go to sleep because Clive’s voice is calming.
A lot of people use my videos to help them sleep.
CLASSIC...CLASSIC...CLASSIC..you know what Clive...the amount of expression..nuance your hands radiate is poetry in motion...the whole shebang..dialogue..voice..AV
aids..delivery..a classic big Clive..!! thanks!!! ..edit....[do you have any Greek genealogy]
Not aware of any Greek family connection.
Big Clive has the knowledge. Very intriguing video.
Love the fan tester
Bought several of these following this vid. The 2200 had gone up to £5 but the 1200 was still £1 and that is what I bought. Plan to swap out cell anyway - really wanted a mp3401-based unit to avoid pass through cell voltage at low charge level. Thanks Clive !
Lol today 26 December 2018 I brought poundland emoji power bank 4000 mah one for five pound so you are wrong about the 2200mah one
Soooo many new videos recently. Thanks Clive
Nice. Clive and a beer!! I was in there today to get some bits, and spotted a partially open (brown shipping box on the racking above the display) box above the power bricks and headphones. 4000mah power bank. Different form factor, flat and wide - with a torch. £5 so I didn’t get it lol. But curiously it wasn’t on the shelf anywhere perhaps next week they’ll display it..??
I've got one on test at the moment....
Most likely 2200 mAh is the cell capacity at 3.7V. Boosting that to 5V gives a lower capacity measured in Ah. Kinda a slimy way of rating things.
correct. conversion losses not taken into account. problem is every one rates it this way.
I really liked going to the Nicolson Street Poundland too, they had so much stuff, cheap items and great DIY and electronics stuff, it was perfect for students. When it closed the next closest was Meadowbank Poundland, an hour walk (one way) from my flat... Thought they already had enough Sainsburies... There’s one couple hundred meters north and one few hundred meters to south on the same street, plus all the tens of others closeby.
those power geek ones are exactly the same as some called Trust/Urban Revolt here in sweden.I also had the problem that the capacity wasnt enough to fully charge my phone.
Yep, I have two of the double cell variants from Trust, one indeed with the Urban Revolt sub-branding. They're 4400mAh and my phone is 3400mAh, and they aren't depleted after charging my phone fully once, so I can't imagine it's too far off. I'm about to run a proper discharge test, will report back!
I have the double cell one also that one does charge both my phone and my tablet fully, not on one charge though.
Some of the xiaomi powerbanks got "low power" mode so you can power your lights or other wireless headset
Thank you for all your video's. i love them.
Ive had one of thouse for over a year, i live in portugal, and i bought it for around 10€ (kinda scammy) in a retail store. the circuit its the same, so its just a rebrand. it ran hot to the touch, and after 8-12 months of use the the usb type b thats for recharging just popped off on my backpack.
I've seen them £2 power banks in my Poundland and gonna get some they look very handy great video as usual
Would be interesting to connect 2 of the 1 pound cells to one connector (keeping both boxes, maybe hot glue together) and see if that's not better value for 2 pounds. Gives you a spare connector for another project too.
There are advantages to using these simple modules with larger parallel cell arrays. These modules stay awake and supply 5V all the time even with low loads.
The quoted capacity is usually the capacity of the lithium cell. So 2200mah at roughly 4v of a lithium cell works out to about 1800mah at the 5v of USB.
ill grab a few of those at the weekend should be enough for a 50% boost for my phone, they look much nicer than the
£1 ones.
what happens if you connect its output to its own input does it charge itself or can it detect something is weird?
I'm curious: How much of the difference in capacity between the bare cell (and/or the rating on the package) and your measured value is caused by losses through the inverter rather than any deficiency in the cell itself? In other words, how efficient is the inverter and/or how accurate is the capacity marking on the bare cell?
mharris1270
Thanks for the response. I appreciate the effort you put into it. However, I wasn't asking what manufacturers claim or how other similar devices may perform. I'm also aware of the various factors involved which can cause (as you say) a fairly wide variance in performance (but I have no doubt there are others who will find that information useful).
I asked specifically for the figures from the device shown in this video. Therefore, despite how generally-informative, skillfully-presented, and potentially-useful-to-others your answer is, I'm saddened to have to inform you that I must chuck it directly into the "irrelevant to the question at hand" bin. Sorry, but I'm sort of a dick that way. ;)
(No, I do not expect Clive to go that level of effort for such trivial information. For that matter, I don't even expect him to bother responding to this petty request!)
a lot of the 18650 batteries r actualy fake. Amazon r very fond of taking real batteries and taking the covering off and putting their own on with a higher mAh.
Only way to get the real batteries with the right mAh is buy direct from the makers rather than through 3rd party sellers.
When i was looking for some 18650 batteries a few years ago to power a model i made of RD2 D2 i was after some 3200mAh. on the samsung website they said there ones only go upto a max of 3200 but amazon were selling samsung 18650 4600mAh So they were definitly fake ones relabled by amazon to scam buyers.
Might be what happened with the batteries in this powerbank. the bateries they bought were probably lower mAh than printed on the label cause the supplier removed the correct label and replaced it with a higher mAh so they could charge a bit more.
Poundland probaly didnt even bother to check to see if the batteries were the correct mAh as they got them cheap. But all retailors r the same buy as cheap as possible and sell for as much as possible. without checking to see if they r the real deal of fake as long as they can make as much profit as possible. But buying cheap stuff doesnt always mean ur buying crap. Some expensive stuff is even worse crap than the cheap stuff.
I remember years ago Harrods were selling tins of heinz baked beans for £5 per tin everywhere else they were 40p a tin lol same stuff but diff price. Most cases ur paying for the label or brand rather than what ur actualy getting.
i was also sad to see Nicolson Street poundland go. One on Princes Street is good, as is one on lothian road. Both handy for edinburgh castle
Clive, you make technology accessible to mere Humans. Admirable. Oh I suppose I could spew on, doesn’t matter ...
I have 3 with the name 3SIXT all battleship grey. They have the same shape exactly as the Geek ones and mine came from Dick Smith Electronics about 4 years ago, not long before they closed down. Two are now dead, don't charge despite the red light, the last is still going but has low capacity and a bad connection on the micro USB
mahn i appreciate the effort you put into these videos
Nice one! I have been playing with the £1 model to power a microcontroller and 50 ws2811 fairy lights, works a treat. I had a few of the Poundland Powerbanks and opened one up today to see what was inside, the chip code was scratched off on my one so this video cleared it up :)
Love your vids you clearly have a big brain.
Poundland opened a store on Lothain Road so can get your fix there next year..
Ah yes, I did find that one near the end of the job.
There is a branch at the Meadowbank retail park too.
I had a couple of old style 1200mah poundland units and I swapped out the cells for some nice high capacity Samsung ones.
FrontSideBus Where does one buy quality 18650 cells?
I have one of each with estimated capacity of 570 and 1130mAh respectively, so mileage varies. For the money though, they are useful and you could always swap in a decent quality battery for a few quid.
Even the £1 one runs a a 5 led flexible arm light (also £land) for many hours.
They are useful as project bases for not much money.
Great video as always Clive.
I am always impressed by the photos that you enlarge and print out. Can you tell me what printing set up you use?
Thanks
Pictures taken with my phone in good light and then printed on cheap glossy photo paper with an Epson ecotank printer.
ok thanks Clive. I have an older Epson and was looking to replace it.
Go down to Homebase and grab a £1 solar fence light. Just got 2 and i'm surprised how well they perform for a quid a piece. Be interesting to see how waterproof they actually are.
I wonder about something, because in the past, when Lithion Ion batteries start to get a little bad on me, I'd put them in a freezer in a sealed bag for a night, let them thaw out in the morning and they generally tend to work better. But I've never done any measurements, because I don't have the gear for it.
But it makes me curious if it actually makes a difference for such power banks!
make I
suggestion have you ever tested the juicy range of power banks they sell in Argos etc and boots etc thank you
Nice, thanks for sharing😀👍
You're finally back from Embruh!
I bought that Uni-t meter cause I saw it on your channel and man that thing is so slow to update I don't really think I would suggest buying it.
Should get yourself one of those UM24 USB testers.
Straight to the point. love it👍
I think the difference between rated and measured capacity is due to different voltage (5V vs. 3,7V) and the efficiency of the conversion. Manufacturers of powerbanks usually print the battery capacity on the case.
The one of these I have is also pink, is branded Travelocity, claims 1800mAh on the outside and cell, uses a Tpower TP4303F chip and a 2.2uH inductor instead, actually has the DW01B chip, and there are no wires, the nickel strips from the cell are soldered directly to the board. Oh and it cuts out at low load so I can't use it for my Ikea gooseneck USB light.
Another thing about the ceramic capacitors are that they use XR7 dielectric. The capacitance varies with voltage. That means they're okay for bypass and suck for anything else.
Presumably the capacity listed is that of the lithium cell. That's going to be at least 30% higher than the power bank output because of the boost SMPS in the power bank that takes you from the 3.8v of the cell to the 5v output.
Those cells look like they have the protection circuit integrated onto the end. If so, there's no need to duplicate the protection circuit again on the board.
I found an Acme PB02 2200mAh power bank from e-waste bin that also works well with low loads. This one has three 6-pin chips - 6291, DW01 and 67D5._
The design of these genuinely made me think poundland was selling vape pens lmao
I would say that battery capacity for the 1A Power bank with it saying 2200mah 🔋 is decieving for sure as most manufacturer put the voltage of the battery (3.7 nominal) and not the boosted converted 5 volt voltage of the USB ,also as with everything there are power losses.For your Math=
So let's see, 3.7vx2200mah=8.14Wh
Now assuming there is no loss then 🔋 capacity it will be 8.14wh 5v=1628mah.
12:30 The cells actually do have the capacity as labeled. The capacity is based on the total capacity of the cells while the power banks will probably limit the charge over 95% and under 15% meaning your useful capacity is 80%. So 2200mAh * 0.8 = 1760 mAh.
Thx for this video
looking forward to the valve item.
6:54 if voltage goes to low, you should not use it anymore. Can be dangerous.
This may be useful for strapping to my Zoom H1 as my existing power bank shuts off because the load is so low.
My local Poundland also sell a thin power bank made by " Intempo " Its claimed to be 2600mAh. label on the battery says Output 5v 1A. input 5v 1A. LiPo battery 2600mAh 3.7v 9.62Wh Come in various colours. With 2 led lamps plugged in its drawing 0.27 A but the voltage is just 4.87v with no load is 5.28v
very nice video, do you have a link to the battery monitor and the load?
how do you measure capacity? Do you take the 5V/3.7V discrepancy into account? Power banks are usually rated by the capacity of their battery I believe?
I run the pack flat and then recharge it fully monitoring current over time. So I'm measuring the cell capacity.
Hi Clive, I think this has been covered quite comprehensively in other comments today, but while you're here, the thinking seems to be that when you draw 1A from the 5V output, the cell itself is delivering say 1.4A because the boost circuit is acting like a transformer. The cell's capacity might actually turn out to be correct.
Is it worth carrying 3 of these £1 jobbies instead of my dearer 3 cell Xiaomi power-bank?
My Xiaomi is rated at 10,000mAh, pinch of salt needed to live with that figure, but it will do 1 full iPad charge from flat.
10k mah rated Xiaomi is actually only 6300 mah
Just stick a 3800mah cell in and its a great stick style powerbank right?
Yeah I plan to do exactly this
There exist actual cells higher than 3600? I doubt.
@@SianaGearz sure 20700cells go up to over 4000 and they will fit ^^
There are even 70a continous discharge 18650s and the specs are real , its all about the price you pqy
Oh, 20700 is a good point.
I know you can get to high current, but at expense of capacity. Not everything is possible, you can't just throw more money at it and buy a cell that is better than the industry state of the art, but you can save some money by going for last-generation products and third/second tier product lines and manufacturers.
@@SianaGearz i mean i have 20700s ijoy branded here that are 3000mah 40amp and some Sony vtc5a with 2600mah 35a
Both are good but i prefer the vtcs since they cost half and can handle 4-5a charge current of course the 70a 18650s are onmly 1800mah inner resistance is the Problem with lion against lipos
So I think I'm a Big Clive junkie - will be going to the UK (Cambridge) in a while, and I'm already excited about visiting Poundland. Think I'll probably get a "souvenir-edition" power bank in Big Clive fetching pink. :D
Love the tester Clive
nice review and teardown, wish you'd review some big boy power banks like the Xiaomi 2C, would love to see your thoughts on them
i dont think you mentioned this but those MP3401A chips get really hot in operation. im seeing 80c+ on both the 2200mah and 4000mah power banks. is this ok though? im not sure..
They do run hot. When charging the lithium cell they effectively act as resistors to limit the current.
@@BigClive ahh so insted of using a tablet 3amp charger using a iphone 1amp one is better?
I bought an identical powerbank to the 2200 mAh, but branded differently. Thanks for taking it apart, I was curious how they work, and what capacity they actually have.
It's interesting that the circuit has a minimum output current, under which it goes into standby. I guess that is built into the IC chip. I wanted to use it with a motion sensor powered led light for a closet.
I found that around 0.2 ma is the minimum which can keep the power bank from going into standby. I'm using an led with a 10k resistor to keep a load on it so it doesn't standby.
Also interesting that every few seconds it drops to 0.06 ma, and then back to 0.2 ma, like it's probing for something.. not sure why..
Im looking to buy a half decent USB power bank. I have seen 2 on amazon, one comes recommended at £19.95 and another one around the £30 mark. What do you recommend around that price mark?
You sometimes take stuff from other people to take apart, do you have some way for people to send you items for consideration?
I have a small, usb rechargeable fan that is starting to have problems that I'd love to see your analysis of.
The cheapo power bank I have has the same power bank logo on it, but is branded for Kmart Australia. My one also has an MP3045A as opposed to the MP3041. I wonder what the differences are?
I use the 1200mah 18650's as a power source for a torch (because I'm a cheapskate) and used the circuitry to make a charger. Could I use the "2200mah" cells in my dodgy homemade charger or would they not be fully charged or burn down my house etc?
Should be fine
It's all good. The one thing you have to be careful about is a charger trimmed for high-ish current (i.e. taken off a power bank) that it shouldn't be used on a drastically smaller cell unmodified (i.e. from an MP3 player) because generally the maximum permitted charging current is proportional to capacity. Correspondingly, if you take a charger circuit from a power bank and use a higher-capacity cell, you shall likely find that the new cell will take correspondingly longer to charge, but it'll be happy enough.
IF the cell is 1.2 amp hours but you have to boost the voltage, the effective amp hour rating will drop(to keep the watt-hour rating basically constant). Measure the current/voltage from the cell itself while doing the load test and see if it meets it's label then.
Clive, how are you measuring capacity? It's accepted practice for the manufacturers to quote the capacity of the cell itself, and that's clearly what they're doing here based on the writing on the cells. If you measure on the USB output and compensate for voltage then you're including efficiency of the output circuitry in the measurement, so it's not surprising that you're getting lower values. 1708mAh for a 2200mAh cell suggests around 77% output conversion efficiency, which matches other results I've seen for that controller chip at 1Amp USB.
Got a Signalex/Poundland 1200mAhr one here, marked model 170327, with the same PCB, same component values but it's got an SY3501C chip on it. Datecode appears to be 1813A6 which I read as week 13 2018. Can't find any data about it online.
Awesome, been looking at these in poundland for a few weeks now. Would you say they were safe to use regularly?
They seem fairly typical of cheap power banks, so will be OK for low loads.
I use one of these battery banks too power my Zoom H1n. Lasts for ages. Cheaper than buying rechargeable batteries and the charger. Also rechargeable batteries are only 1.2 volts.
Could you use one of the boards to charge/discharge two LIR2032 cells? If not, is there a resistor that could be replaced to tune it to the right current?
Yup, the Chinese will cut corners when they can. It's just embedded into their culture. This even goes for well-known brands like DJI and Xiaomi, but only for units sold domestically. Export units are alright. And yet again, the chip on these units show that the Chinese will not hesitate to turn to a cheaper chip manufacturer if their stock runs out or if they can save a penny or two at the risk of a handful of failures. And Chinese people just don't care. They buy something and use it until it breaks, and then they just buy a new one. Manufacturers, builders, and shops know that, and therefor produce crap quality.
curious what happens if you try run and charge the signalex at the same time ? box says don't try it.
I got the same Powerbank from KIK in Germany 1 Year ago for 4€. It has the Same Design and is made from PolyFlame but my has 2600 mAH.
I bought a power bank from an airport not too long Ago. Different brand. Exact same case (minus color)