Cheapest Power Bank Review (with Schematic) 

😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂😂it’s really tight inside Jesus fucking Christ😂😂😂😂😂😂😂😂😂😂😂😂

LOL STOPKJBSV DAHKJVAH SVKJG SFDVHJK

So its a girl the man is boy not she

Mine survived lol even though it emitted a lot of smoke

Mine put put a lot of smoke but... Didn't survive.

If u want it can still charge just remove the indicator of the circuit but u can't use the output usb port now. You can use the burnt up circuit by removing the indicator to charge lipo batteries

Inductor not indicator.

Emrldy same

It's like a portable 5v power supply

ಕನ್ನಡದಲ್ಲಿ ಕಳುಹಿಸಿಕೊಡಿ ಪ್ಲೀಸ್

@@user-sq9pk5xl7f fuikro

I have the pink one in PA and they work excellent.

@@kalebb9983 lol mine broke and I paid 10 € ...... lol

I got 2 of them with the cell inside, but I didn't know that there was a cellless model One is a green one and one is a blue one, I had won the blue one from some english contest thing in elementary school (the poster had a picture of a macbook and I would have been very happy if I had gotten that)

I also have one 4000mAh one with the low battery warning, and just recently I got a big one with 2 outputs, 2 inputs and the ability to charge my device while I'm actively using it

add a fuse

if you put to them some thermal disipation system it will work perfectly

5/3.7*1 is ?

Yes, it is really not so bad for the price :) except you have to have your own cell and there's no fuse in it. You are right, the inductor is 1.5uH. In the end of the video I've corrected the schematic :).

Sneaky, 9 seconds from the end :D I took off at 12:15 Yeah, the absence of a fuse is nasty. I use a very fine (0.08mm in diameter) magnet wire for that purpose, it pops above 3A. Not ideal, but works to protect from shorts.

Where abouts did you put the piece of 0.08 wire?

I'm not really concerned for the absence of the fuse. You get a decent enough cell, something brand name rather than a China made one, and i mean if you harvest something out of an old laptop and i've seen fresh Sanyo cells for 2€ on nkon, it will have a pressure activated disconnect - if you ever get it hot enough to boil the electrolyte, it should detach before the electrolyte can catch on fire :D And it does have a built in short circuit protection in the controller IC at least for external shorts, though obviously not for internal ones.

I just gived advice to someone else on this thread to try with 0.07mm wire :D

Gavin Davies True, but even these non-protected cells do have an interesting feature... it's called a CID (Current Interrupt Device). A little reading: batterybro.com/blogs/18650-wholesale-battery-reviews/18306003-battery-safety-101-anatomy-ptc-vs-pcb-vs-cid 😉😆

Gavin Davies do you get the battery along in poundworld?

I have the same board, but with two 18650 2500mAh batteries, and when charging the board goes extremely hot

www.amazon.com/USB-Charger-Doctor-line-Voltage/dp/B00S80CMBO/ref=sr_1_1?ie=UTF8&qid=1525600225&sr=8-1&keywords=charge+doctor You can get it there.

The battery was a good quality one, but it was quite old. The internal resistance may have been a bit higher due to a long storage. But anyway, I think that this powerbank is really good up to 1A, but sucks at anything higher.

I should say the cell is likely in very good condition, very low ESR! Otherwise, the power bank IC tends to run hot and explode in normal operation, like when charging or drawing half an amp, which is curious, because they claim that it has over temperature protection. It's recommended to install a ceramic capacitor parallel to the cell in case this occurs. In case someone fancies wading through Chinese language, i might have the datasheet somewhere on my harddisk, but i'm fairly confident that it has no mention of potential failure modes.

Mmmmm, thanks very much for the tip! I didn't know, of course; i will apply your advice (i bought one of these)

FREE FROM COPYRIGHT I think it should work,but dont know the pcb specifiction So dont try it,if you out of luck the pcb will burn out

Look into powerbank and change circuit

Buy new one. Costs less then one spare led

Simply replace it with a different circuit...

Jay Tee simply buy a better power bank

Not possible..simply buy another PB

@Nikunj bittu PowerBank

Wait who doesn't hold the voltage? The power bank turns off or the boosters misbehave in some manner? I suggest that it might be curious to tear down your router and see whether you might be successful powering it in another way - say if the input is a regulator to a lower voltage and 9V input goes nowhere else, you just dance around that and you're done. Depending on how the regulator is implemented, it might be fine with 5V input, but strain on components and thermal output will be higher, as they will need to pass more current - but it appears you have tried that and weren't successful. Another possibility is that the ICs and capacitors might take quite a bit more voltage if needed, and you'll probably find CCTV emergency batteries with pass-through that run on 12V. But we really need to see and probe around your DSL modem circuity first, don't just try - take it off the power and run continuity meter to see where everywhere the pin of the power supply goes inside the router, as it might be impossible to reliably determine visually, as it's likely built on a 4-layer PCB. Another thing to keep in mind is that you can use a step-down after the 12V battery if not certain. I don't anticipate that you shall be successful with two of these in series - i mean, they don't take kindly to being supplied more than 5.5 or 6V at the input, usually resulting in instant death, and there will be all kinds of border conditions. The MP3401A (and i got some power bank boards where the IC surface is unmarked that are the same) actually supports charge-through, but as you see, it doesn't take too kindly to being drawn a lot of current from, it's best under 0.9A at 5V, and your original power supply delivers slightly more power in total, considering conversion losses. What kind of duty cycle do you need to support? Is this for emergency use only, does the power come off only once in a while, or is it something that needs to hold you over multiple hours a day? I have a few more ideas on what to do, but need to determine the design parameters. As to something to replace the Xiaomi when you have to or get another equivalent device, well the problem is, Li-Ion batteries can no longer be easily shipped by air; however if you're in the civilised world, you likely have a local Anker distributor, and they also have power banks that support charge-through. Not that it will help you right now in this situation, but just mentioning.

at between positive of cell to board positive

Far easier on the negative side; just cut the long steel wire and insert a fuse or a really thin piece of wire (0.1mm is THICK, you need 0.07 for 1-1.5A)

Neil Ahmad A Blue SMD LED would light up. A Red LED is either fully, all the time, lighting up or flashing while charging. ☺

But can you give a link where you bought it?

Bartosz Olszewski I bought a case fitting two batteries. Also a pair of 3000mAh batteries. I'm waiting to arrive to make myself a little powerbank. :)

Tou were out of luck; it may hapen but usually they works; and price is 0.8-0.99$ on aliexpress

Adrian Andronache Am luat una pt doua baterii (design similar cu cea pt o singura baterie) 4.5 lei.

Da, si eu am cumparat mai multe modele, aveam o multime de 18650 de la doua baterii mari de laptop, cam 60% capacitate, si era pacat de ele. Am luat chiar un model cu 8 spatii, are 2 iesiri (legate in paralel) si reuseste sa scoata 2.1A (si are si 2 intrari de incarcare); a costat cam 4.2$.

Why couldn't I charge Li-Ion batteries?

Nope. Older powerbanks in this style use the MP3401, newer ones (like the ones I just bought for 1.59eur with "2600mAh" cells (tested about 750mAh)) use the slightly improved MP3501 which turns off at lower cell voltage of 2.65V rather than 3.1V of the MP3401, so it uses the battery more efficiently and runs for longer. The MP3501 also seems to be a bit smarter when charging "dead"/over-discharged cells. It'll try charging ANY cell connected to it with 30-50mA till the cell voltage reaches 2.85V, then it blasts it with up to 1A (if the USB source can supply it), slowly lowering charge current in 50-100mA steps till it's full. If the cell voltage doesn't rise to 2.85V (bad cell), it stays at 30-50mA for a while and then just turns off. I've actually stuck batteries scavenged from 8+ year old laptop battery packs into these MP3501 based powerbanks. The cell voltage immediately went up and they charged and revived just fine. The cells were light blue Panasonic CGR18650C rated 2150mAh that were sitting at 0.4-0.9V. They charged just fine, didn't get warm and after a few cycles measured between 1800-1900mAh. Not great but certainly better than the pointless 750mAh ones that came with the powerbanks. Plus they were free :)

Knaeckebrotsaege Wow! Thanks for the information! :) Can you send me a link about cheap 1x18650 power bank with MP3501 chip?

I bought mine on ebay germany and the specific seller I bought mine from is no longer selling them because he got tons of negative feedback (rightfully so) for selling these as 2600mAh even though the completely anonymous (zero markings) 18650's in them turned out to be 700-800mAh. They were the generic brightly colored plastic case single cell ones like shown in this video, but the case was matte-textured (nowhere near as shiny looking as the one in the video) and the embossed "POWER BANK" and the text around the plugs is of higher quality (much clearer, as if the one in the video used a worn-out mold or crappy plastic for the case) I've personally seen those with 5 different controllers now. MP3401 and MP3501 (also clones labeled as SY3401/SY3501), Hotchip HT4928S (junk, turns off VERY early and just 800mA max output), XHR1808 and one with a PCB that is 100% identical to the one with the 3401 and 3501 chips but the chip is completely blank/no markings at all. Which one you get seems to be a complete gamble...

he said in the video that there is no protection circuit on the battery cell