Hi guys!
As it says in the subject I am looking for a compact 2x18650 power bank that has quick charge 3.0. My perfect power bank would be something like the Tomo M2 (which is what I keep in my purse now) but with QC3 so I can get “fast charging” on my Samsung phone. I have looked on eBay and Fasttech, but maybe it doesn’t exist… 
Thanks! 
2x 18650 could probably power qc2 fine but qc3 is 12v so I think you’ll find it doesn’t exist.
LOL well that would explain why I could not find such a thing!
Anything that would be close to my desired spec? Or is anything that is both compact and QC 3.0 not going to take 18650’s?
Thankee!
The problem is not a 18650 not being capable of the power output, there is simply not a market large enough for a manufacturer to invest money to develop a DIY QC3.0 powerbank board + Housing. And even if they did, it probably won’t work as efficiently as finished products. And if they manage to make it work flawlessly, I highly doubt the finished setup will end up being cheaper than a existing product.
BTW most QC3.0 devices are backwards compatible with QC2.0 (5/9/12V) chargers, so I would recommend looking into existing powerbanks that work great and are cheap, like the xiaomi 10,000mah 2. It has one of the best capacity-size ratio, can be found under $20.
Soshine E3S-QC 18650x4 Portable Power Source Bank + Quick Charger 30W:
http://www.soshine.com.cn/a709.aspx
Maybe you can run it with just 2x 18650?
I’d like to see a review of this Soshine E3S-QC DIY powerbank… Not sure if HKJ has it yet…
You would be the first to review it 
HKJ didn’t publish a review yet.
Did you ever find a solution? I’ve been looking for the same for years too. Maybe with 21700 or 20700…I think QC4 should be achievable. This Soshine E3S-QC - I never found a source to purchase it from.
6 years on and I’m not sure if we are actually any better off for a solution!
I received a LiittoKala Lii-MP2 recently and am pretty underwhelmed by it, I’ve filled the case with two (unknown brand but well tested by myself) 3000Mah 18650 cells which should do 5A.
The powerbank will often stuggle to charge my Samsung A55 efficiently (remaining battery % decreases quickly, disconnects and needs to be manually unplugged then plugged in again to resume charging).
I’ve tried a Google pixel 4 and it seems to charge moderately quickly (guessing 45 minutes - 1hr to charge the phone), each percentage drop on the Lii-MP2 results in 1% gain on the phone, so I figure its about 50% efficient(?!) when it’s working correctly…
There are all sorts of these things on Amazon.
But you are going to need 12v plus to power one.
So like 4 cells in series. Or a 12v LiFe,
All the Best, Jeff
Not quite portable in a backpack though… I suspect trying to charge your phone with a tangle of wires, batteries glued on and flashing LEDs on public transport might attract the wrong kind of attention 
AliExpress has some “DIY Powerbanks”, this one is for 3 18650s, but looks like they are all parallel so you could use only 2 as well (sorry for the weird link - can’t get a regular link from the Android app, it’s not a ref link):
If you have a 3D printer and want to tinker and design a case (maybe thingiverse/printables already has one) there also is bare power bank PCBs capable of USB-C PD and Qualcomm-QC4:
Those super cheap 3x18650 DIY power banks have caught my eye, I miss HKJ reviews for stuff like this, I’d like to know the chances of it burning my house down 
I don’t know if this qualifies as a “DIY” power bank, but I just checked the back of my Xtar PB2SL and it does state it supports QC3.0 output. (EDIT: I just now realized that it’s only up to 18 watts.)
Not sure if some of the other Xtar (or similar brands) do support it, but I just checked this one because I had it on hand.
If you are in Europe, it might well be worth it to check Nkon for prices on Xtar chargers, because in general they are significantly cheaper than on Aliexpress, sometimes even with the added shipping costs. (And otherwise you can always include a few extra batteries, to ‘spread’/devide the shipping costs over several items.)
Yeah same, would be nice if someone tested them already. I could order one and tear it down and check, but I have no 18650s for testing 
All my lights are 14500, 18350 or 21700.
I do have that 3x18650 you posted and I could try to make some (decent) pictures if you want me to.
Bought it as an impulse buy when it was only something like € 2,50. Only used it a couple of times and checked (one time) if it didn’t overcharge the batteries, which it didn’t. It’s a pain in the *ss though to get it open, because it has a whole bunch of clips. Certainly not a powerbank where you would regularly swap out batteries.
On the upside: I expected the 8 LED’s to be ugly white, but they were actually warm white (3000-4000K) and whit 3 brightness settings. (Slight PWM on the low and medium mode, no noticable PWM on high, as far as my eyes could tell.)
Because I was bored anyway, I did take it apart and took some quick photos with my phone. Not the best quality, but it should hopefully give an idea. Not much electrical components to be photographed though!
Obviously it’s difficult to follow all the traces on these photos.
