Nice review as usual. Too bad the USB port kind of sucks. Everything else looks good.
10x for your effort m8
Something that needs to be mentioned: the charger claims to charge 2 liions at 1 amp each but it doesnt, when 2 batteries are charged at once it charges them at 600ma each
Tested with both Blitzwolf 2.4a USB charger and PC USB 3.0 output, a total of 6 units so far
Not in my test, as can be seen on my curves. It is more like 900mA.
Try a short thick usb cable from the usb power supply to the charger.
Hm…have to try that out- was using their default cables , as long as they provide those its usualy means they should be working as intended
Those default cables are usually pretty lame. Remembered me of this example of “premium” lameness: BlitzWolf® BW-CB6 2.1A Reversible Micro USB 6.56ft/2m Charging Data Cable @Banggood
Sorry fellows, 2,1A through 2 meters of AWG22 wire “round trip” means a whopping 457,28mV drop in the cable itself, and I haven't included plug resistance losses. In no way such a cable can live up to those deceitful claims at 5+V nominal PSU voltage.
That's the reason I built for myself a custom 5' data/power USB cord out of some spare Cat 5e cable.
Cheers ^:)
I bought one of these from Gearbest, and it won’t even pull 1 ampere — even with two 18650 cells! I think the best I ever pulled was around 0.75A, but usually it’s actually only about 1/3 amp!
It also decides that cells are charged prematurely. Especially if a cell gets moved a bit (I often have to reset it then), but it will only charge to about 4.08V even if I don’t touch it.
My single-cell version of this charger actually draws more power! (Works properly and charges fully.) With that one (the 101?), I can draw a full amp.
I’ve even taken apart my Lii-202, looking for connection problems, or anything I might notice. No change. Any ideas? I had a bad experience dealing a very resistant customer service email rep at Gearbest, so I haven’t been enthused about trying to contact them.
By the way: yes, I used good power sources, and specially-selected (and multiple) high-quality USB cables. I have USB power monitoring devices, and compared it with several other working chargers, using the same equipment. It’s definitely the Lii-202.
Thanks HKJ! Looks like a good charger to give to a beginner!
I ordered a Lii-202 for my parents and it too ceases charging early, though not as bad as yours. Right bay stops at 4.12V and left stops at 4.14V.
Maybe quality issues in this early revision? What's up with all of that noise on the USB supply and the inability to deliver full power at low input battery voltage? It worked well on the smaller sibling, you know, so… 
Stick with the known good and easily moddable Lii-100, comrades. I myself have plenty of 2+A 5V PSUs, including a vintage 4-port USB v1.1 hub fed with a 6V 2A linear “brick”.
Cheers ^:)
A usb meter may be the reason it will not charge with full current.
Mmm, just took a quick peek at some old school linear supply smoothing capacitor calculations, and I'd say that a 4700μF capacitor (mod) at the USB output should be plenty to keep the noise under 500mVpp at all times, doesn't it?
Yes, I already know this may sound sort of “wtf” to most end users, but learning is fun.
Cheers ^:)
Maybe, but you cannot use the old style calculations.
The frequency is much higher, this means smaller capacitor.
You need a capacitors with low ESR at the relevant frequency, i.e. a type with low ESR at 100kHz will do.
It will not increase the power of the boost converter, i.e. you will still have problems when the battery voltage is low.
Thanks for the testing, HKJ! Great review as always.
I’m very happy with this charger, bought from Gearbest 2 months ago. Never used the powerbank function, though. But charging it does great.
I took pics of the internals, will upload them soon.
Mine does 2 x 1A very nicely, but it was difficult to find out.
I measured with aluminum foil, cardboard and DMM first, and got very low values. The foil had a strangely high resistance and the DMM added to it. Then I soldered a 10mOhm shunt in both channels and measured the voltage drop: slightly over 1A per channel simultaneously. PSU is the HKJ-approved Enerpower Flypower 2A.
So my charger does a fine Job.
Will start looking into making the target voltage selectable.
From the article, C = Iload / (f × Vpk-pk). After peeking at the graphs, I decided to go with Iload = 1,2A, f = 500Hz and Vpk-pk = 0,5V. This results in… 4800μF. Of course, these calculations may not mean much here and such capacitor may still be oversized, in practical terms. And of course, that won't fix de boost converter design/quality control failure. :FACEPALM:
Are classic (cheapo?) electrolytic caps low ESR in nature? I believe so, or at least should be more than good enough for this and/or fixing noisy driver outputs, doesn't it?
Cheers ^:)
The switcher frequency is probably about 50kHz.
For best result you need a capacitors specified for switcher usage, i.e. low ESR specified at 100kHz. Capacitors designed for 50/60Hz bridge rectifiers or audio applications are not really low ESR types and are not designed for 100kHz.
LiitoKala Lii-202 PCB
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Pass through charging is not working on Lii-202. So usb output is not working if usb input is connected (with or without batteries inserted). Any way to fix this? Like manually connecting usb input contacts (+ and -) with usb output? Any concerns why I should not do that?
Lii202-V7 pcb
10/28/2016
WHat’re the changes to the version v3 ?
Hmm, new ones have problem with low voltage charging in one slot.
One slot is 4.17-4.18V and other is 4.11-4.13V tested on three samples. So they mess something in this new ones in whole batch, does someone else notice this ?