Test/review of Charger LiitoKala Lii-202

Charger LiitoKala Lii-202











LiitoKala got known for a analyzing charger, but has since made many other chargers. This is a usb charger that can charge a wide selection of batteries and it can also work as a power bank.







It arrived in a plastic bag







But it did include a usb cable and an instruction sheet in addition to the charger.







The charger has a micro usb input and a full size usb output for the power bank function.

The charger needs a 2A usb power supply/charger to work at full speed.







The user interface is a couple of leds and a single button.

A fast press on the button will select battery type, when a battery has just been put into a slot.

A long press (2 seconds) will change current at any time.







There is 4 blue leds for each slot, they are used to show charge state and when selecting battery type.







One 3.7V LiIon (Charge to 4.2V) and one NiMH battery in the charger, ready to charge with 0.5A







Charging, the blue leds are animated.







The slots uses the classical slider construction and it works fine.



The slots can work from 33 mm to 70mm. This means that very long protected 18650/26650 batteries will not fit in the slots.















The charger can handle 70 mm long batteries including flat top cells.







Measurements

  • When not connected to power it will discharges with less than 0.1mA.

  • On the power bank slot it will discharge with about 0.15mA (45mA while indicating capacity).

  • When power is connected with a full battery, the charger will charge with 0.15mA

  • Below 0.1V the charger will not detect a battery, but will charger with about 3mA

  • Between 0.2A and 1.5V the charger assumes NiMH

  • Between 1.6V and 2,1V the charger will not recognize a battery, but charges with about 2mA

  • Above 2.2V the charger assumes LiIon

  • Charger will not restart when voltage drops.

  • It will restart charging on reinsertion of the battery or power cycling.

  • Usb input power consumptions when idle without batteries is 34mA, with batteries about 60mA


Charge LiIon 3.7V setting (4.2V charge voltage)



The charger uses a CC/CV charge algorithm with about 50mA in termination current, this is a good charge.



Second channel looks the same.





No real surprise with the low/high capacity cells. The 3400mAh cell charges a bit faster than the 3100mAh cell, because the CV phase is shorter (The length of the CV phase will depend how worn the battery is).



This old battery needs a very long CV phase, and is charged fine.



The charger profile is just as fine at 0.5A and the termination current is the same.





The two small cells are also charged fine, there is some sort of hick-up while charging the 18350, but it do not affect the final result.



Charging two cells at the same time means that the charger needs 2A from the usb input.



Simulating a weak power supply by adding 0.5ohm in series with it slowed down the charging considerable, but did not prevent the charger from doing a good job.



M1: 36,9°C, M2: 36,7°C, M3: 42,8°C, M4: 42,9°C, HS1: 53,8°C
I can spot something warm in the charger, but not anything hot and the batteries is not very warm.



M1: 36,4°C, M2: 35,4°C, M3: 46,5°C, HS1: 57,3°C



The charger need some time to start, most of the time is used to wait the user to select another battery type.



When changing current the charger always start from a low current and slow increase it to the selected level.



Charge LiIon 3.8V setting (4.35V charge voltage)



No surprise with the 4.35V charge, it looks fine.



Charge LiFe 3.2V setting (3.6V charge voltage)





The two LiFePO4 charges also looks fine.



Charge NiMH 1.2V



With NiMH the charger turns off current to measure the voltage and will terminate on voltage without doing a top-off charge. This means the batteries will not be fully charged, but they are fairly close.



The second channel looks the same.







On the 3 high capacity batteries there is a small temperature increase at the end, i.e. they are very close to being fully charged.



Termination works fine at 0.5A



The AAA is charged fine.



As usual voltage termination is fast to stop when the cell is full.



The charger maintain the same charge current with two cells.



M1: 37,7°C, M2: 38,9°C, M3: 42,8°C, M4: 42,2°C, HS1: 56,0°C



NiMH needs the same time to start as LiIon, but it is not possible to select battery type.



With NiMH the current change is more abrupt.



Usb output
  • Usb output is coded as Apple 1A

  • Usb output will turn off after 10 seconds with less than 38mA load.

  • On the power bank slot it will discharge with about 0.15mA (45mA while indicating capacity).





The usb output can deliver 1.2A before the voltage starts dropping, this is good for a 1A output.



With a 0.5A load the usb output looks good for about 3 hours.



But at 1A load the usb output do not really work, the converter cannot handle a partically discharged battery.



The noise is 266mV rms and 2285mVpp, this is bad.



The noise is 269mV rms and 2197mVpp. The noise looks different but the actual noise level is about the same.



Conclusion

This charger is good at LiIon and fairly good at NiMH and the possibility to select multiple LiIon voltage makes it very versatile.

The power bank function is not very good, it uses an old coding and cannot deliver full current with a partial discharged battery, in addition to this the noise is very bad.

I.e. it is a good charger, but do not buy it for the power bank function.



Notes

The charger was supplied by Gearbest for review.

Here is an explanation on how I did the above charge curves: How do I test a charger

Thanks for the review HKJ! That is a very nice CC/CV curve and excellent termination current.

Since the powerbank function is not very useful, by removing the USB port and expanding the hole I think there is room for a voltmeter like we have done with the Li-100, and even a small switch to read between the two batteries.

Thanks HKJ.

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?