Charger Klarus CH4s

DSC_0930

DSC_0932 DSC_0931

Klarus is mostly known for their flashlights, but they do also sell some chargers. Here I am looking at a 4 channel universal charger that shows how much capacity that is charged into the batteries.

DSC_0924 DSC_0925DSC_0926 DSC_0927

I got the charger in a retail box from a gearbest.

DSC_0928

The box contained the charger, a mains cable and a instruction sheet.

DSC_0933

The charger has both a mains power input socket and a micro usb power input socket.
During my test the micro usb socket broke loose.

DSC_0965

During power on the charger will show all segments on the display.

DSC_0966

Here I have loaded the charger with some batteries, the charger will automatic select NiMH/LiIon chemistry, but LiFePo4/3.7V/3.8V must be selected manually with the mode button. Default is 4.2 volt LiIon (3.7V on display).
The mAh display shows how many mAh is charged into the battery.

DSC_0934

There is two buttons, one to select battery chemistry (MODE) and one to select slot.
When the charger is loaded with batteries the MODE button will select chemistry for all batteries at once. To select chemistry for individual batteries press the SLOT button (Very good functionality).
When the charger starts charging the selection is locked for that battery, to change it the battery must be removed and inserted again.

DSC_0935 DSC_0936

The charge uses the typical slider construction with a metal rail and it works very well from about 30mm to 71mm, i.e. the charger can handle just about any protected 18650 and 26650 cell.

supportedBatteryTypes

supportedBatterySizes DSC_0954 DSC_0955 DSC_0956

DSC_0957 DSC_0958 DSC_0962 DSC_0963
DSC_0959 DSC_0960 DSC_0961

The charger can handle 71 mm long batteries, including flat top cells.
The minimum charge current is 0.5A, this is on the high side for 10440 cells.



Measurements

Charging LiIon 4.2V

Klarus%20CH4s%20(PA18650-31)%20%231

This is a nice CC/CV charge curve with 100mA termination.
Display shows 2924mAh

Klarus%20CH4s%20(PA18650-31)%20%232

The second slot only charges with 0.5A and uses the same 100mA termination. The lower charge current will make it slower, but also useful for smaller batteries.
Display shows 2816mAh

Klarus%20CH4s%20(PA18650-31)%20%233

Klarus%20CH4s%20(PA18650-31)%20%234

The two last slots looks like the two first.
Display shows 2757mAh and 2880mAh

Klarus%20CH4s%20(SA18650-26)%20%231
Klarus%20CH4s%20(PA18650-34)%20%231

2600 and 3400mAh cells also looks fine.
Display shows 2578mAh and 3120mAh

Klarus%20CH4s%20(BE18650-26)%20%231

This older 2600mAh cell do not look as perfect, the voltage is a bit high during the charge and the termination is a bit early. This is nothing serious, but could be better.
Display shows 2297mAh

Klarus%20CH4s%20(AW18350-IMR)%20%232

Another old cell, again the charger curve is imperfect.
Display shows 611mAh

Klarus%20CH4s%20(KP14500-08)%20%232

This cell is newer and the charge curve looks much better.
Display shows 717mAh

Klarus%20CH4s%205V%20(4xPA18650-31)

Using the usb power input was rather slow. The problem is voltage drop in the cables, this charger needs 5V or a bit more.

Klarus%20CH4s%205.2V%20(4xPA18650-31)

Increasing my power supply to 5.2 volt did help, but I did not reach full charge speed. It do even reduce charge rate when battery voltage increase and the charger needs more power.
Display shows 2916mAh, 2883mAh, 2872mAh, 2644mAh

Klarus%20CH4s%20(4xPA18650-31)

Using mains voltage is much better, but current is a bit lower than for a single cell.
Display shows 3057mAh, 3021mAh, 3086mAh, 2946mAh


Temp2275

M1: 34,8°C, M2: 37,6°C, M3: 38,6°C, M4: 36,6°C, M5: 49,0°C, M6: 48,5°C, M7: 51,4°C, HS1: 61,4°C
Batteries are not heated much during charge.

Temp2276

M1: 34,7°C, M2: 37,5°C, M3: 38,2°C, M4: 36,4°C, M5: 48,6°C, M6: 52,8°C, HS1: 63,9°C


StartupLiIon1

StartupLiIon2

The charger is fairly slow to start because it waits for user input.



Charging LiIon 3.6V (LiFePo4)

Klarus%20CH4s%20(18650-LiFePO4)%20%231

A good LiFePo4 charging.
Display shows 1190mAh


Charging LiIon 4.35V

Klarus%20CH4s%204.35V%20(LG18650-30)%20%231




Charging NiMH

Klarus%20CH4s%20(eneloop)%20%231

This looks like a nice -dv/dt charging.
Display shows 1654, this is significantly lower than my curve shows.

Klarus%20CH4s%20(eneloop)%20%232

With the lower charge current the -dv/dt charging can be slower to terminate.
Display shows 1753

Klarus%20CH4s%20(eneloop)%20%233

This time it terminated perfectly.
Display shows 1517

Klarus%20CH4s%20(eneloop)%20%234

The last channel did also terminate perfectly.
Display shows 1774

Klarus%20CH4s%20(eneloopPro)%20%231
Klarus%20CH4s%20(powerex)%20%231

Higher capacity with 1A charge current, the termination works perfectly.
Display shows 2239 and 2169

Klarus%20CH4s%20(eneloopAAA)%20%232

It looks like the charger stops slightly premature on this AAA cell.
Display shows 502

Klarus%20CH4s%20full%20(eneloop)%20%231
Klarus%20CH4s%20full%20(eneloop)%20%232

Detecting a full cell depends on charge current, it is faster with 1A than with 0.5A

Klarus%20CH4s%205V%20(4xeneloop)

NiMH needs less power and less voltage than LiIon, but it is not possible to see the charge current on the above chart.

Klarus%20CH4s%205V%20(4xeneloop)a

Same as above, put with the input current removed. The charge current is about 0.5A for all four batteries, there are no problems with voltage drop from the usb power supply.
Display shows 2093, 1955, 1787,2713 (Oops, the last one did not terminate).

Klarus%20CH4s%20(4xeneloop)

There is not much difference between mains power and usb power when charging NiMH.
When a cell is finished there is a bit more current to the other cells.

Temp2292

M1: 34,4°C, M2: 35,7°C, M3: 35,8°C, M4: 34,7°C, M5: 39,9°C, M6: 38,9°C, M7: 43,8°C, HS1: 50,4°C
The batteries are not heated much during charge.

Temp2295

M1: 33,7°C, M2: 34,8°C, M3: 35,5°C, M4: 34,0°C, M5: 41,9°C, HS1: 49,5°C

StartupNiMH1
StartupNiMH2

The charger is fairly slow to start because it waits for user input.

chargeNiMH

With NiMH the charger stops at regular intervals to measure voltage.


Testing the mains transformer with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.



Conclusion

When the charger is turned off it looks like something I have seen before, but display and functions are significantly different.
I like the capacity display, but it is on the low side for NiMH.
The support for 3 different LiIon types is also very nice and the selection function is good to use.
LiIon has a good charge curve, except on old cells.
NiMH works fine at 1A, but need better termination on 0.5A, I am a bit worried it might miss termination on some cell when using 0.5A.

There is a lot to like about this charger, but due to the above issues, it is just below what I will call good, i.e. acceptable.



Notes

The charger was supplied by Gearbest for a review.

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