Test/review of Golisi i4

[HKJ]

[size=+3]Golisi i4[/size]

This is a simple four slot charger from Golisi with nice display.



It arrived in a black very stylish cardboard box, there is some specifications on the back.

The total contents of the box was the charger, the bag, a usb cable and a instruction sheet.

The charger is usb powered and can use up to 2A.

The user interface is a single button and a small display.
The button is used to change the readout between volt, mAh, and time. It will not change charger current.

All segments on the display.

Charger is idly without batteries.

The 3 different readouts: Voltage, capacity and time. The % sign will flash while charging.



On the bottom of the charger there are specifications.

The slots uses the classical slider construction and it works fine.
The slots can work from 32 mm to 70.4mm, this means most batteries, except protected xx700 size.

Due to the 1A current with one or two batteries in the charger it is not very good for smaller LiIon batteries.
The charger can handle 70 mm long batteries including flat top cells.




[size=+2]Measurements[/size]

• Last slot will charge a single LiIon with 2A, all other slots with 1A
• One or two LiIon batteries will be charged with 1A, 3 or 4 with 0.5A
• NiMH will always be charged with 0.5A
• Idle current is about 6mA from usb
• Discharge LiIon battery with 3mA when not connected to power.
• Discharge NiMH battery with 1mA when not connected to power.
• When power is connected with a full battery, it will charge with about 0.5mA.
• Below 0.3 volt the charger will report error
• Below 2.1V the charger will assume NiMH else LiIon
• Below about 0.7 volt the voltmeter is not very precise.
• Display turns off after 30 seconds.
• Voltmeter is within 0.01V
• Voltmeter stops updating when charging is stopped and will not show above 4.20V
• Charger will not restart when voltage drops.
• It will restart charging on reinsertion of the battery or power cycling.

[size=+1]Charging LiIon[/size]

Charge current is 0.5A to 2A for LiIon, depending on slot and number of cells.

This is a CC/CV charge curve with about 110mA termination current, as most chargers the change from CC to CV is fairly soft.
With one battery the current is 1A, except slot #4.
Display shows 3088mAh in 3:53

The two next slots are similar.
Display shows 3015mAh in 3:55 and 3095mAh in 3:23

The 2A slot is not really 2A, but starts at 1.5A, then drops to 1.3A. Termination current is the same 110mA.
Display shows 3109mAh in 3:23

A high current cell do not change that charge curve.
Display shows 2985mAh in 2:58

Two other cells looks similar.
Display shows 2566mAh in 3:11 and 2759 in 3:32

The older cell reach CV phase quickly, as expected.
Display shows 1974mAh in 4:18

With two cells the charger was supposed to use 1A, but it drops to 0.5A charge current.
Display shows 3225mAh in 5:44 and 3155mAh in 5:34

With four cells it is down to 0.25A charge current, not very impressive. The capacity readings also looks a bit on the low side.
Display shows 2742mAh in 14:07 for slot #1
Display shows 2797mAh in 14:17 for slot #2
Display shows 2890mAh in 14:45 for slot #3
Display shows 2788mAh in 14:17 for slot #4

Using my own USB cable and a 5.2V supply it looks much better, here it maintains 0.5A without any trouble and the capacity readings are a bit on the high side.
Display shows 3224mAh in 6:39 for slot #1
Display shows 3204mAh in 6:37 for slot #2
Display shows 3268mAh in 6:47 for slot #3
Display shows 3232mAh in 6:41 for slot #4

What about a really weak supply or long cable (My cable + 0.5ohm). The charger charges with about the same current as with its supplied cable, but the capacity readings are even lower.
Display shows 2378mAh in 13:57 for slot #1
Display shows 2358mAh in 13:48 for slot #2
Display shows 2470mAh in 13:57 for slot #3
Display shows 2659mAh in 13:39 for slot #4

M1: 29.4°C, M2: 30.3°C, M3: 30.1°C, M4: 29.0°C, HS1: 37.1°C
I did charge with 0.5A here and it stays very cool.

HS1: 35.8°C

The charger needs about 7 seconds to initialize.

This charger will not lock up with unstable voltage, but a low voltage will affect the charging as can be seen above.



[size=+1]Charging NiMH[/size]

Charge current is 0.5A for NiMH

The charge curve looks nice with a -dv/dt termination and no trickle charge.
Display shows 1926mAh in 4:34

The other slots looks similar.
Display shows 1905mAh in 4:31
Display shows 1933mAh in 4:35
Display shows 1877mAh in 4:27

This is a voltage termination.
Display shows 2346mAh in 5:33

Here it uses a -dv/dt termination
Display shows 2467mAh in 5:51

And I have no idea what it do here. The termination is too early.
Display shows 2010mAh in 4:46

The AAA is handled nicely
Display shows 728mAh in 1:43

Same with the full battery.
Display shows 217mAh in 0:31

And there is no problem with four batteries.
Display shows 1975mAh in 4:41 for slot #1
Display shows 1915mAh in 4:32 for slot #2
Display shows 1961mAh in 4:39 for slot #3
Display shows 1933mAh in 4:34 for slot #4

M1: 30.9°C, M2: 32.8°C, M3: 33.0°C, M4: 31.7°C, M5: 33.8°C, HS1: 34.2°C

NiMH needs about 5 seconds to initialize.

With NiMH it also handles unstable voltage nicely.



[size=+2]Conclusion[/size]

The charger is good for 18650 and larger LiIon batteries and it can also handle NiMH, but it is not fast when charging four batteries.
For fastest speed and most reliable capacity measurement it is best with a short thick USB cable and a USB supply with at least 5V (5.2V is better).



[size=+2]Notes[/size]

The charger was supplied by Banggood for review.

For the testing I used the supplied USB cable connected to a USB socket with exactly 5V

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

 

[alabamaXL]

Thanks for these reviews. Very helpful stuff. Any chance of you doing more detailed reviews of some of the balance circuit capable hobby chargers or any of the DIY battery analyzer/charger options? I'm interested in both scavenging batteries from dead packs and resuscitating/rebuilding computer and tool batteries l, both for original intended use and as emergency power supplies, and curious about all of the equipment out there that I'll never likely be able to afford

 

[HKJ]

Until now I have avoid doing reviews of hobby charger, because they are very complex.

I have reviewed a few DIY electronic loads, but mostly for USB applications.
Here is one more universal type: https://lygte-info.dk/review/Review Electronic load 60W UK.html

 

[alabamaXL]

Thanks, I'll check out that link. I'm trying to pick out a does everything machine or build one for using with larger battery packs with multiple cells and balancing. I might just have to suck it up and buy one based on specs and hope that it lives up.

what are you using for a digital oscilloscope to make the graphs? I have a relatively primitive, but nonetheless capable unit that I got for characterizing loudspeakers, I think I'll be able to hook it up to measure charge/discharge characteristics, but I'm interested in what you're using, since it seems to work well.

 

[HKJ]

what are you using for a digital oscilloscope to make the graphs?

As oscilloscope I use a Pico scope, it is not exactly cheap and I do not use it for charge/discharge curves. There I use some software to record a CSV file from the testing equipment and then use a program based on JFreeChart to convert the data to curves.