Efest LUSH Q4 Charger 2017





This is a simple quad cell mains powered LiIon charger without any settings.



It arrived in a small cardboard box with specifications on it.



The box included the charger, a mains cable, a warranty card and the instruction sheet.



The charger has a mains socket for power and is universal power (100-240VAC 50/60Hz).



The only user interface is a led light for each channel, white when charging and blue when finished.



Specifications are on the bottom, but not very easy to read.



The slots uses the classical slider construction and it works fine.
The slots can work from 27 mm to 70mm. This means that it will handle most 18650/26650 batteries, except the longest ones.







The charger can handle 70 mm long batteries including flat top cells.
The charger current is on the high side for many regular cells, but fine for IMR batteries



Measurements

• When not connected to power it will discharges with about 8mA.
• Below 0.55V the charger will not detect a battery
• Between 0.55V and 2.8V the charger will charge with about 600mA to 1.2A
• Above 2.8V the charger will use regular charging.
• When one cell is full, the others will be charged with the higher current.
• Charger will restart silent when voltage drops slightly.
• It will restart charging on reinsertion of the battery or power cycling.
• Power consumptions when idle without battery is 0.2 watt

The charger uses a CC/CV charge curve, but has problems terminating the charging. With one battery the current is around 2A, this is rather high for many battery.





All slots works the same.





Other capacities and older batteries is handled the same way.



With two batteries in the charger the current is reduced to less than 1A



With four batteries the current will be reduced to less than 0.5A.



M1: 43,4°C, M2: 48,4°C, M3: 49,6°C, M4: 46,4°C, M5: 59,0°C, HS1: 67,9°C
The two center batteries is a bit warm.



M1: 44,3°C, M2: 44,0°C, HS1: 55,4°C



Sweeping the battery voltage from zero to 4.25 shows charge current at the different charge levels.
I did also add a curve to show how much heat is generated in the charger, most of the time the voltage will be between 3.5V and 4V, i.e. a bit above 4 watt.



The charger is very fast at starting.



The charger will always charge at full current, here I removed batteries during charging and it automatically increased current.


Testing the power supply with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.



Conclusion

The charger uses a rather high current, when charging a single battery, but with four batteries the current is fairly low.

I will rate it as acceptable due to the termination problems.



Notes

The charger was supplied by Efest for review.

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