Charger Leise NiMH 4 slots LS-U401A





I have looked at NiMH batteries from Leise before, this time it is one of their small chargers.





I got the charger in a small brown cardboard box



The pack included the charger, a usb cable and a instruction sheet i Chinese.




The charger is usb powered.





I have not seen the "DISCHG" come on during usage and the charger do not have any buttons.



Charging two NiMH batteries. The batteries are animated when charging.











Measurements charger

• Current consumption when idle is 4mA from usb (Background light off).
• Without power it will discharge a NiMH battery with less than 0.1mA
• The charger will restart when a battery is inserted or power is cycled.

The charger terminates on -dv/dt, but it is slow to terminate, the batteries get fairly warm. After this charging, it uses a high trickle charge of about 70mA.





The 3 other channels looks the same way.



The eneloopPro is charged the same way.



Even the worn down powerex is charged (With more than 5000mAh).



Leise batteries are also charged the same way.



With a single AAA the average current is reduced to 1A, this also includes the trickle charge that is down to 40mA



A full battery gets about 1/3 extra charge before the charger stops.



With two batteries the charger will reduce the average charge current to 1A, but it is still slow to stop.



With four batteries the current is down to 0.5A
In all cases the charger draws about 1A from usb (It is rated to draw 2A).



M1: 46.6°C, M2: 38.6°C, M3: 40.0°C, M4: 49.0°C, HS1: 50.1°C
The charger do not use same charging speed for the cells in the charger as can be seen on the temperature.



M1: 39.6°C, M2: 41.7°C, M3: 42.8°C, M4: 41.3°C, HS1: 45.5°C
Here the charging speed is more balanced.



M1: 32.9°C, M2: 39.1°C, M3: 40.0°C, M4: 34.9°C, HS1: 41.7°C
And now it is the two other cells that need most charging speed.



M1: 70.4°C, M2: 70.4°C, HS1: 81.1°C
During termination the cells get rather warm (They always do that, but above 80°C is a bit extreme).



The charger starts out with a long current pulse, then a rest period, before it goes into regular charging.



With one cell the charger current is about 2A and there is pauses to read the voltage.



With two cells in the charger the current is still about 2A, but the charge circuit is shared between the two slots.



With four cells it maintains the 2A and the time sharing is split on 4 slots.
Notice the noise on the red line, it stops each cycle. This is where the charger checks voltage on all 4 cells.



Trickle charge is a high current pulse at regular intervals.



Conclusion

This charger fills the batteries and then add a bit extra with the slow termination. The cells get warm and it will increase wear slightly on the cells. I am not that impressed with variable charge current from 2A with one cell to 0.5A with four cells, usb has enough power than it could have done 1A always and there is no reason to use a high trickle charge.
The hole in the bottom of the charger makes it easy to push batteries out.

I will rate it acceptable.



Notes

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