Charger PSPower MT4000





This charger is a NiMH and LiIon analyzing charger, it also has a usb power output.






I got the charger in a cardboard box with specifications on.



The pack included the charger and a power supply, the manual was not ready yet.



The charger has a 12V input for the power supply and a usb output.



The charger has a lcd display to show functions and charge status and 7 buttons.
The 1-4 buttons is used to select a single slot, where mode and current can then be specified.
The MODE button is used to charge or test, when used without a number key it will set for all slots, if a number key is pressed first then only the mode for that slot is changed.
The CURRENT button will select current for the slot that has just received a battery or has just changed mode.
The DISPLAY button selects what to display.



The display can show mA, mAh, volt, hours and ohm, use the DISPLAY button to select.



The charger has the usual sliders and they can handle from 32mm to 70.3mm, this means most cells, except the longest protected 18650 and 26650 cells.









Measurements charger

• The charger will discharge LiIon batteries with about 0.3mA when not connected to power.
• When power is connected with a full LiIon battery, the charger will charge with 0.2mA
• Below 0.1V the charger will not detect a battery, but will charger with about 1mA with 0.2A pulses
• Between 0.1A and 1.5V the charger assumes NiMH
• Between 1.6V and 2.2V the charger will not recognize a battery.
• Above 2.2V the charger assumes LiIon
• Voltmeter is usual within 0.01 volt
• Voltmeter do not show precise values below 0.8V
• Charger will not restart when voltage drops.
• It will restart charging on reinsertion of the battery or power cycling.
• Power consumption when idle is 0.55 watt (0.25 watt of this is used by the power adapter).

Charge LiIon

In charge mode the current must be selected between 300mA, 500mA, 700mA and 1000mA



This is a good CC/CV charge curve with termination at about 100mA.
The display shows 2402mAh in 3:27





The other 3 channels also looks fine.
The display shows: 2436mAh in 3:30, 2524mAh in 3:31 and 2516mAh in 3:36




No problem with different capacities.
Display shows: 2157mAh in 3:02 and 2736mAh in 3:36



The old cell is also handled fine.
Display shows: 1953mAh in 3:33



There is no problem with using the lowest current setting, except the termination current stays at 100mA.
Display shows: 2493mAh in 8:59




The small cell is charged nearly full, but the 100mA termination is again a slight problem (This issue exist on many chargers).



The charger handles 4 cells at full current.



This requires about 1.8A from the power supply (It is rated for 3A)



M1: 43,1°C, M2: 44,3°C, M3: 43,3°C, M4: 41,0°C, M5: 50,1°C, M6: 59,6°C, HS1: 71,6°C
Temperature is within acceptable limits.



The charger is fairly slow to start, this give the user time to select mode and current.




Test LiIon

In test mode the current must be selected between 300mA, 500mA, 700mA and 1000mA. The selected current is used for charging, discharging will be done at 250mA or 500mA. The charger first charges the cells, then discharges it and finally chargers it again. Display will show discharged current.



The charger will discharge to about 2.8 volt when testing, there is a short pause before the cell is charged again. This test takes about 13 hours with my cells.
Display shows: 2686mAh in 5:37





The other slots looks the same.
Display shows: #3: 2769mAh in 5:47 and #4: 2676mAh in 5:38



There is no problems with time limits, it can also be done at the lowest setting (But it requires some patience, it took 30 hours).
Display shows: 2707 in 11:19



With four cell the temperature is rather high during full current discharge.



M1: 55,2°C, M2: 61,4°C, M3: 61,9°C, M4: 57,5°C, M5: 49,9°C, M6: 54,2°C, M7: 41,8°C, HS1: 69,0°C
The cells gets rather warm during test, probably because the discharge resistors are placed under the cells.



Discharge is done without pulsing.



Charge NiMH

In charge mode the current must be selected between 300mA, 500mA, 700mA and 1000mA



With NiMH the charger will terminate on voltage and there is no top-off charge, i.e. the cells will be slightly below maximum capacity.
Display shows: 1682mAh in 1:53





The other slots looks the same.
Display shows: 1665mAh in 1:52, 1727mAh in 1:56, 1739mAh in 1:57



This cell is obvious too old and the charger cannot handle it.




The other high capacity cells is handled fine. The termination voltage is fairly precise for these cells, there is a small temperature increase.
Display shows: 2372mAh in 2:39 and 2341mAh in 2:37



With voltage termination it is also possible to terminate at very low charge rates.
Display shows: 1623mAh in 6:04



There is no problems with the AAA cells.
Display shows: 642mAh in 1:27



Voltage termination will terminate fairly fast on a full cells.
Display shows: 68mAh in 0:04



There is no problem charging four cells at full current.



About 1A is needed from the 12V input.



M1: 40,7°C, M2: 42,4°C, M3: 41,3°C, M4: 38,8°C, M5: 47,1°C, M6: 50,3°C, HS1: 66,0°C
Temperature is acceptable.



The charger is fairly slow to start, this give the user time to select mode and current.


Test NiMH

In test mode the current must be selected between 300mA, 500mA, 700mA and 1000mA. The selected current is used for charging, discharging will be done at 250mA or 500mA. The charger first charges the cells, then discharges it and finally chargers it again. Display will show discharged current.



The cell is discharged to about 1 volt and after a short pause charged again.
Display shows: 1955mAh in 3:33





Display shows: 1902mAh in 3:28, 2031mAh in 3:42 and 1911mAh in 3:29



It is also possible to do the test at lowest current without hitting any time limites.
Display shows 2063mAh in 7:31



Here I run the test on four cells at once.
Display shows: 1933mAh in 3:31, 1927mAh in 3:30, 1985mAh in 3:37 and 1900mAh in 3:27



M1: 39,0°C, M2: 41,0°C, M3: 41,5°C, M4: 40,2°C, HS1: 46,1°C
When discharging NiMH the power is much lower and the cells stays cool enough.



Discharge is done without pulsing.



Usb output

• Usb output is coded as Apple 2.1A, but the coding may be out of tolerance.
• It is not a power bank

The usb output can deliver 1.1A, that is fine for a 1A rated output. The efficiency is rather low.



The output can deliver 1A for one hour.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.



M1: 40,3°C, M2: 37,3°C, M3: 40,5°C, HS1: 49,1°C
It gets a bit warm, but nothing problematic.



M1: 35,9°C, M2: 32,6°C, HS1: 46,2°C



Noise is 19mV rms and 99mVpp



Noise is 17mV rms and 88mVpp, this is very low noise.


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



Conclusion

The charger is good at charging both LiIon and NiMH, but with small LiIon cells and some NiMH cells you will get slightly below maximum capacity (This is fairly common on many different chargers).
The analyzer/test function can be used to keep track of cells, but precision is not that precise when charging.

The usb output has a misleading/wrong coding, but is a good 1A usb supply.



Notes

The charger was supplied by Power Advanced Limited for review.

Here is an explanation on how I did the above charge curves: How do I test a charger
Read more about how I test USB power supplies/charger