Charger Xtar WP2h

DSC_8039

DSC_8041 DSC_8040

This is the latest version of the WP2 charger. The other versions I have tested are WP2 II 2014, WP2s, WP2 II and WP2, most of them has been good chargers.
This charger has a few significant updates: It can do 3 currents and 3 voltages. This makes it suitable for many types of LiIon batteries. It can also be used as a usb power bank.


DSC_7986 DSC_7987 DSC_7988 DSC_7989

It comes in a cardboard box with a lot of specifications on.

DSC_8038

The box contains the charger, a power supply, a car adapter (This might be optional), a warranty card and a instruction sheet.

DSC_8042

The charger has a 12V input and a usb output.

DSC_8029 DSC_8043

The user interface is 6 leds, a button and a 3 position slide switch.
3 of the blue leds is used to show voltage and current selection, the last blue led is on when usb output is on.
The red/green leds show charger status: Red=Charging, Green=Not charging, flashing red=error.
The button is used to select current.
The slide switch is used to select voltage.

DSC_8046 DSC_8047

The slots uses the usual slider system and works fine, it can handle batteries from 31.8mm to 71.0mm.

supportedBatteryTypes

The sliding switch on the charger is used to select nominal voltage.

supportedBatterySizes DSC_8030 DSC_8031 DSC_8032
DSC_8033 DSC_8034 DSC_8035 DSC_8036

The charger can handle 71 mm long batteries, including flat top cells.



Measurements


Xtar%20WP2h%201A%20(PA18650-31)%20%231

The charger does a nice CC/CV charge with a 100mA termination current.

Xtar%20WP2h%200.5A%20(PA18650-31)%20%231

At 0.5A charge current the termination current is down to about 50mA.

Xtar%20WP2h%200.25A%20(PA18650-31)%20%231

At 0.25A charge current it is down to about 25mA, this is very nice and means the charger will work well when charging smaller cells.

Xtar%20WP2h%201A%20(BE18650-26)%20%231
Xtar%20WP2h%201A%20(PA18650-34)%20%231

No surprice with different capacity. My 2600mAh cell enters the CV phase a bit early, this is both because it a 2600mAh cell and because it is a bit old.

Xtar%20WP2h%201A%20(PA18650-31)%20%232

The second channels looks like the first.

Xtar%20WP2h%201A%20(AW16340-IMR)%20%231

My old 16350 is charged fine, even at 1A.

Xtar%20WP2h%200.25A%20(AW16340-IMR)%20%231

Reducing the current to 0.25A will fill a bit more enegy into the cell, due to the lower termination current.

Xtar%20WP2h%200.5A%20(AW18350-IMR)%20%231
Xtar%20WP2h%200.5A%20(KP14500-08)%20%231

The two mid sized batteries is charged fine with 0.5A.

Xtar%20WP2h%201A%20(2xPA18650-31)

Doing two batteries at once does not affect the charge speed.

Xtar%20WP2h%201A%2012V%20(2xPA18650-31)

The charger uses slightly below 1A on the 12V input when charging two batteries with 1A each.

Temp1408

M1: 38,6C, M2: 38,2C, M3: 47,5C, HS1: 65,5C
As usual chargers gets very hot inside, this charger keeps an acceptable temperature on the batteries.

Temp1409

M1: 38,6C, M2: 37,8C, M3: 47,0C, HS1: 48,8C

Startup

The charger needs about 8 seconds to reach 0.25A charge current.

Charge

Changing current will slowly ramp up to the selected current.



4.35 volt charging (Switch position 3.8V)

Xtar%20WP2h%201A%20(LG18650-30)%20%231

There is no surprise with 4.35 volt charging, it looks very fine.


LiFePO4 charging (Switch position 3.2V)

Xtar%20WP2h%201A%20(18650-LiFePO4)%20%231

LiFePO4 is also charged correctly.



USB output

Xtar%20WP2h%20load%20sweep

The usb output from the charger is very stable, but not overload protected. Making the above curve did blow the charger.
I.e. do never use a "charge optimizer" on this usb output.

Xtar%20WP2h%20out%205ohm%20(PA18650-31)

Running at the rated 1A load the charger has very good efficiency and maintains the usb output voltage until the battery is empty.

Xtar%20WP2h%20out%2010ohm%20(PA18650-31)
Xtar%20WP2h%20out%2010ohm%20(BE18650-26)
Xtar%20WP2h%20out%2010ohm%20(PA18650-34)

Efficiency is even better at 0.5A load, the runtime will vary with the used battery.

5ohm

The noise is very low with 1A load: 5mV rms and 55mVpp.

10ohm

And about the same at 0.5A load: 5mV rms and 52mVpp.



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



Conclusion

This is a very good universal LiIon charger, it can handle most types and sizes of LiIon batteries.
The usb output is also good, but I am missing an overload protection.



Notes

The charger was supplied by XTAR for a review.

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