I wanted to test the Grading function on a couple of my old LiIon and on an AAA Eneloop Pro that has very low output. I found the operation of the charger very easy to figure out. It detects battery chemistry automatically, and sets the charge rate automatically, both of which work very well.
The charger came with a USB A to C cable, as well as a power block with a USB C port. I used a C to C cable that I already had.
I like that the VX2 Pro offers a Refresh function for NiMh, as well as a Grading function that measures mAh capacity of LiIon batteries. In addition to basic charge and discharge functions, it also has a storage function for LiIon. It is a very full featured package. Recommended. Im very grateful to Xtar for sending me this charger for review.
I loaded a old unbranded 14500, and an old Lumintop 16340 w Mini USB port into the charger, set to the Grading mode. The two separate battery slots operate independently and can be loaded with different battery chemistries, set to different functions such as Grading for LiIon and Refresh for Nimh:
I noted that the Internal Resistance (IR) of the blue 14500 was 51 mΩ, much lower than the IR of the old 16340, whose resistance showed 216 mΩ. I found it useful to see the difference in IR of the two batteries as I suspected for some time that the 16340 was getting past its useful life. Take IR numbers as an approximation, as the results will vary each time the same battery is inserted into the charging slot.
After the charger finished its grading cycle, it indicated that the blue 14500 rated as 850 mAh on the label, now has a capacity of 731 mAh, just 14% lower, and an IR of 51 mΩ. Based on the capacity and IR, the charger confirmed that this battery does not need to be recycled yet. It is still useful to me, especially at the relatively low outputs, that I use, primarily indoors.
The charger indicated that the 16340 has a capacity of 498 mAh, and an IR of 216 mΩ. Its original rated capacity was 700 mAh, so it has lost almost 30% of its capacity. Based on the IR, the charger confirmed that this battery is getting old. However, Im going to keep it a little longer, until it is no longer useful at the relatively low outputs I use indoors.
I then removed the 16340 and used that slot to test the Refresh function on an old AAA Eneloop Pro.
The VX2 Pro at first proceeded to do a Charge cycle on the old Eneloop, it got up to 1.56V and then switched to a Discharge cycle. After which it recharged and then reached the Done stage. The IR indicated 236 mΩ. I removed the battery and tested it in a Thrunite Ti3. The old Eneloop Pro only produced a maximum output of 14 lumens. The Ti3 with a new AAA 1.5V LiIon gives 92 lumens.
The old Eneloop Pro had the same limited 14 lumen output before using the Refresh function in the VX2 Pro. The charger was not able to increase the output of the old AAA Eneloop Pro. I reserve the tired old battery for use at low output indoors.
I really like the versatility of this Xtar VX2 Pro charger (unaffiliated Amazon link), as it works with all of my battery chemistries. I also like that it gives approximate IR for them, and that it estimates the capacity of my LiIon batteries. It is a very convenient full featured package.