The charging current is selectable fot 3.6V Li-ion: 0.25 A, 0.5 A, 1 A, 2 A, 3 A. It’s not 3A per channel (it’s limited to 1A when there are 4 channels in use). The VX4 lowers the charging current as the voltage gets closer to 4.20V. I noticed charging terminate at 4.16V. We’ll soon find out when testing is complete…
The charging current is 0.5A for 1.2V Ni-MH.
The Grade mode has a 0.3 A discharge current for 1.5V Li-ion and 3.6V Li-ion. This could be pretty slow when grading a 6000mAh 26650 cell.
There is USB-C input. 12V 1.67A USB-C PD is recommended. The charging current might be limited otherwise.
Interested to see your tests. I have one on its way for a review, but I’ll link to reviews with more detailed technical tests than I’m able to perform.
The VX4 spent 5 minutes 20 seconds charging the 1.5V Li-ion cell before it started discharging.
I had fully charged the cell in the VX4 in another room about 15-30 minutes earlier. I moved the charger and set it up to monitor with two Zoyi ZT-300AB digital multimeters.
The XTAR VX4 continued to discharge and charge the protected XTAR 16340 cell.
I suspect that the protection circuit of the cell may have Over Voltage Protection (OVP) where it temporarily cuts out at around 4.21V. The XTAR VX4 stops charging the cell. OVP of the cell resets. The XTAR VX4 detects the cell as a newly inserted cell and then it repeats Grade mode.
in a video I just saw, different chemistries were “graded” = capacity tested at the same time in the VX4 and all ended up with a “done” in the display …
the 1.5V Li-Ion and an NiMH were ready earlier and remained at the status “done”, while two 3,6V Li-Ion were charged for another 1 to 1.5 hours or so …
so there was no start of a new “Grade” cycle …
in case of TimMc’s experience there must have been a malfunction, for what reason ever …
