I have bought an Xtar MC4 in 2020. I use it for charging unprotected 18650s. End voltage for my cells are mostly around 4.22-4.25V. The charging led remains red sometimes even at 4.27V. I have tested many old/new 18650 cells, various 5V adapters and different charging slots. I suspected it is fake. As you can see in the images, the branding style is different from packaging. But the build quality is too good to be fake. I have also MC1, it charges exactly to 4.19-4.20V. Do you have any suggestions?
Thanks for all the responses. Yes, the cells in that picture are old. But I have tried brand new LG Chem and Sanyo cells also. One of them is below.
My observations are:
0) Charger build quality is very good, no heating, compact, great for camping, I like the charger very much. That’s why i wish it didn’t have this issue.
1) Whatever combination of slots/cells I try, resulting voltages are high, MOST of the time (>4.24V).
2) If I use outer slots, (since they use a higher termination current, i think) the termination voltage is relatively low (4.22-4.25V). For inner slots, any cell may go as high as 4.28V, but they occasionally may also end up as ~4.25V. Btw, after charging, I wait half an hour, but the voltages go down 0.01V at most.
4) I have tried a 5V 3A charger, 5V 2A charger, 5V 850mA charger (for a single cell only). I have tried many high-quality USB cables. Still no change; termination voltages are always high.
5) Most probably the seller won’t accept return. So, I am thinking of getting an Xtar MC2S. I want the charger to be simple, compact, and undercharging. If you have any suggestions, i want to hear them also.