Loads Li-Ion very good, but the capacitance measurement is very inaccurate, practically unusable

Good workmanship. Slide running clean.
The LCD has a very limited viewing angle, the tiny icons are nothing for Altersweitsichtige. But goes.
The beeper is incredibly loud. Screwed onto Tesa soundhole: better. You could also increase resistance R43.
Charge current and charge voltage are per shaft can be adjusted separately. Prima thing.
The 4 slots are also circuitry separated, ie completely independently.
The circuit is the Foxnovo F-2 is very similar, but he has not the problem at too low operating voltage. He still runs flawlessly with 8V.

He invites well and accurately to end voltage. LiFePO4, 4.20V, 4.35V. Since there is nothing to complain about. NiMH I have not tested.
4x 1A charging current is not a problem.
Four 26650er easily fit inside.
Also for long-protected battery has enough space.
It has no fan, although provided in the housing space for a 35x35x10er (but no hookups).

The charging current is set precisely. It is digitally controlled (microcontroller).
More surprising is that the measured charge is completely off the mark, which is indeed covered by the same microcontroller via the same analog input. Perhaps a software bug (rounding when adding up the current sample).

Example: Loading an empty 26650ers with 1A charging current (measured: 1040mA)
Display after 30 minutes: 422mAh (instead 502mAh)
Display after 60 minutes: 844mAh (instead 1040mAh)
Display after final charge: 4548mAh (correctly would be approximately 5200mAh)
Unloading (with 0.5A to 2.7V): 5634mAh (instead 5200mAh)

In other cells (NCR18650B, NCR18650BE, LG ICR18650-E1 4.35V) it was no better.

The charge measurement is thus practically unusable. And for a simple 4-way loader 90 then too much (now even 113, and this is certainly due not only Mr. Draghi).
That is why I have just submitted an Amazon return request.

Discharge does not occur at DC, but with 63kHz PWM over approximately 0.8 ohms of resistance, duty ratio is controlled so that the average discharge current is about 470 mA.