Friends, there is good news. KUNKIN has released a firmware update:
1) The voltage is read by reading one register, and the voltage value is obtained after smoothing and filtering, so there will be no sawtooth shape. The voltage acquisition rate before smoothing and filtering is 470SPS, and the voltage value after smoothing and filtering, the refresh rate is relatively low, it is 10SPS.
2) Instructions to set the battery discharge mode, half-current discharge is enabled and can be saved
I got a new KP184 a few days ago and it seemed to work just fine (original firmware version was probably the predecessor "2020 something").
After the firmware update (see above) the KP184 was functioning "OK" for several hours, but now, in the midst of a continous 6VDC / 1A load measurement the voltage display (plus the corresponding wattage display) stopped working, just showing now "all zeros", no matter what signal it was currently fed.
I haven't had any success in finding the cause even after intense searching, although I tried a different (proven) lab power supply from BK Precision I got in my "lab" instead of the Rigol DP832A, different input voltages and amperage profiles, switching voltage sensing from "remote" to "local", a reset to factory default parameters, disconnecting it from the mains, turning it off and on again etc. etc. etc...
Measurement gear connected directly to the output of the power supply are prove of a functional power supply by either unit. Voltages etc. are continously monitored by two Rigol Lab DMMs (6 1/2 and 5 1/2 digits resolution) Everything I could think of to remedy the problem I already tried. I inspected all the PCBs inside the unit without any success and found no hint about any visible cause for the failure. Main board version is "5 (202012)" including the daughter board, display board version is "3". The included test certificate is dated October 20th 2021. Could be a firmware "thing", because your firmware update notes for the new firmware seem to point suspiciously into that direction (=>voltage handling) ?
I don't know, what is going to happen, if I am trying to
reinstall the firmware -again- , which is on the KP184 already. Reason: I don't want to be left with a non-functional unit in an incomplete firmware update state, if it's not possible to reinstall the firmware version over the existing one, because i might return the disfunct device. This seems to be my last resort before returning it to the seller...
Otherwise if this is not possible, I would try to reinstall the
previous firmware version. Do You have it also ?
If nothing helps, I will contact the seller, being on the verge of returning the KP184, if the problem can't be resolved on my side...
Ps.: Is that new firmware an official release of the manufacturer (Kunkin) or is it "homebrew" ?
If it is "offical" could you check, if an update for that firmware is avilable, may be a "bug fix" ??