If I haven't used the K2 for a few days, it sometimes falls back to the default settings.
It doesn't matter which version of the app I am using.
The battery voltage of the motorcycle is not a problem, it is always good. I also have the latest version of the power supply, with blue LED. Re-flashing the software does not affect the problem either.
But could it be that the backup battery (if any) in the K2 is starting to go bad?
The serial number of the K2 starts with INNOK21806xxxxx. Is it true that the K2 was produced in 2018? It could indeed be that the backup battery is starting to go bad. When I look at the picture of the pcb board, replacing the backup battery shouldn't be a problem.
At least if the backup battery is what I can find on the pcb board, see also the attached photo.
Is this backup battery available separately? If so, how can I get this backup battery? I have experience with smd soldering and can therefore replace it myself.

Thanks Frostie for the quick response.
Hi Hans,
This should be the correct battery.
https://www.amazon.de/Seiko-MS621FE-FL11E-Super-Kapazität/dp/B07LG5FVXB
Unfortunately, the problem has definitely returned.
So the cause was not the tyrap who might hit the reset button.
The K2 has already reverted to the default settings several times.
The problem now occurs when the motorcycle has not been used for 4 to 5 days. Perhaps it also has to do with the temperature in the garage starting to get colder. Temperature is around 6 degrees Celsius.
The battery voltage of the motorcycle is always above 12.3 volts. When the motorcycle is not in use I always connect an Optimate 4 battery charger.
So I am starting to doubt the quality of the backup battery.
@innovv Is this backup battery available separately?
I have experience with smd soldering and can therefore replace it myself.
Meanwhile, the K2 had several days off the power supply. Settings as I have set them are still there.
The problem could also have been that one of the tyraps with which I fixed the K2 has pressed the reset button. I have moved this tyrap and had no problem until now.
@INNOVV MotoCam I am now testing when the settings go back to factory defaults.
Testing will take a while.
I want to test per ascending day, 1 day without power supply, 2 days without power supply, 3 days ... and so on.
@Frostie Thanks for thinking along.
I will work with the tips. Hopefully I can get closer to the root of the problem. Have just disconnected the power supply from the K2.
Check in a day or so whether the K2 has saved the settings. To be continued.
According to one Innovv posting, the battery is only for the RTC. Even when removing the battery, the settings will stay.
https://www.innovv.com/forum/innovv-k2/app-reset-itself-overnight
But according to another posting from Rock, the behaviour you mentioned can be due to a faulty battery.
https://www.innovv.com/forum/innovv-k2/dose-not-keep-the-settings
So...well...I don't know for what the battery is exactly for. But getting a replacement battery should not be a problem at a local store. It looks like a standard battery.