It looks like I may have a bad RV3028. It was working fine as near as I can tell but is now unreliable after doing a config txt edit
It now craps out if left for any amount of time. I booted up that Pi yesterday and the time was off. And running
sudo hwclock -r gets me that error message.
hwclock: ioctl(RTC_RD_TIME) to .dev/rtc0 to read time failed: invalid argument
I reset it to the correct time, and tested it once. After about a 15 minute shutdown with no power to the Pi it was Ok. But after leaving it unpowered overnight its not working anymore. It showed yesterdays time and hwclock -r gets me that error message above. Bad battery maybe? I powered down and swapped in my other RV3028 and it read the correct time. I didn’t have to do anything. I had checked this second one yesterday and its been sitting unplugged since then. This Pi is not connected to the internet. I’m going to leave the second RV3028 in and power down, then check it in a few hours. If it works its likey a hardware issue with the other one. If it doesn’t its software I guess?