Why does Turris MOX have RTC battery?

MOX hardware MOX HW help
1

The Turris MOX does not keep time when mains power is removed despite having an RTC battery. The time is always reset to 2001-01-01. What is the purpose of the battery then?

Edit 5 years later:
Turns out my Turris MOX has no RTC battery inside it, which explains the behavior Turris MOX, no RTC battery?

2

That’s re-iteration of this thread, right? DNSSEC not working due to NTP not working and vice versa

I believe RTC is exactly the purpose of the battery and thus something is wrong in your particular case, but I’m personally not confident about these HW details.