Invalid time in real time clock

Wayne Sierke ws at
Thu Feb 6 15:25:19 UTC 2014

On Sun, 2014-02-02 at 15:23 +0000, Christian Weisgerber wrote:
> Christian Weisgerber <naddy at> wrote:
> > > atrtc0: WARNING: Battery failure indication
> > > Invalid time in real time clock.
> > > Check and reset the date immediately!
> > > 
> > > Incongruously, the RTC time is actually correct.  Well, off by a
> > > minute or so.  Clearly the new battery is good.
> > 
> > Turns out I misunderstood this.  I thought the system time was still
> > set from the RTC despite the warning.  It isn't.
> Still, booting into the BIOS shows that the RTC keeps up, so it
> shouldn't be a battery problem.  I cleared the RTC memory, set the
> date and time in the BIOS again, but I still get the warning and
> FreeBSD ignores the RTC.  It looks like the RTCSD_PWR bit is stuck
> and there is no way to reset it.

Hi Christian,

When you say "the RTC keeps up" do you mean that the RTC keeps time when
mains power is removed - i.e. power cord unplugged for a "reasonable"
length of time? If the RTC doesn't "survive" complete removal of power
then you may want to double-check the CMOS jumper and battery.


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