RTC Battery

The Rhino Pi IQ9N (Rhino Pi IQ9N) supports a clock backup battery (RTC), which maintains the system time after the device is powered off.

Hardware Specifications

For the position of the RTC battery connector on the board, see the interface layout diagram in Rhino Pi IQ9N Interface Description on the first page.

Item	Parameter
RTC support	Supported
Battery connector	RTC-BAT
Watchdog function	Independent watchdog supported
Watchdog timers	The MCU provides 2 watchdog timers (independent and window type)

Function Description

• After the main power is disconnected, the RTC is powered by the backup battery and the system time keeps counting.
• After the main power is restored, the system reads the time from the RTC without needing to re-synchronize.
• The onboard MCU is based on a Qingke RISC-V2A core, supporting a 48 MHz system main frequency, with wide voltage range, single-wire debug, low power consumption, and an ultra-small package.

Viewing and Setting the Time

View the current system time:

date

View the system time, hardware clock (RTC) time, and NTP synchronization status:

timedatectl

The RTC time in the output is the RTC hardware clock time. You can also read the RTC device nodes directly:

cat /sys/class/rtc/rtc0/date
cat /sys/class/rtc/rtc0/time

The device has NTP automatic time synchronization enabled by default; the system time is calibrated automatically and synchronized to the hardware clock, so manual adjustment is not needed in daily use.

To set the time manually, first disable NTP automatic synchronization, then re-enable it after setting:

sudo timedatectl set-ntp false
sudo timedatectl set-time "2026-09-30 11:30:00"
sudo timedatectl set-ntp true

Note

When NTP automatic synchronization is enabled, timedatectl set-time returns Failed to set time: Automatic time synchronization is enabled; in that case run sudo timedatectl set-ntp false first.

Notes

• If the device will not be used for a long time, remove the RTC battery to prevent battery leakage from damaging the circuit board.
• When replacing the battery, pay attention to the battery polarity and perform the operation with the power disconnected.