SunFounder Pironman - Page 50

SunFounder Pironman
Enable Trickle Charging
• The Raspberry Pi 5 supports charging the RTC battery. By default, the trickle charging feature for the battery is
disabled. The sysfs files indicate the current trickle charging voltage and limits:
Warning:
– A rechargeable ML1220 battery can be used here.
– If you are using the CR1220 non-rechargeable battery provided in the kit, make sure not to enable
the Trickle Charging feature.
pi@raspberrypi:~ $ cat /sys/devices/platform/soc/soc:rpi_rtc/rtc/rtc0/charging_
˓→voltage
0
pi@raspberrypi:~ $ cat /sys/devices/platform/soc/soc:rpi_rtc/rtc/rtc0/charging_
˓→voltage_max
4400000
pi@raspberrypi:~ $ cat /sys/devices/platform/soc/soc:rpi_rtc/rtc/rtc0/charging_
˓→voltage_min
1300000
• To enable trickle charging, add rtc_bbat_vchg to /boot/firmware/config.txt.
– Open the /boot/firmware/config.txt.
46 Chapter 6. 6. About Hardware