Comment 23 for bug 427289

I have checked on my BBG3.0, that the time is correctly kept after a shutdown.
My KCONFIG has this:

#
# on-CPU RTC drivers
#
# CONFIG_RTC_MXC is not set
# CONFIG_RTC_DRV_MXC_V2 is not set
# CONFIG_RTC_DRV_IMXDI is not set
CONFIG_RTC_MC13892=y
# CONFIG_DMADEVICES is not set
CONFIG_REGULATOR=y
# CONFIG_REGULATOR_DEBUG is not set
# CONFIG_REGULATOR_FIXED_VOLTAGE is not set
# CONFIG_REGULATOR_VIRTUAL_CONSUMER is not set
# CONFIG_REGULATOR_BQ24022 is not set
CONFIG_REGULATOR_MC13892=y
CONFIG_UIO=y
# CONFIG_UIO_PDRV is not set
CONFIG_UIO_PDRV_GENIRQ=m
# CONFIG_UIO_SMX is not set
# CONFIG_UIO_SERCOS3 is not set

Please check that:
CONFIG_MXC_MC13892_RTC=y

Also, on my BBG3.0 board, I am measuring 2.69V on the coin-cell. Can you measure on your board what is the coin-cell voltage?