网上有人说IMX6UL的内部RTC功耗大,钮扣电池耗完,如果是的话,可以外挂时钟芯片RTC
For your information,this is the datasheet of the i.MX6ul.
http://www.nxp.com/files/32bit/doc/data_sheet/IMX6ULCEC.pdf