back up battery can not work?

An optional back up battery can be attached to the VDD_RTC module input (this will maintain the on system RTC, when VDD_IN is not present).
But when I test TX1 with back up battery, I found that when I cut off the power for TX1 and repower again, the date of TX1 will be reseted into another time, instead of keep time going using back up battery. And I am sure that my battery is 3.1V and connected to A50(VDD_RTC) of TX1.
Is there any advice?

I test it again, and I found that if I using the reset button in carrier to restart TX1, and every time it start, the time alway start from 9:55, if everyone can help me to solve this problem!!

Hi Chad_Ding,

We don’t see this issue on our side.
Could you provide boot log first? and which image version are you using?