NRF52832 with CMOS battery

[believer]

I am facing an issue about using CMOS battery for NRF52832. I hope this CMOS battery can serve mcu (in low power mode) for at least 1 year. In low power mode, I just want to run an RTC. Can this be possible?

[Ameer Usman]

In accordance to the operating voltage of 1.8V to 3.6V your CMOS Battery is well in that zone and it should be able to pull out a year. But the question is which battery are you intending to use? CR2032? That has a capacity of 225mAh.

[believer]

Yes, I am intending to use CR2032. How can I power NRF52832 by battery? Just connect it to VDD?

[Ameer Usman]

VDD and GND, you can directly connect nRF52832 to the CR2032 Cell (which is rated at 3V). Keep LED link as a debugging feature to know it turned on initially.

[believer]

How can I keep RTC running when external power is disconnected?

I think I could detect VDD under 3.3V and disable all other module but RTC.