RTC super capacitor backup

[charlespax]

Maybe use a super capacitor.

Things to consider

• super caps are probably more expensive components
• The coin cell battery is lithium, which comes with various shipping challenges
• Would a super cap solution have a smaller footprint?

[charlespax]

Here is a super capacitor calculator: https://www.maximintegrated.com/en/design/tools/calculators/product-design/supercap.cfm

Seeed has a module, but I can't find the schematic. http://www.seeedstudio.com/depot/RTC-Module-Super-Capacitor-p-2137.html

Topic on Stack Exchange. http://electronics.stackexchange.com/questions/26855/supercap-powered-rtc

What is the minimum voltage for the STM32 battery backup? 1.8 V to 2.6 V

[charlespax]

I'm going to ice box this. Maybe come back to it later.