the system will contain number of slave devices (nodemcu esp8266) that i have to run for almost 8-10hrs (only 1 on each battery) i know that they require 3.3 volts at 80mA current to work

Im trying to find a formula to calculate the charging/discharging time of the capacitor to compare it with normal batteries i have ultra capacitors rated at 500f 2.7v that im going to use for the same

I found this post and wanted to know if it could be used to calculate the charging/discharging time of the capacitor

http://fiziknota.blogspot.in/2010/01/relationship-between-energy-voltage.html

The basic block diagram is attached if it helps