@Heizelmann said:
E = 1200 mAh ___________________avarage battery capacity of Alkaline AA
Your 3 minutes sleep rithm using 4 mA per hour results in 300 hours =~ 12.5 days.
Educated guess: With a 10 minutes sleep rithm using 6/20 * 4 =~ 1.2 mA, it would last ~ 41-42 days.
Edit: You feed via usb meaning 5V also meaning via the power regulator. You didn’t mention whether you were sending and displaying on the LED or so.
Also: Did you remove the status led? I did.
Let’s see. I’m on day 5 now.