I want to create a pcb for a product soon and doing some tests I found that rtc and eeprom values are lost when I unplug power ( I think I read some time ago but I didn’t remember it).
I was considering an i2c eeprom and a rechargeable coin battery for rtc in case the users were not using wifi.
But I read that rtc and eeprom storage consume just 4uA. When the power is on, battery is not discharged, is it?
So, a 80mA battery could last for more than 3-4 years in good conditions. I think this is more than ok for me, the user could remove the case and change the coin cell if needed in some years.
Is this correct? Battery connected to Vbat is not used when power Vin is in use?