Aiming for a year of battery life
Posted:
Tue Feb 28, 2017 6:59 pmby nr32
Hi! I'm looking for a cost-effective battery that can power an ESP8266 in deep sleep. All the ESP8266 is doing is reading an ADC value and sending it over WiFi, waking up once every hour or two. It would be fantastic if a year of battery life could be attained for < $1 in power supply component costs. I found a 300 mAH 3v LiMnO2 battery for $0.25 each, but no idea how long it'd last for such an application. Thanks for your advice.
Re: Aiming for a year of battery life
Posted:
Wed Mar 01, 2017 7:22 amby schufti
hmmm,
let's asume active time (wakeup, measure, connect wifi, transmit data) is about 3s @ ~150mA avg.
so deepsleep is about 7197s @ ~50µA avg. totals to ((3*150+7197*0.05)/7200) ~0.1125mA/h * 8760h/a --> needed capacity 985 mA/h (not provided for self discharge, leakage currents, temp. degradation etc).
beware that the voltage might drop below minimum for esp/eeprom/sensor earlier than the end of capacity is reached.