ESP8266 Community Forum

- Mon Dec 18, 2017 10:04 pm #72566 Like to pick a grey cell'er two... I'm doing a "Smail's here" setup. I've got the code working: boot, connect, send a text, deepsleep(forever). It runs for 15 seconds once per day. I'm having problems putting together a power source and just came up with an idea
https://electronics.stackexchange.com/questions/304133/need-a-soft-latching-power-on-off-that-starts-off
A latching PS. I've found a design: pushbutton fires a NE555 -> 2N3409 which suppliesV+ to my 2866. The RC side of the 555 times out after a (?) minute (30sec), shuts down, turns the 2N3409 off and the power to my 8266. In the off condition the power draw should be ?? zip ??

But I thought I'd ask around before I ordered 200 transistors (amazon, 20 for 4.95 or 200 for 6.25) (and in some cases 20 for 6 and 200 for 4 ???). Thoughts???

- Tue Dec 19, 2017 4:31 am #72577 look here

- Tue Dec 19, 2017 6:59 am #72580 Also bear in mind the self discharge of the battery. Although low for Lipo it can range from 2%-5% per month. The current consumption of having the module powered all the time with EN low then becomes an extra small contribution. So you have to factor that in to see if it is worth going to the trouble of a fancier power switch.

- Tue Dec 19, 2017 3:21 pm #72587 one can also use these huge capacity D-size Lithium primary cells (LiSOCl2).
With 14.2Ah @ 3.6V (max of ESP8266) nominal they last you ages (longer than guaranteed storage period) on 60µA (~worst case current draw of ESP-01 in deep sleep)

do not overlook pull ups/downs in the energy balance!