ESP8266 Community Forum

- Sat Jun 11, 2016 7:58 pm #49033 Can you please explain me what this guy here talking about ?

For newest versions of the SparkFun thing, you can simply unsolder the “PWR” jumper at the back of the board. For older versions like the one I have, you can simply cut the trace between the PWR LED and the nearby resistor. After that, just power the project again. The reading on the multimeter immediately changed to 77 uA, or 0.077 mA. This means that the same project will now last on the same battery for … 3.7 years! Of course, this doesn’t take into account the characteristics of the battery, so in reality you will end up with 1-2 years battery life for your project.

https://www.openhomeautomation.net/esp8266-battery/

I understand that sparkfun is some board that uses esp8266 for more comfortable use , but how this guys comes up with years ?

- Sun Jun 12, 2016 3:47 am #49051 Hi, from this schematic it looks like the Sparkfun thing has an LED (D4 & R16) to indicate 3.3V is present. Given red LEDs have about 2V forward voltdrop this will draw:
V= I*R or I = V / R
I = (Supply Voltage - LED forward volt drop) / Resistance (R16).
I = 3.3V - 2.0V / 200 ohms = 6.5mA.
So basicaly he is saying that even in deep sleep, this board LED will draw 6.5mA or 6500uA even though the ESP only draws 77uA and will be mainly responsable for the battery discharge. So yes disconecting any power indicating LEDs is a must if your going to use deep sleep, and if like he does you disconnect this and use a 2500mA LiPo:
2500mAH / 0.07mAH = 32,000 hours = 1,352 Days = 3.7 years.
Yes in deep sleep an ESP can run for a long time on batteries, the fun bit is when you wake it up to do something and it draws lots of power.

- Wed Aug 17, 2016 9:56 am #53152 Hi,all
Hope my analysis will help those who are designing with batteries and to help choose the apt power supply.
Please see the attached waveforms for a better insight.
Peak current at startup: approx 320mA @3.3V, so your power supply must be able to handle this. I use a large cap (470uF SMD) as the peak only comes up periodically.

i'm newbie to this forum,

i'm using the chip ESP8266EX QFN32 package. not module. developing my own module. so the above mentioned startup peak current is true for chip also. isn't it???

i'm also want to know the startup time and time taken to sht down and peak current in these times. i think you can help me. please reply as early as possible.

Thanks in advance

- Thu Aug 18, 2016 10:15 pm #53265 Thanks for all the great info on power consumption of the ESP8266. I'm building a bunny detector for the kale garden. I'm a noob at ESP2866 and battery powered devices so forgive me if this is a silly question, but is there a way the PIR could pull the ESP8266 out of deep sleep mode? So the module just sleeps until the PIR signal line goes high. Thanks Again!!!