ESP8266 Community Forum

- Sat Aug 06, 2016 12:51 pm #52298 It seems like Your web update server refuses the connection from ESP. Anyway I suggest to raise voltage at least to 3V...

- Sat Aug 06, 2016 1:01 pm #52300

It seems like Your web update server refuses the connection from ESP. Anyway I suggest to raise voltage at least to 3V...

Yes I had worked that simple deduction out myself Having no issue with anything other than the ESP update it is something related to the update library, I have opened a bug topic here:

viewtopic.php?f=28&t=11167

With two brand new AA batteries and the 3.3v input from the programmer it is giving me the voltage as described above, currently 2.94 with the 3.3v off the programmer. I have also found out the ESP can operate between 1.7 and 3.6v. I have some step up regulators on their way will have to wait for those I guess, there are too many road blocks with ESP, it operated at 3.75 via AA for 7 hours and now will not operate using two new batteries yet operates using the 3.3v input which is giving 2.94. Getting tired of all the issues with this chip and inconsistencies, have started looking for alternatives.

Amazing selection of ESP8266 and ESP32 modules can be found here.

- Sat Aug 06, 2016 1:06 pm #52304

Hi,
yes cells like the one you found on ebay (maybe you find cheaper supply in rc-model or e-cigaret shops, indication usually is 3.2V). For this type charging is dead simple. 3.33-3.45V gives you full charge if limited to 4C and done until current drops to 0 (or 1C with 3.6V) and almost no risk of overcharging (they even manage 4.2V w/o exploding). With common smartphone USB charger you probably won't get more than 1.5A, even less on cheap solar cell; so not too much concern.
Stated 2V lowest discharge is not recommended. With 3.0V (safe for esp) you allready have more than 93% discharge. The recommended cc (read: limited current)/cv charge is easily done with simple linear regulators. Either fixed 3.3V or variable (LM317/117) with just using internal current limit or external limiting circuitry (see datasheets) according to a.m. cases. Allthough this is not the recommended nor the most sophisticated charging (but easy and cheap to implement), LiFePO4 have much more (3-4x) cycles than standard LiIon but slightly lower capacity and are much safer to operate!

Being able to save power and receive data should be possible, but seems to be tricky. See: viewtopic.php?f=29&t=11132
But power reduction is far from deep sleep or power down.

So that battery is good to get ? I am finding it hard to find any tutorials or docs on setting up a circuit with this type of battery, do you know of any good tuts ?

Amazing selection of ESP8266 and ESP32 modules can be found here.

- Sat Aug 06, 2016 1:31 pm #52309

With two brand new AA batteries and the 3.3v input from the programmer it is giving me the voltage as described above, currently 2.94 with the 3.3v off the programmer. I have also found out the ESP can operate between 1.7 and 3.6v. I have some step up regulators on their way will have to wait for those I guess, there are too many road blocks with ESP, it operated at 3.75 via AA for 7 hours and now will not operate using two new batteries yet operates using the 3.3v input which is giving 2.94. Getting tired of all the issues with this chip and inconsistencies, have started looking for alternatives.

So You've trying to operate ESP outside limits, specified in datasheet, and blame that chip for errors (no offense please) Alternatives I've found so far are: NL6621, RTL8710 - I wish You good luck, because I've failed There is no community like this so far so You are by Your own...