In this first chapter i will discuss some of my tests and experiences using a microcontroller ESP8266 connected with a SIM800 with the objetive of send data to our servers.
But, using LI-ION batteries connected to a low power solar-panel as power-supply.
Making the PCB
The first step was to create a circuit which contains the ESP8266, and a slot for SIM800L module.
I made this board using the easyEDA software, which is pretty simple to use.
The final boards:
The first problem: False LI-ION Cells
The first problem i had has been to buy a generic li-ion battery, the "firepro" ones, with a theoretical capacity of 1500mAh. But its actual capacity was about 15-20% (225-300mAh approx).
The solution for this was to buy samsung batteries and, of course, test each one to make sure they work with the capacity that i spected. ( before use a battery, is important to check the real capacity of each battery because some times they re some kind of weird clone from china )