I have searched the forum for some answers but nothing seems to fit my question.
I'm planning to use an simple external battery (2600 mAh) which outputs 5V 1A and has its own charging modules. Im using the USB port from the D1 Minis board. I don`t know the technology in the battery.
Is there a way to find out when the voltage drops without cracking open the case of the battery? and if there is, how should i calculate in code the value and what resistors should i use?
I`m searching for any indication that the Wemos D1 Mini is going down soon.
A powerbank like that ought to manage its battery itself - when the battery is flat, it will cut off. I presume
you want some warning of this?
The typical powerbank pcbs have 4 or 5 status LEDs on them to indicate SoC (state of charge). Perhaps
connecting to the lowest power indicator LED would be one way to piggyback the SoC information?
In this case the battery has a single led which turns blue or red, which might be an idea anyway. But, the battery cuts the power when the voltage drops to low, maybe that reflects in the output. Between the board`s usb and the battery output, may i feel some changes? And if yes, how, or where, on the 5V pin ?