I just recently bought this Arduino and have successfully created a small app that transfers data over my private WiFI network.
The app works fine when power is supplied via a computer USB port. Since I need to eventually locate the project away from a power connection I connected an ATIVA 10000mAh power pack (typically used for iPad & iPhone). According to specs it supplies 5V at up to 2.4 amps. The Arduino powers up OK and starts running the program normally. However, after some random number of program cycles (5 - 800) the Arduino stops responding and the CHRG LED starts flashing about 1/sec. It appears this particular power pack does not meet the requirements to power the Arduino within its requirements.
Is this typical of these type of power packs? Can anyone recommend a power pack that will work? I need about 12 hours of run time.
I believe the issue is your Arduino does not use enough power and therefore triggers the shutdown on your power pack. The power packs are build to charge smartphones and when they detect a current below a certain level they assume the phone is finished charging and switch off to protect the internal battery from being drained. Most phone users do not know to much about mAh and only count how often they can charge the phone. Trickle charging does not count.
There are circuit boards made for Arduino type of applications with 18650 battery holders on them. They are basically a power pack without a casing around and they work fine. I got a few from Amazon for around 5 bugs a each. Search "18650 shield" in Amazon.
I run some experiments with ESP32, ESP8266 and Arduino Nano 33 IoT boards and they worked up to one or two days with WiFi connection, sending sensor data every minute on a single SAMSUNG INR18650-35E (~3500mAh).