I need some help regarding powering the Arduino with a portable cell phone charger. I once saw a video of someone using one and I bought a charger to try it out. Even though the charger specs said 5v output, I came to find out it is only the boost output voltage which last for a few seconds before stepping own to 3.5v or so. I thought maybe I read the specs wrong and later ordered a different one that talked up it's 5v output but it too does the same thing (why don't they just say 5v boost, 3.5v continuous?) . I ended up giving it to my wife for her phone. I can't find the video I first saw someone using the portable charger.
Is there such a thing? I am interested due to the much larger mah capacity of portable chargers and its relatively small footprint which would allow me to run the Arduino for a very long time in a compact form. I run the atmega328 in low power mode (average ~7ma with accesories) which seems to work well...just looking for a larger capacity 5v battery source.
Thanks for any help.