I have a wireless proximity sensor that I had planned on using a 5V lithium battery (sold as a spare battery that can recharge your phone if it dies); however, it seems that the battery has some internal circuitry that can detect a load and switch off the output if there is none. Easy fix: just make sure there's a load provided and the output will stay on, right? Right! Well, sort of. It stays on and powers my circuit for about 30-60 seconds and then shuts off. My circuit is well within the 1000mA current limit listed on the battery. I tried adding a dummy resistor to it thinking maybe my circuit didn't draw enough current, but that didn't help. I have two of these batteries and am getting the same results from both. Any ideas?
kengel:
I tried adding a dummy resistor to it thinking maybe my circuit didn't draw enough current, but that didn't help.
Correct, but the resistor must be sized to the Arduino/powerbank, and pulsed to not drain too much.
Has been done many times before.
Google "Arduino powerbank".
Leo..