Hello!
I want to use a solar powered cell-phone power bank to continuously power my Arduino Mega (and its accessories) for a VERY long time. This is because I did not want to spend the time or money to create my own solar charge circuit.
So, I am wondering what kind of power bank would be good for the Arduino Mega.
stupid-questions:
This one seems to have too many amps. Would it fry the Arduino?
That's not how power supplies work. What you are asking about is the maximum rated current. This value is supposed to be larger than the total current draw of everything it is powering (the load).
Maximum rated current is the amount of current it can source before frying itself; this is not necessarily the current it outputs. The load (i.e. Arduino and sensors) determine how much current is drawn from the power supply.
The linked power supply looks good to me, EXCEPT that the output voltage looks to be 5V, which is too low to power the Arduino off the Vin pin. If you're brave enough, you can connect the power supply to the 5V pin to power the Arduino instead.
Power_Broker:
The linked power supply looks good to me. Shouldn't be a problem.
Cool! Thanks!
One more question: I have found on the internet that powe banks turn themselves off if they do not detect enough output. Sometimes that's a problem for Arduino.
Sorry, but I changed my reply. It's still possible to use, just risky.
stupid-questions:
One more question: I have found on the internet that powe banks turn themselves off if they do not detect enough output. Sometimes that's a problem for Arduino.
Will that be a problem in this case?
Not sure, but if it is, you can put a correctly sized and rated power resistor in parallel to the power supply. That would fix it.
Standard Arduinos are extremely wasteful of power. Circumventing the low power drain shutoff on the phone charger battery with a resistor will waste a lot of power and defeat your purpose of running an Arduino for a long time.
A "bare bones" Arduino will run for years from 2xAA batteries, if you follow this low power tutorial. Or, see how to make a solar powered Arduino that uses a supercap instead of a battery.
stupid-questions:
Hello!
I want to use a solar powered cell-phone power bank to continuously power my Arduino Mega (and its accessories) for a VERY long time.
Any suggestions?
Yes forget about the capacity of the power bank, its just not relevaent for 'very' long term solar powered use.
Its the charge current capability of the solar panel you need to know.
And when you measured the "Arduino Mega (and its accessories)", how much current were the using ?
jremington:
Circumventing the low power drain shutoff on the phone charger battery with a resistor will waste a lot of power and defeat your purpose of running an Arduino for a long time.
Exactly. As I said:
Power_Broker: correctly sized and rated power resistor
I'm not saying that the resistor should be super small and pull 50A, but correctly sized if and only if it is even required (doubt that it would be anyway).