Hello. I am building an Arduino robot controlled by an Arduino Mega. I wish to make it solar powered.
I plan to use a solar panel like this one:
The solar panel will charge a 9V battery such as this:
The 9V battery will be plugged in to the Arduino Mega, and power it. When the Arduino Mega detects the battery is almost empty, it stops what it is doing and allows the solar panel to recharge the battery.
Will these parts I linked to work in a system like this? How would the Arduino Mega detect if the power is low?
That solar panel is rated for 1.25 Watts in full sun. The battery holds 9V * 0.2Ah = 1.8 Wh so it would take over an hour to charge your battery in full sun with no losses in the charger circuitry. Figure about 100mA for the Arduino alone and each charge will last about two hours.
If you add a motor or two so your robot can move... figure another Amp or two for those and you will get about 6 minutes of motion for each two hours of charging.
I think you will need to consider your power requirements in more detail before you pick battery and charger components.
Maybe two of them wired in series would do the trick…
-SQ
That voltage rating is open circuit, full Florida sunlight. Any load, like a charge controller will quickly reduce that voltage. Yes, two on series and a charge controller will cut the charge time that Johnwasser gave you in half. Still won’t run motors.
stupid-questions:
Hello. I am building an Arduino robot controlled by an Arduino Mega. I wish to make it solar powered.
I agree with @jremington. Your question demonstrates the fact that you need to do a lot of study before you will be ready to specify the parts for your system.
My approach to that sort of project would be to choose a battery that can power the robot for a specified amount of time - maybe an hour would be sufficient. That would require figuring out how much energy the total robot system will consume and choosing a battery with about twice that capacity.
Then I would figure out the time over which I wanted the solar panels to replace that energy. Assume that in normal use a solar panel will produce only 25% or maybe only 10% of the sticker output.
After all that you still have to make sure the battery voltage is suitable for the Arduino and the robot motors and that the solar panel voltage is suitable for charging the battery.
Sorry but there is no substitute for numbers ... numbers ... numbers ...