I have some ideas for Arduino Nano projects I'm throwing around that I would like to power only with a solar panel and I'm wondering if I am going about it the right way. I have: A 7.2V 100mA solar panel, a couple of AAA rechargeable batteries, my NANO(s), and external components. This seems like a complicated project to a noob, so I'll try to list just a few concerns.
- Is the 7.2V solar panel compatible with five 1.5V rechargeable batteries?(7.5V when put together in series). I'll just connect + to + and - to - and it will slowly charge?
- Should I be concerned about my power supply slowly dropping voltage every night for weeks or months (hopefully years) and charging in the morning, and messing with the circuitry of the nano? I would assume that at night it would die off after a couple of hours, but that may depend on how much power my external components are dissipating.
- This may have to be found out experimentally, but does the solar panel produce enough power to at least keep the Nano on and charge the batteries?
I'm thinking it should be a simple circuit, solar panel→batteries→Vin & GND (5V regulator is built in, of course). But if the low voltage while charging and dying off is a problem, I was thinking about using a low-voltage indicator circuit to tell when the power drops below 6.5-6.9V:
YouTube video: https://www.youtube.com/watch?v=Z0cOO0TNjNA
and some logic gates, maybe a NOT gate and replacing the positive side of the LED from the circuit above with the input for the NOT gate, with the output going to Vin. Hopefully a transistor NOT gate can withstand the 7.2V.
Please tell me what I should change and anything I should be aware of. Thanks in advance.