I want to power it with a little solar panel and 3 AA backup batteries.It would help to know how big you expect the flag to be and how much current we’re working with. Voltage just isn’t enough information to know how much work we are doing. If you are talking about the 5V from, say, an Arduino, that’s not going to get you much. Or, from a USB port, well, same there. So, what’s the story with the size and power supply?