or that 5V is important for some reason.
I don't think the exact voltage matters for us, so long as the microcontroller is running stable.
Quoteor that 5V is important for some reason.You are trying to imply that it isn't?
QuoteI don't think the exact voltage matters for us, so long as the microcontroller is running stable.There is a big difference between exact voltage and consistent voltage. Batteries will give you neither.
Given their low cost I'd really REALLY consider using an LDO regulator when running from batteries. I wouldn't feel comfortable feeding any microcontroller-based project from an unregulated supply, even from batteries. It doesn't really add much complexity to the circuit