Sacman,
Thanks for the response. I think my mistake was that I should use the LD1117V33 switching voltage regulator, which is a 3.3v regulator, rather than the LM7805 that I mentioned in my last post. And, I wasn't specific that this would go with the 8MHz Arduino Pro Min, which only requires 3.35v input. Coupled with mauried's suggestion, I could use five D-size NiMH batteries at 6v and drop the voltage to 3.3v using this regulator to power the 8MHz Arduino pro Mini?
mauried,
I like the idea of NiMH instead of Li-Ion. If my suggestion to Sacman holds water, I would be using five D-size NiMH and this solar panel. That means the battery would produce 6v with 10000 mAh capacity while the solar panels would produce 6v and 330 mA? Would that work and is it sufficient to wire them up directly, in a parallel configuration, to trickle charge?