kydra1:
I need the combined voltage to run the boards.
Look into DC-DC Boost Converters. Cheap ones can output maybe 2A but you can buy much more capacity for not greatly more money per amp.
I have cheap ones that can turn 0.9V to 5V. The output jack is a USB jack, same as an MP3/phone charger. A low power project can run on a single AAA for a while. Or, 4 'dead' batteries in series can be drained down to .9V total.....
If you have any long wire runs, use a DC-AC inverter and switching power supplies where you want DC.