So this is where the VVPV ( VariVolt PV ) can be discussed.
I have had to re=evaluate the design , the original design used a custom molded case that held 2 14500 batts and a VariVolt controller like the Buzz and a battery charger .
The enclosure/case molds were going to be $5-6k so !! NO GO
I am working on the new design that uses a different MFG type to make the case , It will be lower cost and still look good .
Also I am designing it for a single 18650 battery ! with a Variable voltage controller for the 3.6 to 6 volts control ( just like the Buzz ) and a 6ml Juice bottle with pump action + a Battery charger built into it.
SO the main difference will be the battery and the depth of the case .
BUT It will have A 18650 2400mah battery with Juice Feed and charger , I plan on a better voltage indicator as well for it .
I have one question ?
DO you want a fixed voltage switch ( 6-10 position ) or a Pot like the BUZZ ( Either will have a knob for adjustment )