Originally Posted by
boomhauer
The biggest hurdle I can't get over is charging a battery just so you can charge another battery later (your phone, etc....)
You probably lose 30% of the energy just doing that!
You've just wasted 30% of the time you took to charge your cache battery in the first place.
I've got a dynamo hub that goes thru a Sinewave converter to charge my Iphone 6+. No intermediate battery required to run my phone all day (listening to Pandora Radio).
Some devices are much more picky about their power supply than others, that is one reason that some people need to charge a battery and then use that to charge their device later.
My Sinewave will not charge the batteries in my Garmin 64 GPS, but if I use a cache (pass through) battery it will charge.