Alternative power/recharging source?

[Ben Goetter]

 >> hours...using gravity! :-) (Consider the XO using
 >> about 2 watts...)

There seems little danger of this mechanism being useful on Earth for 
the XO-1.  A 30kg human child who can move her own mass a meter 
vertically (via a series of pulleys, or perhaps just climbing stairs 
with a buddy riding piggyback etc.) can invoke only 300J of potential 
gravitational energy, or enough to let an XO sleep for two and a half 
minutes assuming a 100% efficient conversion from gravitational to 
electrical potential.

Now on Jupiter (G = 26, nonhuman "children" massing 270kg, each able to 
relocate their own mass 3m vertically due to longer motor tendrils) they 
could invoke 21060J, a theoretical maximum of 5h50m of sleep time.  Now 
we're talking.

Apologetically,
Ben