I agree. A quick Google search suggests that the human body requires about 100 Watts[1] of power. On the other hand, a small 12 volt car battery is able to provide 45 Amps over an hour, which implies that it can support a power draw of 540 watts for an hour. Even if human activity required 200 Watts, an android with human level power efficiency should be able to operate for over 2 hours with the technology of today's small car batteries. Of course, my math could be wrong :-)

[EDIT] - My point here is that even if improvements to battery technology remain slow or constant, with sufficient innovation in energy efficiency and algorithms, we could still have robots with usable to good running times. Just figuring out a reliable walking gait and building materials for passive dynamic walking can significantly reduce the power requirements.[3]

[1] - http://hypertextbook.com/facts/2001/JacquelineLing.shtml [2] - http://www.chem.hawaii.edu/uham/bat.html [3] - https://en.wikipedia.org/wiki/Passive_dynamics

Not everything. The energy required by physics for lifting boxes or driving a car up a hill is pretty much fixed. Better batteries would help with both of those.

I don't think the robots who can do those things are near the physical limits, though.

Electric jets as well.

The energy to raise a fixed mass a certain height isn't going to change.

Not to mention an electric car with a thousand mile range would be huge.

It would certainly put a whole new perspective on range anxiety.

Also, teach the robot to replace it's own battery or fuel.

Yikes! As long as it has some parameters about human safety being more important than batteries or fuel, then by all means...