Floor robot batteries

It seems my Scooba's batteries have died again, both of them at the same time.  I'm getting not more than ten minutes of run out of either of them.  One of them had been a bit weak, but the other one was going strong.  They're not that old, either.

My Roomba's batteries are also a concern but for a different reason.  All previous Roomba generations used an external battery you could snap in, the same as the current Scooba, and which could be charged outside the Roomba.  This was ideal: while one battery is in use the other one is charging.  That's really the only way to keep a steady pace of Roombaing going.  (The "returns to docking station"/"runs on a schedule" thing they put in is just there to appease those who think it's a good idea; once you have it you learn that it's pointless, since you have to empty the dirt bin anyway.)  But the current generation uses a battery that can only be swapped by removing five screws and a cover plate.  Not too hard, but harder than it needs to be.  More importantly, you can't charge them outside the Roomba.  So if you have two good batteries you can at most do two battery runs before you have to stop and recharge; no chance to keep the running and charging in parallel.  This is a big downgrade and for no reason I can think of.

I still love my Roomba and Scooba, but I've had them a long time and I start to get spoiled, so I only see the bad parts, while the good parts I take for granted.  And all the bad parts have to do with batteries.  The other big problem I have with them is the virtual walls running low and not working, but not telling me this in any useful way, until I find my robots wandering the wrong places.

(Actually, the amount of dog hair that clogs up the Roomba is a bit of an issue these days, but that's going to be the case for any floor-cleaning technology short of nanobots.  Though wouldn't it be great if the Roomba could convert the matter of the dust it picks up to energy, and thus, power itself?  If only we had consumer-grade, floor-portable cold fusion!)

When you come down to it, aren't most of the issues you have with most of the portable gadgets you use, from cell phones and laptops to power tools, problems with batteries?  Any decent sci-fi writer would have had someone invent battery technology two orders of magnitude better than what we have by this point in history, or broadcast power, or something.  To heck with flying cars, what we need is superbatteries.  (Actually, come to think of it, a big leap in battery technology would probably make flying cars feasible.)

Of course, the issue of good batteries is separate from the issue of good energy sources, though naturally related.  If you were going to write sci-fi, you might solve both issues at once by having someone invent an efficient, renewable source of energy that happens to also be able to be made in sizes tiny enough to fit inside robots... and cell phones... and each earpiece of a pair of wireless headphones... and RFID transmitters... and heck, let's go nanotech and let them fit into microscopic machines that can swim your bloodstream, too.  Then you eliminate the need for big power plants, and the distribution infrastructure of wires carrying energy around, and the power companies that run them.  Decentralization of energy generation is at least as game-changing a factor as the cheap source of power itself is.

But realistically if we do get these advances they'll probably be separate: one about cheap, safe power generation, probably still in centralized locations due to economies of scale; and a separate one for a rechargeable, environmentally friendly, energy-dense, light, small mode of including that energy in small devices.  This would have a lot more impact than just making your cell phone easier to use; it'd be like computers themselves, in how the ways it would be used would be far broader than you'd immediately realize when they were new.  The world of medicine alone would have hundreds of applications that would change (and save) countless lives.

Okay, I admit it, I'm stalling.  I don't want to have to buy more Scooba batteries.  Has anyone invented that something-better yet?  I'm ready!