re: Compressed Air?
I wonder if the technology is available to make a small turbine compressor to slowly collect Martian air into a little pressure bottle for cleaning off the cells. You could only squirt off the cells every few weeks, but you'd never run out of gas. I have no idea what the weight and power penalty would be. I do know that sometimes the rovers have to "rest" after doing something that takes a lot of juice, like using the grinder or moving around.