Is there such a thing as a battery-powered water-filtration system on the market? If you have ever spent long ounts of time and huge ounts of energy pumping water out of a lake or stre, you can see how carrying some small batteries to run such a system would be advantageous. Right now I use an MSR hand pump, which I just find is too labor-intensive. Carl Ellerslie, Georgia
So, the short answer is this: No, there aren't any battery-powered water-filtration systems out there.
As for a longer answer: Carl, there's a reason it takes some effort to filter water. The pump action pushes water through an extremely fine filter, fine enough to catch tiny little creatures you can't possibly see with the naked eye. So of course it requires some effort. For my part, I worry when a filter DOESN'T require much pushing, as I then figure it's really not doing much filtering. I'm not sure what MSR filter you have, but I often use an MSR MiniWorks ($80; www.msrcorp.com) and find its pump handle gives me quite a bit of leverage, and at a comfortable angle.
Meanwhile, you could try this: MSR's fairly new MIOX Purifier ($130). It's the size of a fat pen, and uses camera batteries and salt to create a powerful bug-killing compound that is added to untreated water, eliminating viruses, bacteria, Giardia, and Cryptosporidium. No pumping needed!
Read more reviews of the best water-filtration systems in Outside's 2004 Buyer's Guide.