[Paddlewise] Powering Electric Pumps

On the subject of electric pumps, "West Marine" stocks a variety of "Rule"
brand electric pumps with various GPH rates. Some have automatic switches
and some have a manual switches (and being good retailers, they of course,
sell various waterproof switches...). Most of these pumps are the size of a
small can of tomato paste and are priced $60 and under. 
My question is what are the methods of powering these pumps and approp.
sealing of the batteries. It would seem that some type of rechargeable,
sealed gel battery (i.e., small "Quantum" batteries used by photographers)
might be a good choice if it can be properly sealed and protected.
Otherwise, I can see a substantial weight penalty if you start getting into
the larger lantern batteries.
Other ideas?
***************************************************************************
PaddleWise Paddling Mailing List
Submissions:     paddlewise_at_lists.intelenet.net
Subscriptions:   paddlewise-request_at_lists.intelenet.net
Website:         http://www.gasp-seakayak.net/paddlewise/
***************************************************************************