I did wonder.Another option is to but a portable battery charging unit.I have one somewhere which i was going to use when I was going on holiday.It was also going to be used to charge my dslite on the plane.Not sure how good it would be though.Perhaps carrying spare batteries?
Also how muchwould you use it?
Can always turn it off at night to save battery,that's if you don't already do so.
I did wonder why the E52 though.