No problems with battery life on our PRS-600! We charge them up when needed. Not sure what planet the OP lives on, as with all portable electrical gadgets they need a periodic charge. The makers claims of battery life, page turns, number of cell phone calls etc etc etc are a simple bench mark in "optimum" conditions. The same analogy could be given for any make of car; the makers claim you get 30 mpg, but then depending on your driving habits, routes etc you might actually only get 25 or you could get 40. In any event you would be stupid to ignore the fuel tank warning light and not tank up as and when required.
