[vivaldirules]

I bought my 500 ten months ago and immediately installed a 2 Gb Sandisk SD card in it. With the internal memory filled with books and a few more on the SD card, I was recharging every couple of weeks or so. Since then I've regularly been adding more books to the SD card and not removing any. Over the same time, my recharging had to be done increasingly often until early this month this reached two or three recharges a week. I assumed something was wrong but I decided to first remove the SD card and go without it. That was a week ago and I have not recharged yet and, in fact, I still have four bars on the battery indicator. I know the fact that SD cards tend to drain the battery more has been mentioned, but I was never aware of how serious it can be. My impression from this experience is that it makes a huge difference how much you have on your SD card. The closer I got to filling the card, the recharge frequency increased dramatically. I may try reinstalling the card but removing half of the books on it just to see if this nonlinearity is correct.