So I have been using the kindle app for all of my reading needs. However, I have noticed it is using a high amount of battery power. Browsing the web for an hour will use about 6 to 8% battery power, but an hour of kindle reading will use about 10 to 15%. Is this normal? Are there any settings I can change to lower the amount of power used? Does iBooks use a smaller amount? Any input on this issue is appreciated. Thanks everybody!