If you have any kind of battery doctor or similar app installed on your devce, first start off by uninstalling it. They are trouble.
Next you might have ad ware if this is a popup message.
There is a one step process to hopefully cure all the problems or there is a longer way with many more steps.
The quickest fix is to bite the bullet and do a factory reset. If you decide to do a factory reset, do not restore data with your Google account when you are setting your device back up. This could restore the problem you are having now.
.if you want to try it with the longer method without wiping your device, post and I'll give then to you. Keep in mind it doesn't always fix it without doing a factory reset.