Yes. Live wallpapers use your phone?s CPU and GPU to render itself. So, it will decrease your battery life. Less than 2% in most case. The effect is so insignificant that there is no need for you to worry about whether to have one or not. However, there are some live wallpapers that give the battery a more significant beating than others. You can check how much battery your live wallpaper uses by going to Settings > About > Battery > Battery Use. If you see that it takes less than 5%, it?s absolutely ok.