Even if you left it going non-stop with WiFi going you should get 2-3 days out of the sucker. I had a Nexus 7 from 2012 and the battery life was great. If yours is sucking down that much juice, you may want to check your battery consumption and see what is taking so much. You may have a vampire app that runs full time in the background keeping your processor running hard. Otherwise, you certainly have a hardware issue since it shouldn't be depleting your battery this quickly.