Re: nexus 7 version 1 help
Welcome to Android Central! You might be better off posting in the 2012 Nexus 7 forum (the 1st generation): Google Nexus 7 Tablet (2012) - Android Forums at AndroidCentral.com
When you say you wiped the entire tablet after the upgrade, do you mean a full factory reset? Did you do that from the System Settings menu, or from the Recovery Menu? And when you say you bought a new battery, did you pop off the back cover and replace the battery yourself? Since a removable battery isn't an intended feature of the Nexus 7, it's possible you might have damaged something, or perhaps loosened a connection.
See if this support page helps: https://support.google.com/nexus/tro.../3337561?hl=en
Also, see if you can boot into the Recovery Menu to wipe the cache partition: http://forums.androidcentral.com/goo...tion-wipe.html