Check the date of the android core ai update in Google play. That was draining my battery (actually since ui7 rollout) after much searching and test, found a few reviews mentioning to uninstall the updates (settings > apps > android core > uninstall updates) for the app (reverting to stock) and my battery life has considerably improved. I'd consider myself to be a low to medium ai user and have not seen any issues with removing the updates. Just seems like it was running in background ALL the time and killing battery life!
