A few days ago I read The Verge's Nexus 4 review. Reviewer found the battery life to be pretty impressive!
Nexus 4 review | The Verge
"Battery life was also top notch. I'm used to getting just about a day of use on my Galaxy Nexus (that's taking it off of the charger around 8AM or 9AM, and putting it back on around 2AM). Some days it doesn't quite make it that long, depending on my workload. The Nexus 4 fared much better. At the time of this writing, I've had it off of its charger for 10 hours and 30 minutes and it's still got 45 percent battery life. Yesterday before I plugged it in, I'd had it off the charger for 16 hours, with 18 percent of its juice left. To say it's holding up for full work days would be an understatement; even with heavy use, this battery more than pulls its weight."