I posted this same question, apparently it actually isn't bad. Could be just a single bad review. Phil's Pod cast said along the lines of his battery was ok nothing out of the normal. I think it all really comes down to usage and how you use it. " When it comes to battery life, the Nexus 4 is also performs just below the One X and the iPhone. Under normal use, I could go a day before having to charge it. If I was using the handset non-stop, I?d have to charge the Nexus 4 before I left work. This is good battery life, but not exceptional." - wired.
Edit:
Battery life is yet another segment of the performance that's confused us. Since the Nexus 4 uses the same 2,100mAh battery (and power-friendly Krait chip) as the Optimus G, we expected to record essentially the same runtime. Much to our surprise, however, it was considerably worse in both our tests and our real-life use. Our standard video rundown test, which consists of looping a movie at 50 percent brightness with WiFi on (but not connected) and normal pull notifications for email and social media, lasted for five hours and 18 minutes before the battery died. Our anecdotal tests -- in which we do a moderate amount of email, social media, messaging, web surfing and take a few pictures and make some phone calls -- almost got us a full day of use, but your overall result will definitely depend on how bright you set that display. Regardless, the experience we had with both of our review units is still a stark contrast to the Optimus G, which lasted over eight hours in the video rundown test and 20 hours with moderate use. - Engadget.
Featuring a 2,100 mAh battery we found that the Nexus 4 handled a day easily however this was with very limited use so wait for the full review to find out if it can cope with an average days use. - T3
Despite driving a very high res panel, Google is able to deliver relatively competitive battery life with the Nexus 10. Battery capacity is around 80% the size of the 3rd gen iPad and battery life is around 93% of what Apple delivers here. Over 10 hours would be nice to have, but 8 hours of use in this test isn't bad at all. We'll have to do more testing to understand Exynos 5's power behavior a bit better, but so far it doesn't seem that the platform is all that bad from a power consumption standpoint. It remains to be seen how gracefully the Nexus 10 will handle being taxed heavier. - ANANDTECH