The iOS 5.1 beta was seeded to developers not too long ago. Many had expected the update to address the battery draining issues that quite a few iOS owners were experiencing, but as it turns out that is not the case as there are still reports from those on the beta that the battery draining problem is still present.
For those unfamiliar with the issue, this problem came about when Apple released the much awaited iOS 5 which brought about many upgrades and new features. Unfortunately for some, the update caused their phones to start draining more battery than usual. This prompted Apple to release iOS 5.0.1 that was supposed to address this issue, but even after the update there were still reports of exceedingly poor battery life.
We should note that the current iOS 5.1 is still in beta which means that there could be some kinks that still need working out. It is possible that these battery woes could be addressed in a later beta or in the final version, but for now it appears that iOS 5.1 beta still needs some work done.