Pre Central has confirmed that the Palm Pre's battery will be identical in size to the Centro's, meaning that it will likely be limited to a modest 1150mAh-1350mAh capacity.
Given the large, ultra-sharp screen, graphically intensive OS and constant requests to its tightly integrated online services, one would expect that the Pre would be something of an energy glutton—at least moreso that the Centro and 800w, which share its battery. Given that even the Treo Pro, with a 1500mAh battery, isn't good for much more than two days of regular use, it looks like the Pre might fall into the iPhone/G1/Storm trap of requiring a full charge every night, or worse.
For reference, the iPhone's battery is a more generously apportioned 1400mAh unit, where the G1's power comes from a sad little
10001150mAh lithium polymer. PreCentral deduced the Pre's 1150mAh figure from the existing capacities of this battery type, whereas PalmInfoCentral was told directly by a PR rep to expect 1200mAh.
The news isn't all bad though, as there are already a plethora of cheap aftermarket batteries that were designed for the Centro and 800w, and will therefore fit the Pre. Additionally, if you're upgrading from another Palm device you'll be able to carry your current batteries as a backup. [PreCentral via PalmInfoCenter]