One of the chief complaints about the T3 is the dismal battery life. It's the 400 MHz processor and the screen that kills the T3's battery life, and the size of the battery you can squeeze into it is limited. Personally I don't have a problem with battery life on my T3. It lasts plenty long enough for me to survey three x-ray units (a good 6 hours of work), and my routine use isn't all that draining on the battery. But then again I'm not playing games on it all day, or using it to watch movies.
There are a number of hacks out there for extending battery life ranging from the Palm Power-To-Go external battery sled, external battery powered dongles for quick on the go recharges and tips for soldering in a new battery. I think this is one particularly cool (maybe not the prettiest) hack though. Take a bunch of Li-ion batteries from a laptop and stuff them into a cradle. Wall power charges the T3 battery or the add-on batteries, and the add-on batteries can be used to charge the T3. And it still syncs too!