battery usage

Hi All
I bought the LG GW-825V (Hong Kong Version) earlier and found the battery drains up very rapidly

today i just used it for reading ebooks for 2hrs and talked 5-6 phones (each 1-2 min, voice only), and the battery drained from 6x% to less than 10%. no other apps and no bluetooth, no wifi, no gps

when back to workplace i plugged it to the USB port of the pc for charging and till now 6hrs has passed the battery is just 37%. i am in the view that the battery drains much more quicker than charging thru pc USB power, what do you guys think?

you know, I thought that was hogwash, but that seems true, the first week I barely made it through the day, sometimes not even then, but this weekend, I made it two days without a charger, on moderate usage.

Vanillagorilla is right though, the wall charger is a must, unless you plan to use it while sitting at your computer, the usb port doesn't charge the phone all that fast, and barely charges the battery when left overnight.