I was in a bus with heavy traffic, so I pulled out Meteor Blitz and Mirror's Edge for 4 hours, draining the battery to 81%. When I plugged it into the wall with the included 10W wall charger and began surfing the web.It took about an hour to get the battery up to 90%, but then the charging sped up exponentially, taking about 15 minutes to charge the last 10%. Does this mean that my battery is functioning abnormally, or is this something that just happens to iPads? The display brightness was set to automatic (probably about 60%), WiFi was off, 3G was on and connected, and Bluetooth was on.