Hi Murf1, thanks for the reply.
Yep, we could turn off 3G when not on WiFi, but turning off the 3G doesn't solve the problem; it only mask the symptom.
We bought an Android phone so that we (my family) can connect to the internet anywhere there's a 3G signal. Plus, we use Google's Latitude to stay in touch with our children's location and they ours. However, we have been turning off our 3G when we are not moving about.
Our LG OVs will last 14+ hours with 3G enabled. Our OEs last 7+ hours before the 20% mark. I think there's a HW issue with the 3G. I'm guessing the problem is related to the antenna somehow. I've got no proof; just a guess.
Thanks again! :-)