A test: battery status while charging and navigating: Telenav and Google Nav
A little background: I'm on my third Epic 4G, thanks to constant problems. Ever since the first software update, I've had random restarts, a week of nearly non-stop restarting 2 minutes after reset, phone locking up as soon as I bring up the lock screen, requiring a battery removal, and all sorts of minor issues while using the phone.
One of the oddest things I've noticed is that many times, my phone seems to be losing power quickly if I use GPS while charging my phone in my car. I decided to test this briefly at home. Here's what I found:
With only sound and GPS on, using the 3G network, maximum brightness, screen on the whole time, and using Telenav's navigation app for 1 hour, I lost 20% of my phone's battery charge while charging through a USB port.
Same settings, this time with Google's Navigation program, I gained a 12% on my battery's charge after one hour.
Also of note: Using Telenav, the back of my phone was nearly scorching hot, while with Google Nav it was between warm and hot.
If anyone else feels like running a similar test, please post your results. This doesn't sound normal to me at all.