Originally Posted by AndroidSPCS

Make sure the cover is on properly and snug. If it's not on snug the battery could shake loose and cause the phone to power off.

I looked at a girl's LG Dare, which has a similar type of battery cover, and I could see that she crammed the cover on, which caused a couple of the battery cover notches to fold in on itself, thus not securing the cover properly. Her phone would turn off randomly because the cover was not secure.

Most people don't pay careful attention to details like that, so little things like that could easily cause problems. I hate the battery cover design but I'm very careful when snapping it back on so it hasn't caused me issues.