My Battery is Dead

I've decided that the original battery on my Verizon XV6800 is now dead. I've had this battery for about 18 months now, but my phone is relatively new because I received a replacement from Verizon.

I have an extended battery so I plan to use that moving forward. I don't think I'll be replacing the original battery anytime soon. Why? Mainly because I use my XV6800 as a GPS quite often and I also use it heavily as a mobile internet device (MID). These services can drain the battery quickly.

So, if I had an iPhone that was also 18 months old, would my battery be dying?