how important is it for you to use an actual vz charger made specifically for your phone? i ask because i would plug in my blackberry (yes evil but that's besides the point) on my brothers lg charger and my phone began to hold less and less of a charge...could this have been due to using a charger that is not specifically made for my phone? i obviously need to purchase a car charger for the thunderbolt but don't know if i should buy the $29.99 vz window mounting one or just use the amazon non-oem one that comes with the case and screen protector...thoughts?