unless you have an emergency. NEVER NEVER NEVER, plug your cellular phone into a car charger - unless you know for certain its not a quick / snap charger. Those chargers murder a battery.
Go to Crackberry and purchase a dock charger with a spare battery charger. Purchase 2 spares and rotate them out with you daily. When or if your Storm gets low on juice, pop in a fresh battery. A spare fits comfortably in any pocket.
This practice always served me well in the days were a couple long winded conversations on social outings killed my battery. I was never without service when I carried a spare with me.