When plugged in during driving, Nuvi turns on and off randomly, doesn't seem to be holding a charge as it shuts off when turned on and not plugged. What do you think could be causing this? it's only two years old, and I was wondering if there was something I could do to fix it. Do we think it's the batteryy, or something more?

I really like this gps and i dont think that I want to buy a new one right now