#Bulb

Peter writes:

I drive a 2010 Toyota Prius. From top to bottom, I’m thoroughly impressed by the technology in this car. And yet this engineering marvel is so easily disabled by its inferior owner leaving a dome light on overnight and draining the 12V battery.

Is there any technical reason cars allow the 12V battery to be drained down beyond the point where the car will start? Who needs that extra 6 hours of dome lighting?

John writes:

Hi Sajeev!

I’m still only three years into the car business and I still haven’t wrapped my brain around one thing: xenon headlamps. As a used car manager I’ve replaced plenty of xenon bulbs (pricey) and even some ballasts (really pricey).

Are you sold on their usefulness? To me it seems like a giant waste of money.