This afternoon, I had to drive something to the post office. Which would have been no big deal except that when I went out to my garage, I found that the battery in my car was dead. Some idiot (i.e., me) hadn't fully closed the right rear door on the passenger's side when he (i.e., me) last drove the car, which was Tuesday afternoon. The dome light had been on for over 48 hours and that had run down the battery.
Actually, it still wasn't a big deal. I called Triple-A and a man was there in fifteen minutes to give me a jump and send me on my way, just in time to not get to the post office before it closed. But I got to thinking…
Obviously, I need to be more careful about this in the future, especially since this is probably the third or fourth time I've done this in my life. (In my defense: Once, it wasn't me, it was my assistant when she took the car to be washed. And once, it was because I closed the car door on a seat belt that was hanging out.) But I'm curious why this is even a problem at all with cars…or is it just with some cars?
Almost everything I own that "charges" has some sort of battery meter, often with a little warning buzzer if it gets too low. Why doesn't my car have a little meter that stops the battery from being drained if it's about to get too low to start the car? Do some cars have that? It would seem like a feature that could be installed for around five bucks, which means they could make it a $300 option and we'd all pay.
Here's an idea that I thought of once while waiting for the Auto Club in this situation. A car should have two batteries. One, which we'll call Battery A, works just like your standard car battery: As you drive, it charges and it's what starts the engine in the morning. But you'd also have Battery B, which is a smaller battery, just big enough to start the car twice. It gets charged the same way but it doesn't power anything on its own. It just holds a charge, waiting until it's needed.
When the moment comes that Battery A is dead — say, because you stupidly didn't close the right rear door on the passenger's side two days earlier — you flip a switch. Or maybe there could be an automatic connection…but either way, Battery B goes online in the car and it starts the engine. Then once Battery A is charging again, Battery B goes offline or you take it offline…and later, it recharges so it's ready the next time you need it.
Why don't they have this? Or do they have it? What am I missing here? (Even though I used to sometimes fix my old '57 T-Bird myself, I'm not too savvy about cars. When I had to look at the engine, I used to try peeking through the ignition keyhole.)
Yes, I know there are little packs of drycell batteries one can buy that will jumpstart your car. There are cables that will connect you to an AC outlet via your cigarette lighter. I even have a little portable powerpack that I could have used to jump the battery if I'd remembered to recharge it in the last year or two. I'm wondering why no one just builds something like that into vehicles. They're putting DVD players into back seats now. Couldn't there be an extra battery in the trunk somewhere? Or at least a little gauge that stops the main one from draining to the point where it's useless?