Due to lack of funds, I have been one of those people that wait till they have to do something about their car, body, home etc before ponying up some scratch. I had left the dome light on in my car (or as I like to call it "the bedroom/entertainment room mood lighting") and almost completely killed the battery. There was enough juice left to crank the engine over but just barely. I assumed that the alternator would charge it back up but after driving 2, 2 hours stretches with no improvement in cranking capacity, I started to think I needed a new battery or perhaps alternator or starter or.....(begin cycle of fear)
One disadvantage of living in your car is that you live in your car. If it goes into the shop for a few days then you have to find somewhere else to sleep ontop of hauling all your shit out so the mechanics don't steal you precious vodka. Despite not wanting to spend any money, I knew that putting this off was less than intelligent. Autozone (and most auto parts stores) will test your battery for you (although I can't help feeling that the machine is just trying to sell batteries for the store). Apparently, running the battery down with the light killed it. The salesman informed me that if you run a battery down, you shouldn't rely on your alternator to charge it back up because that's not what they are designed for and it can actually ruin the alternator. I didn't want to take the chance of not getting to work or harming something else because I was looking for a charger so I bit the bullet and spent $112 for a new battery. It was 4 years old anyway so it seemed like due time.
My lesson from this is to start preemptive care on what I own or my body (ugh, I hate going to the doctor). I'd rather replace the water pump, for example, before it goes bad and leaves me or a loved one stranded on the side of the road. Budget, plan, spend and prevent. Man, I really don't want to go to the doctor. Shit!