Last night around 11:30 pm or so I was driving home in the rain and stopped at a gas station. When I tried to start the car again, the starter barely cranked over, and I had to get a jump.
Today I went back to the battery guy, who did some tests and proclaimed that the battery's fine, but that there's a short somewhere in the electrical system. Unfortunately, that seems kind of plausible.
So. The first thing to do is to clean off the terminals and connectors and see if that fixes the problem. (While I'm at it I'll peer around to see if there are any obvious spots where the wires are damaged.) I really need not to get stranded someplace over the next couple of days, so until then I'll unhook one of the terminals overnight so the battery doesn't run down. After that I'll try leaving the terminals hooked up and see if I have any problems. Of course I may need to wait until it rains again to give it the real test.
If that doesn't do the trick, I'll call around and see if there's a place around that will diagnose this kind of thing and see what it costs.
The car is thirteen years old, so I have to figure out how much money I want to spend on keeping it going. On the other hand, apart from this problem it's been quite reliable. (It's a '94 Toyota Corolla with about 115,000 miles on it.)
Buying a new car has its attractions, although paying for a new car doesn't. Hmm. Well, we will see, and regardless, it won't hurt to start putting some money aside into a new car fund.