The positive terminal of our '00 keeps oxiding up. In spite of a felt collar and dielectric grease it develops a corrosion node the size of a golf ball in about four weeks. The OEM clamp actually corroded away, and I replaced it with a lead universal clamp, cleaned everything and prepped it in mid September. Yesterday The Pretty One needed a jump after listening to the radio for 1/2 hour while parked. This was after two hours of high speed driving, so the connection was obviously bad enough to stop the juice.

 

What's going on; in the dim recess of my aging brain I seem to remember that this is a sign of overcharging?

 

No other symptoms.

What about a fine crack in the battery case letting the acid seep out??

Just a possibility.

I took the battery out and washed it, I saw no sign of cracks. The battery is less than a year old. Doesn't seem to use abnormal amounts of electrolyte either.

I still agree that is sounds like you have a fine crack, maybe even too small for you to detect, in the battery. In my own opnion, I would try a new battery. However one preventive measure you could try would be to purchuse some corrosion preventitive spray, also sometimes called "battery spray". It tends to work a bit better than dielectric grease.

If you replaced the battery a year ago or so, I would question why?

If you have access to a good / calibrated DVM, check the voltage at the battery with the engine running. IT should be 14.1 - 14.7. What you describe is often overlooked as overcharging. This was more common up thru the mid '70's when many vehicles still used a relay based regulator, but I have come across it on internally regulated alternators as Subaru uses.

Just a thought.