Sounds like the symptoms that suddenly struck me again last evening. I was at an alternator and starter repair shop when I discovered my troubles, the place didn't accept plastic so I jumped into the Volvo to find a cash machine while the mechanic replaced the drive assembly on a stater for my new (non-Volvo) aquisition. How's that for irony? Today I tried to run a few errands with a fully charged battery and ended up walking. Eventually I got the Volvo home, got the alternator off (only burned my arm once) and took it to the shop. They determined that it wasn't a failure of the regulator/brush assembly that i replaced a couple of months ago but probably the the diodes. It was too late inthe day for them to start tearing it apart today but I was relieved that I didn't have to start looking for some mysterious electrical gremlin.