So, I'm back from vacation.
After sitting, fully charged, for a week my BB-600 cells have grown some fuzzy coatings. Some of this appears to actually be fuzz -- some kind of textile fibers, but some appears crystalline. The following pics attempt to document the effect, but it is spotty (in the sense of inconsistent) some cells are coated, others are fine. I am concerned that this may be a symptom of bad seals at the posts.
Bought an Intermatic timer (for my modified badboy charger) but realized I could use it with the automotive charger to make charging and cell testing a bit easier. Here we are putting an initial charge on battery number 4.
After sitting for a week there was some concern that the cells would have self-discharged quite a bit. The voltage had decayed a lot, but when I load tested them using the motor as a load, I got 90 A-hrs out and they still aren't fully discharged. This is very good!