Uh oh! An Adafruit MCP73833 LiPoly charger… Apparently it was reworked a few times at the factory. the USB connector wasn’t properly aligned or even connected on two of the five leads, and the chip was a bit of a mess, but seemed to be OK….so I repaired the USB connection, and the red light came on, so that was all great until I connected the battery, and POOF! Oh well… apparently something else was going on too. Anyway, the other unit was fine, and I expect that they’ll be good sports about getting me a good one.
UPDATE: As predicted, Adafruit was awesome and they’re getting a new one to me.