Jim, I think you're right in regards the 18650s. It's 4:30 PM PDT and windy is reporting 11.6 V, which correlates well with 3x Lithium. As has been seen in the past week or so, Windy has been really strong into the KFS kiwis.
If I were to guess:
* Clock speed of processor was lowered (hence the slower CW and anemometer pips)
* Battery was changed as you observe
* Antenna was fixed up.
If so, bravo to the ops!