Here's the 1S lead soldered onto the cell. Notice the lead is a lot shorter than previously.
That's because I got some liquid tape, and didn't have to leave enough room on the wires to put shrink wrap.
I used a piece of craft stick to daub the liquid tape onto the exposed tab and solder connection.
Here's what the final unit looks like. The liquid tape seems to cover pretty well.
The battery doesn't fit into the Celestra charger as is, because the leads are a bit too short and the cell is a bit too wide. Using a 1S extension solves things nicely.
And it's certainly light enough... Flying the Night Vapor smoothly I was able to get 17 minutes on this battery, about 4mA per minute. I was impressed!
Update: this connector is a "Molex PicoBlade (grid: 1.25mm)"