The framework battery is not 3.7v. Cells can be combined in series (s) or parallel (p). You would describe a battery similar to 10s3p, meaning 10 cells in series (37 volts) in 3 parallels, for a total of 30 cells.
The frame.work battery is a 15.4 VDC battery, with a capacity of 3678 mAh. Meaning its Watt-hours is 15.4 x 3.678 or ~56.6 Wh.
I uh, .. missed that part.