At last we carve out the (mightily adhered) 5-cell battery.

Well, five-ish cells. With a nominal voltage of 11.41 V, the two outer pairs are wired in parallel and together have the same charge capacity as the center one, to yield three ~3.8 V cells in series.

You'd better hope your "Pro" career is short; this battery replacement is a doozy.

The battery board hosts a TI BQ20Z451 (a possible variant of the BQ20Z45-R1 line, seen in MacBook Pros forever)

Listing a 49.2 Wh capacity, this battery seems a little piddly compared to the Function Key edition's 54.5 Wh—especially considering it's driving a lot more functionality (pun intended).

Dotting our i's, we slap these batteries on a scale: the Function Key-equipped MacBook Pro battery weighed in at 235 grams, while this battery weighs just 197 grams.

The weight disparity probably helps account for a lighter Touch Bar edition, but the battery seems to rate more watt-hours than the decrease in weight would suggest.