As the battery comes free, it's clear there is simply no comparison between this battery and its predecessor ... because they are exactly the same.

Model A1596—running at 3.81 V and 398 mAh, for 1.52 Wh.

That's a fair bit more than the Galaxy Buds case, which houses a 1.03 Wh battery ...

... and also more than the 1.113 Wh li-po we found in the Series 4 Apple Watch (42 mm).