tl;dr: a testing certificate for a Google phone going by the model name “GH2MB” (similar to those of the Pixel 7a) is suggesting that the Pixel 8a might be getting a 4,942mAh battery. For a comparison, the Pixel 7a has 4,385mAh, the 8 has 4,575mAh and the 8 Pro has 5,050mAh.
God I hope so. My Pixel 7 is mostly good, but the battery needs charged in the afternoon. And I’m far from a power user.