The longer battery life of the second-generation AirPods Pro is partly due to the use of larger batteries in the earbuds themselves, as regulatory filings show.
Apple says that compared to the first-generation AirPods Pro, the second-generation model has an additional 1.5 hours of battery life with active noise cancellation turned on, that is, 6 hours of battery life. Listings in the 3C database show that the AirPods Pro 2 have a 49.7 mAh battery. This is 15% more than the 43.24 mAh capacity of the first generation AirPods Pro.
The second-generation MagSafe Charging Case for AirPods Pro has a 523 mAh battery, just 4 mAh more than the previous model. According to Apple, the second-generation MagSafe Charging Case for AirPods Pro provides an additional six hours of battery life, for a total of 30 hours of listening time with active noise cancellation turned on.
So it’s highly likely that the charging case’s longer battery life is actually mostly due to improvements in the earbuds. In addition to physically larger batteries, AirPods Pro’s second generation H2 chips and new detection sensors help extend battery life through greater power efficiency.