The Galaxy Watch Ultra 2 carries an 800mAh battery, 35% up from the original 590mAh cell, inside a case 12% thinner. The endurance Samsung quotes did not move. Gadgets and Wearables caught it: "Yet Samsung is still promoting up to 100 hours in power saving mode and 48 hours in exercise power saving mode, the same headline figures attached to the previous Ultra."
Samsung says the bigger cell, the Snapdragon Wear Elite chip and One UI 9 Watch should together deliver true multi-day outdoor battery life, which is a different claim from a longer number on the box. The same piece leaves it where it belongs: "It does, however, leave Samsung with an obvious question to answer when the first independent battery tests arrive."