Galaxy Z Fold 8 Ultra battery life is drawing praise from many long-time Fold users after Samsung increased capacity to 5,000 mAh using silicon‑carbon technology. Owners upgrading from older Fold models report noticeably longer screen-on times, though independent testing found the Fold 8 Ultra can still lag behind the Galaxy S26 Ultra despite both phones having 5,000 mAh batteries.
Samsung kept the same 4,400 mAh battery from the Galaxy Z Fold 3 in 2021 through the Fold 7 in 2025—five generations without a capacity increase, or six if the limited-launch Galaxy Z Fold Special Edition is counted. The switch to a 5,000 mAh cell in the Fold 8 Ultra represents the first major jump in battery capacity for the lineup.
Galaxy Z Fold 8 Ultra battery life: owners’ reports
Several owners upgrading from recent Folds shared positive real-world figures. One Reddit user who moved from the Galaxy Z Fold 6 reported eight hours and 51 minutes of screen-on time since their last charge, with 22% battery remaining; they said they hadn’t charged overnight and were already using the phone into a second day. “Coming from the Fold 6, this feels like a massive improvement,” they wrote, adding that most of their usage was on the inner display and they weren’t using power saving mode.
Another owner who has used every Fold since the Fold 3 said the improvement over the Fold 7 felt much larger than the jump from the Fold 6 to the Fold 7. After three weeks with the Ultra, they described getting almost nine hours of screen-on time during a day at home—mostly gaming and watching movies on the inner display—and still having 15% battery left at bedtime.
There is also praise for the standard Galaxy Z Fold 8, which uses a 4,800 mAh battery. One owner of that model reported eight to nine hours of use between charges, compared with seven hours or less on their Fold 7.
Not everyone is impressed
Not all feedback is glowing. An Ultra owner who switched from an iPhone 17 Pro Max said battery life wasn’t terrible but fell short of expectations after seeing other owners report much better results; they had been using the phone for about a week when they posted their impressions.
Overall, reported experiences vary: many older Fold owners welcome the battery upgrade, some users see substantial gains, and some find the Ultra’s endurance only a modest step up. Our own testing places the Fold 8 Ultra between those views—better than previous Folds, but still behind Samsung’s top S‑series phone.
