Samsung took its time giving its Galaxy Z Fold phones bigger batteries. The Fold 3 had a 4,400 mAh battery back in 2021, and the company stuck with that capacity all the way through the Fold 7 in 2025. That’s five generations without an increase, or six if you count the Galaxy Z Fold Special Edition (which got a limited launch).

The Galaxy Z Fold 8 Ultra finally brings a 5,000 mAh battery thanks to silicon-carbon technology, and some owners upgrading from older Folds have plenty of good things to say about it.

We've noticed the better battery life at SamMobile too, though the Fold 8 Ultra can struggle to last as long as the Galaxy S26 Ultra in our experience, despite both having a 5,000 mAh battery.

One Reddit user who upgraded 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 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. 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 battery improvement over the Fold 7 was much bigger than the jump from the Fold 6 to the Fold 7 (no surprise, since the Fold 7 had the same 4,400 mAh battery as the Fold 6).

They had owned the Ultra for three weeks and described getting almost nine hours of screen-on time during a day at home, mostly playing games and watching movies on the inner display. The phone still had 15% battery left at bedtime.

There’s similar praise for the Galaxy Z Fold 8, which packs a 4,800 mAh battery. One owner specifically using the non-Ultra model reported eight to nine hours of usage between charges, compared with seven hours or less on their Fold 7.

An Ultra owner who switched from an iPhone 17 Pro Max was less impressed. They said battery life wasn’t terrible, but it wasn’t as good as they had hoped, especially after seeing other owners report much better results. They had been using the phone for about a week when they posted.

So there are happy owners and disappointed ones, as there usually are when it comes to battery life. Our own experience falls somewhere in between: better than before, but still behind Samsung’s top S-series phone.

Let’s just hope Samsung doesn’t make us wait another five generations for the next increase.