Galaxy Z Fold8 and Z Fold8 Ultra battery: Samsung's longest-lasting Folds yet

The Galaxy Z Fold8 and Galaxy Z Fold8 Ultra both comfortably lasted a full day in our everyday use. That makes them worth considering if you want a large folding screen for getting things done during the day and watching something in the evening.

The Galaxy Z Fold8 has a 4,800^[1] mAh battery and is rated for up to 26 hours of video playback. The Galaxy Z Fold8 Ultra has a 5,000 mAh^[2] battery and extends that rating to up to 27 hours.

The Fold8 is a good fit if you want a lighter phone to carry: at 201 g, it is the world’s lightest book-style foldable phone. The Fold8 Ultra is the choice for the largest battery and longest rated video playback time in the Galaxy Z Fold range.

In our experience, both phones comfortably lasted a full day. The Fold8 Ultra handled messaging, web browsing, camera use and time on mobile data, with enough charge remaining for lighter use the following morning.

A single full charge could take the Galaxy Z Fold8 from Friday morning into Saturday afternoon with lighter use, especially if you spend more time on the cover screen.

Screen brightness is one of the biggest variables for battery drain. The main and cover displays peak at up to 3,000 nits to maintain visibility in direct sunlight, and they adjust automatically based on ambient light. Naturally, spending a full day outdoors can draw more power than staying inside.

In our experience, that still doesn't stop either phone from comfortably getting through a normal day spent moving between indoor and outdoor use.

The Galaxy Z Fold8 and Z Fold8 Ultra both handle demanding main-screen use comfortably over the course of a day.

In terms of productivity when you’re at work, it could mean keeping a document open beside a browser or referring to notes while replying to a message. Video streaming can keep the main display running for long stretches, while gaming places a sustained load on both the display and the processor.

In our experience, a full day of mixed heavy use on the main display still leaves both phones with battery to spare by evening. Using the cover screen more often for lighter tasks can stretch that further, and both phones can reach into a second day with lighter use.

Yes. Reaching up to 27 hours of rated video playback, the Galaxy Z Fold8 Ultra outlasts every previous model. Its 5,000 mAh battery is also the largest Samsung has ever put in a Galaxy Z Fold.

The Galaxy Z Fold8 sits just behind it at up to 26 hours from its 4,800 mAh battery. This puts it ahead of every older model, including the Galaxy Z Fold7, which was rated for up to 24 hours of video playback.

Looking back, rated video playback has steadily increased with every generation: 20 hours on the Fold4, 21 on the Fold5, 23 on the Fold6, and 24 on the Fold7. This year's devices add an extra two to three hours on top of last year's benchmark.

The up-to-27-hour figure is a video-playback rating based on lab testing. It is estimated from battery capacity and measured power consumption while a stored 720p video plays on the main display, with Bluetooth earphones connected and the phone using default settings over LTE.

That is a different workload from streaming video or using a mixture of apps through the day. Your apps, connectivity and screen brightness will affect how long a charge lasts.How do bigger batteries fit into thinner, lighter Galaxy Z Fold designs?

Both 2026 models rely on silicon-carbon battery technology. This chemistry allows for higher energy density, storing more capacity in the same physical space compared to the older cells used in previous Folds.

You can see the result in the physical dimensions. The Galaxy Z Fold8 Ultra measures 4.1 mm thick when unfolded and weighs 215 g while housing a 5,000 mAh battery. For comparison, the older Galaxy Z Fold7 measures 4.2 mm unfolded at the same 215 g and has a 4,400 mAh battery. That’s a 600 mAh increase while the unfolded thickness drops by 0.1 mm.

The Galaxy Z Fold8 packs a 4,800 mAh battery in a 201 g chassis. That's 400 mAh more than the Galaxy Z Fold7, despite the Fold8 weighing 14 g less.

Using a compatible adapter, both models support 45W Super Fast Charging 2.0^[6] wired charging. Thirty minutes on the cable gets the Galaxy Z Fold8 Ultra to 67% and the Galaxy Z Fold8 to 63%. A quick half-hour charge while getting ready in the morning is generally enough to cover a full day's use.

Both phones also support 20W wireless charging, compared with 15W on the Galaxy Z Fold7. They support Wireless PowerShare^[5], allowing you to use the back of the phone as a charging pad to top up compatible earbuds, smartwatches or phones.

In our charging tests, both phones closely matched the 30-minute figures. Each reached roughly 95% after an hour and a full charge in just under 70 minutes.

Samsung includes a Battery protection menu to help minimise long-term wear.

The phones also come with Power saving mode, which can make them last longer on a single charge, reducing how often you charge the battery. This stretches your remaining battery life by reducing background activity, screen brightness and refresh rate, and CPU performance.

The Adaptive power saving setting removes the need for you to manually trigger power saving mode by automatically enabling it based on your usage patterns.

Yes. In our everyday use, the Galaxy Z Fold8 and Fold8 Ultra comfortably lasted a full day with charge remaining. Their rated video playback times are up to 26 and 27 hours respectively.

This endurance is backed by the largest batteries yet in the Galaxy Z Fold line (5,000 mAh and 4,800 mAh), along with 45W charging support that can replenish more than 60% of the battery in just half an hour.

^{[1] Typical value tested under third party laboratory conditions. Rated minimum capacity of the Galaxy Z Fold8 is 4,660 mAh.}

^{[2] Typical value tested under third party laboratory conditions. Rated minimum capacity of the Galaxy Z Fold8 Ultra is 4,854 mAh.}

^{[3] 45W charger sold separately.}

^{[4] 20W wireless charger sold separately.}

^{[5] Wireless PowerShare: Works with most Qi-compatible devices. Different devices may charge at different speeds. Need minimum of 30% to use.}

^{[6] Super Fast Charging (SFC) 2.0 requires a USB Power Delivery (PD) 3.0 compatible device supporting Direct Charging.}