Battery life remains one of the top priorities for smartphone users in 2025—and Samsung continues to deliver a wide range of devices with varying battery performance depending on your usage style, display size, and chipset efficiency. Whether you’re a power user who games and streams daily or someone looking for a long-lasting phone for calls, messaging, and occasional browsing, there’s a Samsung phone that suits your needs. But the big question is: Which Samsung phone actually lasts the longest on a single charge?

To answer this, we compared real-world usage and lab-tested results across Samsung’s 2025 lineup, including flagship, mid-range, and budget devices. Our findings show that battery performance isn’t just about mAh size anymore—it’s also about chip optimization, display efficiency, software tuning, and AI-based power management.

Leading the pack in battery endurance is the Samsung Galaxy M15 5G, boasting a massive 6000mAh battery. This phone lasts well over two full days with moderate usage and easily pushes past 10 hours of screen-on time in daily tests. It's a favorite among users who prioritize longevity over high-end features. The power-efficient AMOLED display and MediaTek Dimensity chipset make it one of the best value phones for battery-conscious buyers.

Next up is the premium Galaxy S25 Ultra, which features a 5000mAh battery. On paper, it may seem smaller than the M15, but thanks to the Snapdragon 8 Gen 4 for Galaxy chip and adaptive refresh rate that scales down to 1Hz, the S25 Ultra still offers impressive all-day performance, even with heavy use. Users can expect 6.5–7.5 hours of screen-on time, making it a powerhouse for productivity, content creation, and gaming without frequent charging.

Surprisingly, the Galaxy A55, a mid-range favorite, also holds its own with a 5000mAh battery paired with a 120Hz Super AMOLED screen. With less demanding tasks and efficient app handling via One UI 6.0, this device routinely delivers 8–9 hours of screen-on time and lasts more than a full day for average users. It's ideal for students or professionals who want great display quality and long life without the flagship price.

On the foldable front, the Galaxy Z Fold6 and Z Flip6 offer unique battery dynamics due to their form factors. The Z Fold6 packs a 4800mAh battery, which is solid given the dual-screen setup. With intelligent software optimizations and split-screen multitasking, it still manages 5.5–6 hours of screen-on time, although not as long-lasting as standard phones. The Z Flip6, with its compact 3700mAh battery, is the weakest in this comparison, offering around 4.5–5.5 hours of screen time—sufficient for casual users but not ideal for heavy multitaskers.

It's also worth noting that all Samsung phones in 2025 benefit from AI-powered battery optimization features in One UI 6.0. The system learns your usage habits and adjusts background tasks and refresh rates accordingly to reduce unnecessary drain. Features like Sleep Mode, App Hibernation, and Adaptive Power Saving significantly extend standby times, especially on One UI-tuned mid-range models.

If you’re looking to maximize battery life without breaking the bank, refurbished models like the Galaxy M14 or Galaxy A34, available with high-capacity batteries and efficient displays, are a great option. You can even Buy Refurbished and Second Hand Samsung Phones In India at affordable prices while still enjoying solid battery life, One UI support, and warranty-backed reliability.

In conclusion, if maximum battery life is your top priority, the Samsung Galaxy M15 5G remains the king in 2025 with its 6000mAh endurance beast. For flagship users, the S25 Ultra offers the best balance between power and longevity. Mid-range users will be more than satisfied with the Galaxy A55, while foldable fans may need to compromise slightly on battery in exchange for form factor flexibility. No matter your budget, Samsung continues to offer smart battery optimization and excellent hardware-software integration to keep you powered up longer.