5 Best Battery Life Phones in UK Review and Real Usage Guide

Why Battery Life Still Matters in 2025 Despite 2025's innovation in foldables, AI integration, and ultra-slim designs, battery life is still a major concern. Whether you're a gamer, traveler, or just a heavy WhatsApp user, a phone that dies before bedtime is a dealbreaker. In this article, we’ve tested and ranked the top 5 phones with the best battery life, specifically focused on real UK users.

All phones are rated based on:

• Real-world battery test (web usage, video streaming, screen-on time)

• Charging speed

• Battery capacity (mAh)

• Processor efficiency (Snapdragon, A18 Pro, etc.)

Let’s dive into the list that keeps your phone going for over a day — and in some cases, even two full days.

Battery Life Comparison Table

Asus ROG Phone 9 Pro – Best Battery Life Overall

• Battery: 5800mAh

• Tested Life: 20 hours 34 minutes (adaptive refresh rate)

• Charging: 65W (0 to 74% in 30 mins)

If battery life is your top priority, nothing beats the Asus ROG Phone 9 Pro in 2025. With nearly 21 hours of screen-on time, it’s the current king for long sessions — gaming, streaming, or multitasking.

Even with its blazing-fast 165Hz display and AniMe LED lights, the phone barely breaks a sweat thanks to the Snapdragon 8 Elite chipset. Combine that with 65W charging, and you’ve got a phone that not only lasts long — but charges quick too.

Pros:

• Top performance for gaming and media

• Largest battery capacity on the list

• Best-in-class cooling system

Cons:

• Pricey in the UK market

• Slightly bulky

OnePlus 13 – Best for Fast Charging + Battery

• Battery: 6000mAh

• Tested Life: 19h 45m

• Charging:100W wired, 50W wireless

The OnePlus 13 balances power and longevity perfectly. With a massive 6000mAh battery, it gets you almost 20 hours of use and is topped up in under 30 minutes with 100W charging. For users who want both speed and staying power, this is the pick.

Pros:

• Fastest charging in this category

• Premium design and flagship build

• Dual-SIM and strong performance

Cons:

• No official IP rating

• Wireless charger not included

iPhone 16 Pro Max – Best iOS Battery Life

• Battery: ~4685mAh

• Tested Life:17h 17m (real-world usage)

• Charging: 30W wired, 15W MagSafe

Apple’s iPhone 16 Pro Max sets the benchmark for iOS battery efficiency. The A18 Pro chip delivers an ultra-optimized performance, making the smaller mAh count irrelevant. Two-day battery life is within reach for light to moderate users.

Pros:

• Bright and large 6.9" display

• Excellent camera and iOS 18 features

• Great battery-to-size optimization

Cons:

• Slower charging than Android flagships

• Premium pricing in the UK

Samsung Galaxy S25 Ultra – Top Android Flagship

• Battery: 5000mAh

• Tested Life: 17h 14m

• Charging: 45W wired, Qi2 wireless

Samsung’s latest powerhouse, the Galaxy S25 Ultra, isn’t just a productivity beast — it’s also a battery champ. With the Snapdragon 8 Elite and AI power-saving features, it beats the S24 Ultra by nearly an hour.

Pros:

• Gorgeous 6.8" QHD+ anti-reflective display

• Galaxy AI & S Pen support

• Long software support (7 years)

Cons:

• Expensive

• No charger in the box

Moto G 2025 – Best Budget Battery Performer

• Battery:5000mAh

• Tested Life:18h 32m

• Charging: 30W wired

For those wanting a budget smartphone with serious endurance, the Moto G 2025 is a winner. At under £200 in the UK, you’re getting close to 19 hours of use on one charge.

Pros:

• Affordable and efficient

• Near-stock Android UI

• Decent display and design for price

Cons:

• No 5G or wireless charging

• Plastic body

Also Worth Considering

Google Pixel 9 Pro XL – Combines smart AI-based battery optimisations with clean Android 15. Offers solid performance and around 16 hours of screen time. Excellent cameras and Pixel-exclusive features.

Samsung Galaxy S25+ – A slightly more affordable version of the Ultra. Same 5000mAh battery, delivers around 16.5 hours of battery life. Great for those who want flagship power at a better price point.

FAQs – Everything You Need to Know

Which phone has the best battery life in 2025?

The Asus ROG Phone 9 Pro currently leads with over 20h of battery life in real-world tests.

Does higher mAh mean longer battery life?

Not always. It depends on software optimization, processor efficiency, and screen usage.

What’s the best phone under £300 for battery life?

The Moto G 2025 offers excellent battery life (18h+) for a low price.

How to improve battery life on any phone?

Lower screen brightness, turn off background apps, use battery saver modes.

Final Thoughts & Where to Buy in the UK

Choosing a phone with long battery life in 2025 isn’t just about big numbers — it’s about real usage. Whether you're after a flagship beast like the S25 Ultra, a budget champ like the Moto G, or the battery monster ROG 9 Pro, there’s a pick for you.

Ready to buy? Explore the full range of long-lasting smartphones — including refurbished deals — atZextons Tech Store. UK delivery, tested devices, and budget-friendly options await.