What phone battery lasts the shortest?

Tested: Big phone batteries don’t guarantee long battery life (Update: Video!)

You shouldn’t trust mAh as your sole guide to a phone with the longest battery life, it’s a much more complicated picture.

By Robert Triggs
March 29, 2021

All-day battery life is a significant checkmark for any new smartphone purchase. Here at Android Authority, we go to great lengths to test every handset’s battery life. Still, it’s all too easy to turn to a spec sheet, look at the mAh listing and make all sorts of assumptions based on a single number. This sometimes leads to us being bamboozled by the lackluster battery life from a seemingly giant 4,000mAh cell or surprised at how long a tiny battery inside phones like the Pixel 3a or iPhone SE can last.

A phone’s mAh rating is a relatively meaningless statistic when taken on its own. Battery life is actually a highly complex picture, with a wide range of contributing hardware and software variables. In this article, we’ll be digging into why you shouldn’t trust mAh as your sole guide to a phone with the longest battery life.

What does mAh mean on a battery anyway?

The mAh abbreviation you find on battery spec sheets stands for milliampere-hour. This is a unit of electric charge equal to supplying one milliamp of current (3.6 coulombs of charge) constantly for one hour. A 1mAh battery can provide 1mA of current for one hour, while a 1,000mAh battery provides 1mA of current for 1,000 hours. However, a 1,000mAh battery providing 2mAh of current will only last 500 hours. Of course, smartphones don’t last hundreds or thousands of hours because they draw much more than 1mA of current from the battery. The more current drawn by your phone, the shorter the length of time the battery lasts.

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Everything being equal, a phone with a larger battery capacity will last longer than a smaller one. However, this is seldom the case, as internal hardware and therefore power consumption varies so widely. Phone A may consume 10%, 20%, or even 30% more current than Phone B.

The unique hardware and software inside each smartphone mean that no two are ever alike. This is why simply knowing a battery’s mAh capacity doesn’t give you any beneficial information about the expected battery life at all.

Battery life vs mAh: Tested

Before we dive into the “why” a bit deeper, let’s do some testing! We ran a batch of phones with various specs and battery capacities through our in-house Speed Test G benchmark and recorded how long it takes to drain the battery. Speed Test G is a pretty brutal stress test, so these results represent the minimum screen on time you can expect from these smartphones. The results are arranged in ascending battery capacity.

There’s no clear and obvious trend from our results. We might expect to see a roughly steady increase in battery life-time as capacity increased, but that isn’t the case.

While our phones with gargantuan 5,000mAh and 6,000mAh cells offer some of the longest battery life-times under our extreme stress test, it’s actually the 3,700mAh Google Pixel 3a XL that lasts the longest here. This is all thanks to its lower-end specs, so don’t dismiss smaller batteries out of hand! Similarly, there’s just a few minutes difference between the 3,700mAh Pixel 4 XL and the 5,000mAh ASUS Zenfone 6, highlighting that capacity alone is not a guarantee of long or short battery life.

Our stress test doesn’t identify a direct correlation between capacity and battery life.

Perhaps the most notable trend from our results is that so many phones actually fall between the 3 hours 30 minutes and 4-hour mark under hefty stress. This appears to be the sweet spot that most manufacturers target, albeit with much lighter processing workloads in mind. The 2,800mAh Google Pixel 4, 4,000mAh Galaxy S20 (Exynos model), and the 4,510mAh OnePlus 8 Pro all fall within just a few minutes of each other.

Clearly, the different hardware specifications and software features strain their batteries in very different ways. But what exactly are those differences?

It all depends on what your phone is powering

The battery powers all the hardware inside your smartphone, from the processor to display and any other features packed into the handset. That much is obvious, but different pieces of hardware suck down more or less juice. Low and mid-range processors, for example, consume less power than their flagship counterparts. Generally speaking, higher performance requires more power. This is often why affordable handsets often have longer battery life than premium phones for any given battery capacity.

But as we’ve seen, even high-end flagships can have very different levels of power consumption. See the situation with Samsung’s Exynos and Snapdragon Galaxy S20 flagships. Manufacturers can also under or overclock chipsets and even alter the CPU scheduler to hit their preferred performance and power points.

There are some excellent examples of extra hardware sucking down the battery juice too. The Google Pixel 4 and its Soli radar system is a prime example of a feature that drains much more battery than a handset without it. Including a time-of-flight camera focusing system, more powerful stereo speakers, or a 4K display all impact battery life. Even something seemingly as small as charging up the S Pen on recent Galaxy Note phones adds up. These features make handsets unique, but they come with a price.

Manufacturers balance high performance and demanding hardware against all-day battery life, capacity, and costs.

The trend in faster refresh rate displays plays a big part in why modern phones consume so much power. This appears to be why the Samsung Galaxy S20 series phones stick to 60Hz out of the box, despite technically supporting 120Hz. The Pixel 4’s 90Hz mode is also linked to display brightness to save battery life. The reason being that the faster display content is refreshed, the more power the display and phone’s processor consume.

Want more examples? Did you know that the 4,300mAh OnePlus 8 with a 90Hz display gets better battery life than the 120Hz OnePlus 8 Pro with its larger 4,510mAh battery? The two phones have otherwise virtually identical specs, highlighting just how much of an effect displays and refresh rates have on battery life.

Battery life isn’t just a hardware consideration either. Smartphone software can also affect battery life by killing off background apps to reduce CPU usage and wake-ups. For example, Huawei’s EMUI is notoriously more aggressive in this regard than Samsung’s One UI.

5G is power intensive

Another recent trend complicating the matter of mAh vs battery life is the launch of 5G. 5G modems and radio components require more power than previous-generation 4G equivalents, meaning that your battery won’t go as far if you’re on a 5G network. Complicating things further, different 5G modems and chipsets drain different levels of power.

Mid-range chipsets with integrated 5G modems, such as the Exynos 980 and Snapdragon 765G, should consume slightly less power than the premium tier external modems used in flagship smartphones. This may be partially why phones like the LG Velvet and reportedly even the Google Pixel 5 are set to ditch Qualcomm’s power-hungry flagship tier chipset, the Snapdragon 865. Again though, these SoCs have slower peak speeds, so it’s another power versus performance trade-off.

The move to 5G hardware has undoubtedly increased the necessity for larger battery capacities. However, whether this is a crucial purchasing consideration depends on whether you’re actually on a 5G or 4G network. If you’re sticking with a 4G tariff for now, then power consumption from these components won’t be as high, and battery life should be more in line with previous generations. Again though, this all depends on other hardware. According to Redmi general manager Lu Weibing, the move from 4G to 5G typically consumes at least 20% more power. So you’ll need a roughly 20% larger battery capacity to achieve the same battery life as an equivalent 4G phone.

Looking out for the best battery life

Oliver Cragg / Android Authority

The key takeaway from all of this is that building a smartphone with all-day battery life isn’t as simple as picking the biggest battery possible. Manufacturers have to weigh up cost, space, and the hardware they intend to power. The more feature-rich a handset, the tricker the balancing act. Most manufacturers try to target a balance of hardware and battery capacity that will get you through a full day of typical use, and sometimes that doesn’t require a huge cell.

Our stress test doesn’t identify a direct correlation between capacity and battery life because there isn’t one. Bigger batteries obviously provide more power to play with, but manufacturers’ underlying hardware choices have just as big of an impact on actual battery life results.

There are far more pieces to the battery life puzzle than just pure capacity.

Mid-range smartphones with less energy-hungry technology, such as the Pixel 3a, tend to get away with smaller batteries while still providing all-day battery life. In the premium segment, manufacturers use larger battery capacities (and the phones are bigger too) to power more demanding technologies, like 5G, high refresh rate displays, or extra gaming performance.

Of course, how you use your phone adds a whole other layer to the battery life debate. Casual Facebook browsers are bound to end up with much more battery left at the end of the day than mobile gamers.

Best phone battery life 2023: The longest-lasting smartphones ranked — Save on power banks during the Amazon Spring Sale

We put every smartphone to the test to find out which has the longest-lasting and best phone battery life in 2023

Deciding on which smartphone to buy is no easy task. We all need a phone with top-notch performance and a capable camera for our Instagram snaps, but a smartphone’s battery life is an increasingly important factor. No matter how excellent your brand-new phone is, it’s not much use to anyone if you’re always having to charge it.

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When making your decision, it’s best to look at battery size (measured in mAh) to give you an indication of how long-lasting the phone should be. But other factors such as display size and resolution and power efficiency still play a massive part, too. But there’s no need to simply guess – we’ve got you covered when it comes to the phones with the best battery life.

Every single phone that passes through our doors is faced with our in-house battery-life test. As such, we know exactly which phones you need to consider if battery life is at the top of your agenda. Below, we’ve ranked the top 20 best phone battery lives of 2023, including those pricey flagships and forgotten-about budget alternatives.

Best phone battery life 2023: How we test

To find out how well your phone performs against its rivals, we’ve combined all the battery scores from the countless smartphone tests we conduct every year into one easy-to-use graph, so you can see which phones are the best battery performers.

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To measure a smartphone’s battery life, we run a continuous video-playback test. The video file includes a handful of scenes from Spider-Man 2, encoded to H.264 and looped to a 20-hour length. We use the VLC video player app on either Google Play or the Apple App Store to play the file and record the length of time played on reboot. We also set the phone to aeroplane mode, turn off any automatic brightness and sleep settings, and set the screen brightness to a standardised 170cd/m2.

Aeroplane mode switches off all of the phone’s wireless features – naturally, extending battery life – which means that our tests are repeatable and consistent. The big problem with wireless is that signal strength can come and go, which forces the phone to adjust the amount of power that it uses constantly, causing variable results.

Best phone battery life 2023: Results

As you can see from the graph below, smartphone battery life, despite stagnating a little in recent years, has rapidly improved. All 20 phones in our hierarchy reached well over 23 hours in our battery benchmark before needing to recharge, and a significant chunk of the most recent headsets (which make up a lot of the list) seriously outdo their predecessors as well.

That includes the Samsung Galaxy M31, which pushed the previous winner, the Lenovo P2, from the top of the podium. Lasting over 30 hours in our battery test, the Galaxy M31 beat the Lenovo P2 by more than 90 minutes under the same conditions, making it the first phone we could recommend with a proper two-day battery life, and then some.

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This is the benchmark for all upcoming smartphones to aspire to. In second place, we have the Sony Xperia 10 IV, which just about edged in front of its predecessor (now in third), coming in at 29hrs 36mins. The Realme 9 4G makes its first appearance in fourth place, too, lasting for 28hrs 17mins.

OnePlus absolutely dominates the top 20 list, with a total of six phones (and even more narrowly missing out). Realme, Samsung and Motorola follow behind with three handsets each.

Best phone battery life 2023: iPhone results

As I mentioned earlier, only one iPhone manages to make an appearance in our overall battery life chart, so I’ve decided to make a separate section for fans of Apple who might be curious to find out which iPhone reaches the top of the iOS podium.

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Historically speaking, few iPhones have managed to compete with the likes of Android, but things have dramatically improved since the launch of the iPhone 11. As the below chart proves, every single new iPhone 14 squeezed out enough juice to last over 20 hours, with only last year’s iPhone SE (2022) failing to make the cut. The iPhone 14 Pro Max, iPhone 14 Pro, iPhone 14 Plus and regular iPhone 14 narrowly miss out on appearing on our top 20 list above.

I’ve ordered this graph in a slightly different way, instead listing them in release order. As you can see, despite a few stumbles along the way, iPhone battery life is generally improving (aside from the mini and SE versions). Note: we began our standardised battery testing in 2013, so there isn’t any data before the iPhone 5C, and neither is there any data for the iPhone 7 Plus, because our battery test failed to run.