We put every smartphone to the test to find out which has the longest-lasting and best phone battery life in 2021

　　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.

　　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 2021, including those pricey flagships and forgotten-about budget alternatives.

　　Best phone battery life 2021: 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.

　　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 2021: 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 over 22 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.

　　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 can recommend with a proper two-day battery life, and then some.

　　This is the new benchmark for all upcoming smartphones to aspire to. In second place, we have the Sony Xperia 10 III, which smashed past its predecessor's stamina, coming in at just under 29 minutes. The Moto G9 Power is next on the list, which has a massive 6,000mAh battery and achieved a score of 28hrs 50mins.

　　Both Samsung and Motorola are dominating the top 20 list with six handsets each, including new additions such as the Galaxy S21 and Moto G50. Google and OnePlus are the second most prevalent, with a joint three handsets a piece. As you might have spotted, Apple fails to make the cut, although its battery life is doing better than in recent years – I've added a separate iPhone section at the bottom of this article.

　　5G phones now outnumber the amount of 4G handsets for the first time, too. With a total of 12 5G-capable smartphones making the cut, this list includes the aforementioned Xperia 10 III and Galaxy S21, as well as the OnePlus 8T, OnePlus Nord CE, Asus ROG Phone 5 and Google Pixel 4a 5G.

　　This list does come with a caveat, however, as you can't expect similar levels of stamina as soon as you switch on data connections – 5G is quite a power hog according to our real-world testing.

　　best battery time phone 2021: iPhone results

　　As I mentioned earlier, not a single 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 podium.

　　Historically speaking, not a single iPhone has 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, the longest-lasting is last year's top-end handset, the iPhone 11 Pro Max, which reached a total of 20hrs 7mins in our testing. That's a very good result, and while it might be just shy of our overall top 20 list, it's encouraging news for the future of iPhone, even if the iPhone SE (2020) scored quite poorly and the new iPhone 12 series doesn't quite reach the same levels of stamina.

　　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 iPhone SE and its small battery). 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.