Which size of phone battery should I look for?

Everyone hates it when their phone runs out of battery before bedtime. So, if you’re in the market for a new mobile phone, which size of phone battery should you be seeking to ensure the phone doesn’t need a nap before you do? Here’s what to look for when it comes to phone batteries.

How is the size of phone batteries measured?

The size – or more accurately, the capacity – of phone batteries is normally expressed in milliamp hours or mAh. The Samsung Galaxy S22 has a 3,700 mAh battery, for example, whereas the iPhone 13 has a 3,240 mAh battery. Apple doesn’t disclose the capacity of iPhone batteries in the tech specs on its website, so you have to go the brilliant GSM Arena to get such information.

So, the bigger the battery the longer the phone lasts?

It’s not quite that simple. Factors such as the size and resolution of the screen, as well as the components used inside the phone, will have an impact on battery life. A phone with a 6.5in 4K display is going to burn through battery much more quickly than one with a 5in screen.

Likewise, phones with the powerful processors and graphics chips needed to play the latest games at smooth frame rates are going to sap the battery faster than one with slower internals that struggle to play Fortnite, for example.

So, you can’t rely purely on the size of the battery when it comes to working out how long it will last. That said, the bigger the battery, the more chance it has of getting through a day without you having to whack in the charger.

What phone battery capacity should I be looking for?

If you want a phone to have a strong chance of getting through the day without needing a charge, I’d be looking for a phone with at least a 4,500mAh battery. As you can see from the sizes listed above, that’s a higher capacity than you’ll find in both the regular iPhone 13 and the Galaxy S22.

There are some phones on the market with a 6,000mAh battery, but they are becoming increasingly rare. My two-year-old Samsung Galaxy M31 has a 6,000mAh battery and it can still get through two days without needing a charge, although newer models (the M32 and M33) have smaller batteries, which is baffling. That phone only cost £250.

The similar Motorola Moto G9 Power also has a 6,000mAh battery, but it’s now largely out of stock.

At the more expensive end of the market, the Asus ROG Phone 6 has a 6,000mAh battery, but that’s largely to support all of the powerful components inside that handset aimed at gamers. You’re looking at the thick end of £1,000 if you want that one.