When should you replace your mobile battery? The answer will surprise most people

At first, you only notice small changes, and where your phone previously lasted all day, you may now have to charge it in the late afternoon. Maybe the battery percentage suddenly drops even though you’ve barely touched the phone, or it turns off without warning even though it had 15-20% left.

Other obvious signs are that charging takes longer than before or that the phone gets uncomfortably warm while charging. The battery is under pressure and both battery life and performance may be affected.

You can quickly check the battery status in the menu. On iPhone, go to Settings → Battery → Battery → Battery status and charge, where you can see the maximum capacity of the battery as a percentage.

On Android, there is no single solution, but many Samsung phones display battery health in the diagnostic function in the Samsung Members app, and apps like Accubattery can give a good indication of capacity.

As a rule of thumb, a capacity of 80 percent or more is still considered healthy. If it drops lower, you’ll often experience significantly shorter battery life, even with regular use.

What does 80 percent mean and when is it really time?

A modern mobile battery can usually handle at least 500 full charges before it drops below 80%, with many newer models closer to 1,000 charges or more. For most, that’s at least a couple of years of use, often a little more.

When battery integrity drops below 80%, most manufacturers consider it worth considering a replacement. In practice, you can use the phone for longer than that, but if the capacity approaches 70 percent, both battery life and performance will typically be noticeably worse.

A review of smartphone failures, according to Which? that worn batteries are the most common cause of problems, while the battery itself is often the cheapest part to replace and an easy way to put off the next expensive phone purchase.

This makes battery replacement a more climate-friendly option than buying a brand new phone because you reduce the amount of electronic waste.

Before you decide, however, you should check how long the manufacturer will continue to provide security updates for your model. If support is due to expire within the next year, an actual upgrade may be the safest option.

What does a new battery cost and can you make small adjustments?

The cost of a battery change depends on both the model and the workshop. According to Which? an official battery replacement for the iPhone 12 costs around £85, while the iPhone 14 is around £95. This is roughly equivalent to £720 and £810 respectively at the current exchange rate.

Samsung Repair charges around £69 for a new battery for a Galaxy S22, which is close to £585, while Square Repair is around £80, or about £680.

Some manufacturers also sell loose batteries. One example is the OnePlus Nord 3 5G, where an original battery costs around £60, but you’ll have to do the installation yourself or pay extra for professional help.

Compared to a new phone, this is a low amount. You don’t need a top-of-the-range model for around 5,950 SEK to get a fast phone. There are recommended models from around £2,890 and good budget phones as low as £1,000.

Before you decide to change the battery, there are a few things you can do. Turn on power saving even before the battery hits 20 percent. Turn down the brightness, shorten the screen time and turn off the “Always On” screen if your phone has that feature.

Consider a power bank for long days and a fast charger that matches the wattage your phone actually supports to make the most of the minutes it’s plugged in.

Following these steps and keeping an eye on battery health percentages will give you a more accurate answer to when your phone needs a new battery.