How to keep your phone battery healthy
Discover how to prolong the life of your mobile battery and stop it losing charge as well as what to do if it’s on the way out
Surprisingly, the shortest-lived component in a modern smartphone isn’t the screen, on-off button or the USB port – it’s the battery – and since most phones don’t have user-removable ones, this is the most likely one to fail.
However, you can prolong the useful life of your phone by maintaining its battery “health”. This means that your phone’s battery will keep most of its capacity for longer, and you won’t have to replace your mobile as soon as you would otherwise. Some of the best smartphones will last over a day on a single charge; this will drop off as your phone ages, however there are steps you can take to delay the inevitable.
What is phone battery health?
This is a measure of how well your phone battery is able to top up and hold a charge. A battery with good or optimum health can charge to a high capacity and hold its charge for a long time, whereas one with poor health can’t hold much of a charge and runs out quickly. Certain factors like temperature, usage patterns and how often (and how) you charge your phone have an impact on this, but we’ll come to those below.
Current smartphones use lithium-ion battery technology. These have the highest energy density compared to other battery technologies, and can charge relatively quickly. However, they have a limited number of full charge cycles before the total capacity starts falling. It’s normal for a phone to have only 80% of its original capacity left after a few years of use.
Your usage patterns can speed up this degradation, and of course, if you’re putting the battery through several full charge cycles per day then that capacity will drop more quickly compared to someone who’s only charging their phone once a day overnight.
How to check your battery health
There are two main types of mobile on the market – Android and iOS (Apple). The way to check current battery health on either platform varies, so let’s have a quick look at them in turn.
How to check battery health on an iPhone
Head to Settings > General > Battery > Battery Health & Charging. 
Here you’ll see what battery capacity remains. In this case, our iPhone 13 Pro has 87% of its battery capacity left, which is still acceptable, and it probably has a few years left before this starts dipping below 80% and you start running into problems.
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How to check battery health on an Android phone
Android phones are a little tricker, since the available features can differ from one model to the next – which is why you should do an internet search for “battery health” and your specific model.
For example, on my Samsung Galaxy S22 Ultra, this function isn’t even in the Android system menus. Instead, you need to open the Samsung “Members” app and find it under Support > Phone diagnostics > Battery.
If you don’t have any way to check battery health on your Android handset, you can always search the Google Play Store for a battery health app, though some will only be compatible with certain handsets or Android versions.
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Symptoms of battery health decline
If you don’t have the option to check battery health using an app or system-level function, then you can diagnose it by external symptoms such as:
- Fast battery drain.
- Charging takes far longer than usual.
- Strange jumps in battery percentage.
- Overheating while charging.
The most severe indication that a phone battery is on its last legs is “swelling” – this is when your battery expands and distorts the shape of your mobile. It’s a dangerous state of affairs that could result in your mobile catching fire or even worse, exploding. At the first sign of this you should turn your phone off and take it to a professional repair shop as soon as possible.
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How to maintain battery health
If your phone’s battery health is still in the green, here are some things you can do to stay there for longer.
Avoid temperature extremes. Lithium batteries should always be within their optimal operating temperature. Extreme heat and cold are both bad for the lifespan of your battery.
Use the optimised charging functionality if your phone has it. On iPhones you’ll find the settings under “Battery Health & Charging”. On Android phones, the location varies, but it’s known as “Adaptive Charging” (AC) on the Pixel 7a. When you enable this feature, AC takes about 14 days to learn your charging habits to prolong battery health. For example, if you regularly plug your phone in to charge overnight, the AC feature may only turn on to charge the battery to 100% one hour before you unplug.
Both iPhone and Android devices offer a record of which apps use the most battery power under their battery settings. If an app is really hitting your phone’s battery hard, you could uninstall it or limit its background activity.
Turn your screen brightness down. The screen is often a phone’s most power-hungry component.
Some phones, such as recent models of Galaxy Ultra phones from Samsung offer a “charge limiting” feature. In the case of my S22 Ultra the limit is 85%, and this is a good way to reduce battery wear if available on your handset.
Do an audit of which of your apps can activate location services in the background and restrict this access for those apps you have little need of. Having your GPS constantly activated will increase heat and battery drain.
If you don’t have automatic optimised charging on your phone, you can manually make sure that you charge it before it gets below 20% and stop charging it when it hits 80-90%.
These measures will likely keep your battery healthier for longer. However, if you need your phone to be charged to 100% on a trip, for example, just do it. You only need to follow these guidelines most of the time for them to be effective.
Get the battery replaced
Although modern smartphones are sealed and have their batteries glued in, that doesn’t mean they are impossible to replace. You can usually get a professional battery replacement for most modern mobiles. Some Android phones such as the Nokia G22, which we gave four stars in our review, are designed so you can replace components like the battery and screen yourself with relative ease. Just follow iFixit tutorials using official replacement parts and repair kits.
Otherwise, Apple will replace your battery for a fee. At the time of writing, your nearest Apple store (or Authorised Service Provider) will charge £85 for a new iPhone 13 battery. This is an official installation with an original battery, and will add years to your phone’s lifespan if it’s otherwise defect-free. As for Android phones, getting a professional third-party battery replacement for a Galaxy S22 Ultra costs roughly the same, using an original Samsung battery.
So if your phone’s battery health really is beyond the point of return, don’t be afraid to get a quote for a professional replacement – your first port of call should be your mobile maker’s website – it’s far less expensive than buying a whole new phone if you don’t need one.
Don’t forget, if your battery health has dropped below an acceptable limit within its warranty, you’ll most likely qualify for a free replacement.
If you’re in the market for a new phone after all, then you’ll want to look at our rankings for the longest-lasting smartphones with the best battery life.