At a glance: How to charge a phone battery properly

• Memory effect is a myth, but modern rechargeable batteries still need to be looked after correctly
• Ideally keep the phone battery between 20 and 80 per cent
• The fewer charging cycles, the longer the rechargeable battery remains powerful
• If charged to 100 per cent: disconnect mobile phone from the charger

How to charge a phone battery properly: When, how often and for how long?

The often-feared memory effect is fortunately a thing of the past. Yet even modern lithium-ion or lithium-polymer rechargeable batteries lose performance over time if handled incorrectly. It primarily depends on when and for how long you charge your mobile phone.

Important: Precisely when you should charge your mobile phone depends on the intensity of use, i.e. at what percentage you charge the battery. For a long battery life, avoid completely draining the battery and end the charging process once the device is charged. However, permanently leaving the mobile phone connected to a charger offers no advantages. Depending on the capacity and charging speed, several hours can pass until charging is finished.

Model-dependent charging technologies protect the rechargeable battery as standard. For example, Apple uses machine learning to charge iPhone rechargeable batteries gently. You can find out how that works and what you should specifically bear in mind when charging iPhones in our guide The correct way to charge an iPhone.

Tip: It’s best to use modern rechargeable batteries within the range of 20 to 80 per cent. This means you should ideally connect your device when there is around a 20 per cent charge left and end the charging process once the rechargeable battery has reached around 80 per cent.

How often you should charge your mobile phone then depends on your use. The faster you have drained the rechargeable battery to 20 per cent, the more often you need to use a charger.

Would you like to use your mobile phone while it is charging? You can do that without any problems if you are writing messages and checking e-mails. However, you should avoid any power-hungry tasks during charging to minimise heat development. This means it’s best to start video chats, film or gaming sessions with a fully-charged battery without a charger being connected.

Charging a phone battery overnight

It can be good for the rechargeable battery cells if you charge the phone battery gently overnight. It primarily depends on the right charger for your smartphone model, as there are differences in the charging technology. Find out more about this in our article Charging a phone overnight.

Fast charging of mobile phones

The battery percentage climbs back into a comfortable range within just a few minutes. Charging a mobile phone more quickly is sometimes extremely handy in everyday life. However, are the various fast-charging functions from smartphone brands really gentle on the rechargeable battery or should you instead charge your mobile phone slowly? This depends on the brand and the fast-charge technology. In general, modern smartphones independently control the maximum voltage, so you can also charge the phone battery correctly with power supply units that seem too powerful.

Inductive charging: Charging without a cable

More and more smartphones support wireless charging. Instead of connecting a charging cable, you place such devices on compatible charging stations and the electricity flows into the rechargeable battery wirelessly. The Qi standard has become established for inductive charging. If your smartphone is Qi-compatible, you can use Qi charging stations to charge your phone battery correctly.

Tip: Allow a cold rechargeable battery to warm up slowly to room temperature again. Only then should you connect a charger and under no circumstances treat it with additional heat from the central heating or a hairdryer.

The normal temperature for a mobile phone is around room temperature. The device can also sometimes get warmer with intensive use. However, with normal charging, the mobile phone temperature should also remain within the normal range. Exceptions exist for fast charging. The charger can also get warmer, but increased temperatures are not normally a cause for concern in this case.

Original accessories: What you should bear in mind

Even if original accessories for charging are still supplied with devices nowadays, they often prove to be impractical in everyday life. If you want to charge up your phone battery correctly, you should have the best opportunities to do so in your personal daily schedule.

This is often only possible with clever accessories. As a result, when selecting accessories, pay attention to the connections and charging technologies that your smartphone supports. When it comes to charging speed, it simply depends on what voltage your mobile phone works with and with what maximum wattage you can charge up your mobile phone. Modern chargers are versatile and support many brands and models at the same time.

Charging your new rechargeable battery correctly

A new rechargeable battery already comes pre-charged. You don’t need to wait any longer after unpacking it and can use your new mobile phone straight away, without having to worry about causing damage to the rechargeable battery.

To make it last as long as possible, it is much more important that you charge a new phone battery correctly right from the start. Instead of charging the battery of your new phone straight away, take your time to set it up and familiarise yourself with it. If the battery percentage suddenly falls to 20 per cent, it’s time for the first charging process. If, however, you’re in no hurry to set it up, you can naturally charge your new mobile phone first, disconnect it from the charger at 100 per cent and then use it.