It doesn’t matter what smartphone you have, how old it is, or how much it cost, one phenomenon that you are going to experience is charge running down even when the screen is dark and the phone is not in use. Only when a smartphone is turned off will it hold its charge (although, even then, it does lose charge incrementally).

This is nothing to do with the quality of the battery either. In fact, the batteries powering smartphones have undergone incredibly rapid development in recent years, making use of the same technology that has made myriad other “smart” technologies – such as the USB C rechargeable Li-ion batteries produced by tech start-up Pale Blue Earth – possible. Smartphone batteries are now more powerful, can charge quicker, have more advanced “smart” interfaces, and can last much longer but they will still be run down even when the phone is not in use.

Why Does This Happen?

So, why does this happen? Why does a phone lose charge even when it is not in use? The first thing to note is that this is a phenomenon shared by all batteries, of any kind. Holding charge is not the same thing as a box holding an object, or a vessel holding some liquid. Electricity stored as chemical energy is a volatile substance (in other words, it wants to escape) and it will always find ways of doing so, however slowly this might be. This is known as battery degradation, and it applies to even the most advanced of batteries. For example, a top lithium-ion battery will lose twenty percent of its charge after a year of storage.

But of course, this phenomenon does not really answer the question. The timescales involved in battery degradation are far too long to explain how your smartphone battery can run down in a few days when the phone is not in use. To explain how this happens, we need to discuss several reasons, not just one.

Reasons for Smartphone Battery Depletion

Here follows some of the main reasons why your smartphone runs down when you are not using it:

Background Apps

When you open an app on your phone, it doesn’t close again after you exit it. In fact, for many varied reasons it will most likely keep running. Your phone is simply doing a lot of things even when the screen is dark. For example, wi-fi will still be running, GPS is constantly in action, and your phone is still receiving messages and emails. It is simple enough really: your phone is doing work when it’s not in use, and this runs the battery down.

Bad Network Reception

Sometimes, your phone can also run down when it is not doing something – specifically receiving an inadequate network reception. Therefore, when you’re travelling through areas with a bad network reception, your phone is boosting its transmission power as much as possible, which drains the battery.

Battery Composition and Quality

Although all phones will lose power even when not in use, some batteries suffer from this problem more than others. If it is happening excessively, then it’s likely that your phone is suffering from a sub-standard battery. Even if your phone has an li-ion battery, the quality and relative purity of the materials has an effect. Cutting any corners here is sure to run the battery down quicker.

So, there you have it. There are many reasons why a phone’s battery runs down even when not in use. The only thing that you can know for certain is that, for now, it is an inevitable problem.