65, 100 and up to 120 W. New advances in fast charging technology are creating serious doubts about the safety of this type of system. Today, most technologies allow a full charge to be achieved in an average time of 30 minutes or 1 hour maximum. The arrival of new standards, such as Qualcomm’s Quick Charge 5.0, promise to reduce these figures to 15 minutes. Yes, you read it right. 15 minutes. The problem is that this type of system can compromise the useful life of the batteries, or so the gossips say. How true is all this? Is fast mobile phone charging safe? Let’s see what science says.
Is fast charging bad for mobile phone batteries?
The short answer is yes. To understand the impact that fast charging has on batteries we have to know the inner workings of a battery.
What happens inside a battery when connecting a charger to charge your cells is a continuous movement of lithium ions between the negative electrode and the positive electrode. In this way, the cells obtain the necessary charge to supply power to the rest of the phone’s components.
When we use fast charging, this process is accelerated even more, by introducing a higher amperage, something that in itself is not harmful to the battery components. What reduces the useful life is the interaction between particles when traveling between the positive electrode and the negative electrode. This was confirmed by a study carried out by Purdue University, a study that we can view through this link on the official website of the University.
The study in question tries to explain the impact of fast charging on electric cars, laptops and smartphones. Despite being written in English, those responsible released a video that explained the operation of a battery at a “particular” level in a somewhat more graphic way through X-rays.
Just below this paragraph we can see the ‘degree of damage’ that the particles have suffered over time after undergoing rapid charges. The red areas correspond to the most affected particles, while the green areas show an optimal state of health.
The conclusion mentioned in one of the original research theses is as follows:
“When the batteries are recharged, the lithium ions that make up the cells make a back-to-front movement between the two electrodes, the negative and the positive. By interacting with the particles in the electrodes, they break and degrade more quickly.
This wear is even more pronounced when the mobile is connected using fast charge. ”
In addition to the Purdue University study, there are several investigations that help confirm that fast charging is bad for long-term batteries. This other study from the Idaho National Laboratory that we can download in PDF format demonstrates the impact of fast charging on electric cars, specifically in several Nissan Leaf of the year 2012.
Testing of the study was conducted with four identical Nissan Leaf models. Each of these vehicles were classified into two groups. While two of the cars were charged daily with a fast charge charger, the other two remaining cars were loaded at a speed considered “normal”. Neither too low nor too fast. The result?
After the first 50,000 American miles (around 80,000 kilometers to change), the first group had suffered a 7 kW degradation over the total capacity of the batteries. The second group, meanwhile, had lost just over 5 kW. This is reflected in the image that the study itself attaches and that we can see just below this paragraph.
That is to say that the study has been carried out with batteries whose capacity is far from what we can find in current mobile phones. Following the logic of the investigation, this degradation could be much more drastic in smaller modules. To this we must add that the stress suffered by the batteries is much higher if we talk about 100 or even 120 W.
Possible solutions to battery degradation problems
The future of the automotive industry and electronic devices in general (laptops, mobiles, tablets …) is marked by the advancement of batteries. Manufacturers know this and therefore create systems that help reduce the impact of this type of load.
OnePlus, for example, has designed a charger that helps minimize this degradation, at least in theory. As a general rule, the impact of fast charging is absorbed and expelled by the phone and battery as heat. For about a couple of years, the company includes a charger that absorbs all that heat to maintain charging speed.
Another solution designed by Oppo has to do with the use of two batteries, a system that Apple has been replicating in some of its high-end models. When charging a device with two batteries connected in parallel, the phone is charged through two completely independent cells. In this way, the impact is divided between two components to reduce its long-term consequences.
The last of the solutions is related to a change in battery composition. Currently, the two most widely used battery types in mobile telephony are Li-Ion (lithium ion) and LiPo (lithium polymeters). The next big step will come with graphene batteries, a material that promises to store a greater amount of energy in the same size as a conventional battery while providing greater resistance to the passage of time.
At the moment, it is not known when it will come to fruition. What is a fact is that a multitude of companies are researching this material to present a battery that outperforms lithium batteries once and for all.