Fast charging can damage the battery of my smartphone

The biggest battery myths and how to charge your cell phone battery correctly

Table of Contents

Let the cell phone battery become completely empty?

In the meantime, only the lithium-ion battery (Li-Ion) is used in smartphones. If possible, these should not be completely discharged to zero percent before charging. The reason: The electrodes of a lithium-ion battery are heavily loaded when fully charged up to 100 percent and when discharged until they are switched off. As a result, the life of the smartphone battery is significantly reduced.

When should the smartphone battery be charged?

Battery experts are of the opinion that the cell phone battery should be kept between 30 and 80 percent charge. This means that you get a greater number of charging cycles. As a result, it is best to feed the energy carrier with electricity only in this area. In addition, you should refrain from hanging the smartphone battery on the charging cable for a short time when it is low and recharging it at almost full capacity.

At night: properly charge the cell phone battery

Many users charge their mobile phones overnight, as the device is usually not needed during the night and morning hours. But what actually happens when the lithium-ion battery is full and the cell phone remains connected to the charging cable? After the energy storage device has reached its full capacity, a trickle current is either supplied until the battery capacity falls below the nominal value, from which the charging electronics start charging again, or the charging process is interrupted and only continued again when the charge falls below a certain value .

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Both cases use the battery. Above all, the discharge of a few percent in the heavily loaded last third of the charging process affects the energy storage device. To save the cell phone battery, it is therefore advisable to remove the cell phone from the charging cable as soon as it is charged. Experts are of the opinion that this should already be the case at a charge level of 90 percent. In addition, you save on the electricity bill, because charging cables also consume energy when a mobile phone is not connected.

Intelligent charging cycles, such as those used by Sony as a “battery care” feature in its smartphones, can remedy this: The cell phone battery is only charged to a certain harmless level overnight and then, depending on the use of the cell phone, only shortly before the alarm clock rings fully charged.

Can the smartphone battery be trained?

One hears again and again that a battery that no longer has a long runtime should be fully charged and then discharged several times so that it returns to its full performance. However, this “trick” does not work with modern lithium-ion batteries. The so-called conditioning of the energy store only plays a role with nickel-cadmium batteries. It may even have a negative effect on lithium-ion batteries. However, this does not increase the service life in any way.

It is possible that a new smartphone does not reliably display the battery level in the first few days of use. This is because the interaction between the battery, charging electronics and software is not yet working properly. After a short time, however, the system has collected so much information that the battery status is displayed correctly. So the battery indicator is better, not the lithium-ion battery.

The memory effect

The aforementioned conditioning of a battery primarily affects nickel-cadmium and nickel-metal hydride batteries. However, both battery types are now extremely rarely used. With a few exceptions, nickel-cadmium batteries have even been banned since 2009.

However, if this energy storage device was charged before it was empty, it “memorized” the time and level and would no longer use its full capacity in further charging cycles. With lithium-ion batteries, this process, known as the memory effect, is a thing of the past.

Charging electronics vs. deep discharge

Lithium-ion batteries are therefore not affected by the memory effect. However, so-called deep discharge can occur with this type of battery. This can happen if you take so much power from the battery that the capacity is completely exhausted. The voltage drops below the end-of-discharge voltage and the battery is permanently damaged. In the worst case, this can lead to a short circuit.

But: Almost all batteries that can be found in current smartphones and tablets have charging electronics. This should protect the battery from a short circuit, overheating or overcharging and load as little as possible with an optimal charging current. The device simply goes out even though the battery still has reserves.

Battery care and storage

If you use an exchangeable battery, it is advisable to store the unused battery in a cool and dry place such as the cellar. This extends the battery life. The aging process, which gradually reduces performance, is the slowest here. However, the ambient temperature should not be below 0 ° C. Here the performance also drops, which is particularly important in winter. Storage in the refrigerator is rather questionable because the humidity is too high.

When storing, the cell phone battery should be about half charged; experts recommend a charge level between 40 and 50 percent. The battery gradually loses its charge even in this environment, so it should be recharged from time to time to avoid the risk of deep discharge.

Cell phone batteries: fast charging and USB Type-C

Many manufacturers such as Samsung, Xiaomi or Oppo offer quick charging functions in their devices and advertise with phenomenal charging times. In some cases, the information is exaggerated, but now many devices can manage half a charging capacity in less than 30 minutes, and the latest technology can even do more. It should be noted that the speed of the charging process depends on how much energy is already available in the battery. Rough rule: the fuller the smartphone battery, the slower it charges. In addition, the possible capacity of the battery - measured in milliampere hours (mAh) - naturally plays a role in the charging speed.

Charge the cell phone battery faster: Increase the charging speed

The charging time can be quite long, especially with smartphones that do not have a quick charge function or if the energy source from which the cell phone battery is charged is quite weak (for example a USB port on the notebook). Normally, this shouldn't be a problem if the smartphone is charged overnight. However, if it has to be as quick as possible, the following applies: Charge the cell phone battery correctly.

→ Charging a mobile phone: Almost everyone makes this fatal mistake

This time, however, this does not refer to battery care, but to consumption, because all devices that run on electricity have. The cell phone is charged on the one hand, while the cell phone battery consumes energy and discharges itself on the other. Even when the display is switched off, numerous processes that require electricity run in the background. So that the energy store fills up faster, it must be switched off beforehand. Specifically, it is advisable to activate the (extreme) energy-saving mode or even the airplane mode. However, it is even better to switch off the smartphone completely and only start it up again when necessary. In this way, the loading time can be reduced to a minimum.

Charge smartphone battery wirelessly

For several years now, smartphone users have had the option of charging their devices wirelessly. The mobile phone is placed on a special charging station and the battery is "filled" using induction. The big advantage is that there is no mess of cables. Instead of waving a micro USB cable at the plug contacts, the charging process begins after the smartphone is put down. In addition to this advantage, however, the new technology also has some major disadvantages.

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The efficiency of the inductive charging station is lower than that of normal cables. This means that part of the energy is "consumed" without reaching the lithium-ion battery. Furthermore, wireless charging extends the charging time, as most inductive stations only have a low electrical current (amps or A) compared to wired fast charging technologies.


This happens in the cell phone battery if it is incorrectly charged

In order to be able to charge the cell phone battery correctly, a basic knowledge of batteries is recommended. A lithium-ion battery generally consists of electrolyte, two electrodes, each positively and negatively charged, and the lithium-ion. The battery already loses capacity in a natural way, a normal aging process for batteries. Since lithium and electrolyte react with each other inside the battery, the lithium ions decompose - the battery capacity is reduced. If the battery is charged incorrectly, for example if it is permanently and fully charged and discharged, this aging process accelerates. If the cell phone stays on all night, the battery is under voltage for far too long - this puts a strain on the electrodes and the lithium ions in the battery.

The aging of lithium-ion batteries is mainly caused by the oxidation of the electrodes. You lose the ability to store the lithium ions that are important for the flow of electricity. The main reasons for increased cell oxidation are the current temperature and the charge level of the battery. Cell oxidation is particularly rapid at high temperatures and with a fully charged battery.

Top 12 tips in summary

  1. Do not fully discharge and charge cell phone batteries (not below 10 / above 90 percent)
  2. It is best to keep smartphone batteries at a charge level between 30 and 80 percent
  3. Do not charge overnight
  4. There is no memory effect with lithium-ion batteries
  5. Beware of deep discharge
  6. Charge your mobile phone correctly: switch off the device to fill the percentage display quickly
  7. If the device is not used for a longer period of time: remove the battery from the device
  8. Ensure battery storage in a suitable environment (ideal: cool, dry cellar)
  9. Do not store the cell phone battery fully charged or almost discharged
  10. Do not charge or operate the mobile phone battery permanently in a cold environment (below 10 ° C)
  11. Likewise, do not charge and operate permanently in a hot environment (over 35 ° C)
  12. Do not use inferior cell phone batteries or chargers
Battery life: With these 10 tips, your smartphone will last longer