Nowadays, the battery capacity of mobile phones is generally more than 2000-3000 mAh. Using a traditional 5V/1A charger, it takes at least three hours to fully charge a battery, which is much longer than the previous Nokia mobile phone, which took more than an hour to fully charge. With the improvement of battery capacity, the power of the original charger cannot meet the charging requirements, so the fast charging technology appears.
All major mobile phone manufacturers have launched their own fast charging technology, the principle of which is to increase the charging current and voltage to realize high-power charging. In simple terms, the input power of the charging port = input voltage x input current. Generally, mobile phone chargers will have a charging curve to achieve the highest charging efficiency by controlling different voltages and currents. Generally speaking, the most efficient way is to start with constant current charging (faster charging speed), then constant voltage charging (the charging speed drops because the voltage of the battery itself goes up), and finally trickle charging (after fully charged After that, the capacity loss due to self-discharge is compensated).
Most mobile phones now use Qualcomm QuickCharge charging technology. From the initial 1.0 standard to the latest 4.0 standard, the higher the standard, the higher the charging efficiency. QC1.0 breaks through the USB-IF agreement on USBBatteryCharge1.2, the voltage and current are increased to 5V2A, and the charging time is shortened by 40%. The real improvement of fast charging begins with QC2.0. Through the handshake protocol, the charger and the mobile phone recognize each other, and after the handshake, the transmission voltage is increased, up to 20V. Although the current remains the same, the charging efficiency has been improved by nearly 75%. On the basis of 2.0, QC3.0 introduces the optimal voltage intelligent protocol (INOV) algorithm to accurately control the charging voltage, and the input voltage reaches 200mV. In order to reduce the loss, at this time, with the controllable voltage, the current is increased to 3A. At present, the mainstream fast charging mobile phones use the QC2.0 and QC3.0 standards. When it comes to QC4.0, it is a finer intelligent adjustment of the control voltage. The accuracy has reached 20mV, and the charging current and voltage have become more flexible. There are constant 3A or non-constant 4.7A-5.6A, and the voltage does not need to reach 20V. Such a high, intelligent regulation between 5V-9V, finally has a speed increase of nearly 20%, and an efficiency increase of nearly 30%.
Fast charging technology requires more precise current and voltage control. The important reason is that it can obtain a more extreme charging curve. In the early stage of charging, high-power charging can allow users to obtain the maximum power in the shortest time. The remaining uncharged The battery capacity is to complete the charging by gradually slowing down to protect the battery and the circuit.
Mechanism of battery aging
Most of the batteries used in mobile phones are lithium-ion batteries. What we call battery aging refers to the attenuation and aging of lithium-ion batteries in daily use. Why does aging occur? Let me give you a popular science first about the working principle of lithium-ion batteries: lithium ions can travel through the electrolyte of the cathode and anode, thus generating a current that powers the device. The so-called battery capacity can be simply understood as the number of lithium ions running back and forth in the battery (during charging and discharging).
The materials that make up a battery's electrodes often crack and disintegrate, allowing certain metal ions (manganese ions in particular) to float freely and travel to the opposite electrode, where they trap lithium ions. When manganese ions (gray above) are stripped from the battery's cathode (blue field), they react with the electrolyte near the battery's anode (gold field) and trap lithium ions (green-yellow above). As time goes on, more and more lithium ions are not able to work properly (locked up), and the capacity of the battery is gradually reduced due to this, resulting in a decrease in battery life. Why is it aging?
1. Overcharge and overdischarge
There are many reasons for battery aging, the first is natural aging. Even with normal use, lithium ions will detach from the anode by themselves and gradually age, but the aging speed is slow; in daily use, overcharging and overdischarging of the battery will accelerate the aging of lithium-ion batteries. The current mobile phone usually has a rectification and voltage stabilization design. When the battery is fully charged, the charger power supply will disconnect the charging circuit and directly use the power cord to supply power to the mobile phone. If the original charger is not used, it is very likely that the power supply will not be cut off in time to continue charging the fully charged battery. It will accelerate the shedding of lithium ions, damage the battery, and cause battery aging; when the battery is exhausted, the freely moving ions will also be trapped, which also consumes the capacity of the battery.
2. The temperature is too high/low
In addition to overcharging and over-discharging, the battery temperature is too high or too low, which will also affect the battery life. Frequent discharge of the battery will generate heat, which will cause the battery temperature to be too high during actual use. Therefore, when we play large games or run other power-consuming programs, we should pay attention to heat dissipation and control the running time of programs. In the same case where the temperature is too low, the activity of lithium ions will decrease, and the battery performance and charging performance will also be greatly reduced. If the battery is charged forcibly, it will also affect the battery life. Therefore, in a severe cold environment, mobile phones, notebooks, drones and other devices must preheat the battery to reach a certain temperature before they can work normally.
3. The current is too high
In addition, the charging current will also affect the life of the battery. When the battery is charging, the current is too high, which will cause serious damage to the battery, and even cause short circuit, explosion, burning, etc. The original products of general manufacturers will have The charging protection circuit controls the excessive charging current of the battery, and in some counterfeit chargers and universal chargers, if the protection mechanism is not added, the consequences will be very serious. Will fast charging accelerate battery aging? the answer is no
As mentioned above, fast charging actually increases the power of the charger to increase the current and voltage, so if it is not adjusted, it will cause the battery to age. However, except for the oldest QC1.0 standard, the new version of the fast charging technology can only achieve a higher voltage fast charging mode through the handshake protocol. For some mobile phones that do not support fast charging technology, even if a fast charging charger is used, the charger will automatically reduce the charging efficiency to prevent accidents. After we understand the principle of fast charging, from a technical perspective, fast charging only increases the input voltage during charging. Generally, the maximum current of battery charging will be controlled within 6A, and QC4.0 maximizes the control of voltage and current. , but also in a safe range, there is no damage to the battery.
In general, the current fast charging technology of mobile phones will not accelerate the aging of batteries. On the contrary, the most fundamental reason for the accelerated aging of the battery is our bad charging habits. Bad charging habits that have to be understood
To talk about the bad habit of charging, it must be inseparable from the reasons for battery aging mentioned above. First of all, use the original charger and charging cable to prevent charging accidents caused by the poor quality of the charger. Problems such as unstable charging current are often caused by the quality of the equipment you use is not good enough.
Frequent charging will also easily accelerate the consumption of battery life, and even lead to reduced battery activity and shortened battery life. Especially after the addition of fast charging technology, although the charging speed is very fast in the early stage, the cable is unplugged before it is fully charged to 100%, resulting in multiple charging and increasing the number of battery cycles. Long-term use in this way will reduce the battery life. activity, thereby accelerating the aging of the battery. Just like pouring beer, the faster the pouring speed, the bigger the foam. A beer full of foam is not really a full cup, and the charging is the same. The slow charging in the second half of the fast charging is more important. So even if you use fast charging, try to make the phone fully charged before powering off.
In addition, the high temperature and low temperature of the battery will also cause great damage to the charging of the mobile phone. In the daily environment, charging while playing games often causes the temperature of the mobile phone to rise rapidly, and the high temperature environment accelerates the chemical reaction inside the battery, thereby accelerating battery aging. Therefore, it is hoped that the battery will be more durable, and it is best not to use it while charging. At the same time, in extreme environments, it is best to let the phone return to normal temperature before charging.