Can non original chargers be used for charging and is it safe?
Article Source:Institute of Physics, Chinese Academy of Sciences | Author:Editor: Sheri | Issuing Time:2024.03.26
With the development of technology, we pursue a more efficient and convenient life. The electronic devices used in daily life are constantly being updated and replaced. In addition to greatly improving performance, the capacity and charging speed of batteries have also been significantly improved. The power of the charger is very different from what we purchased a few years ago. If we forget to bring the charger when we go home during holidays, can we use the old charger to charge our new phones? Or can a new charger be used to charge an old phone?
To find the answer to this question, let's first take a look at which components a battery charger is composed of!
CHARGER
The charger mainly consists of four parts: transformer, rectifier, filter, and regulator:
The transformer is the core component of the charger, consisting of an input coil, an output coil, and an iron core. Its working principle is to use electromagnetic induction to reduce the household AC voltage (AC) to a level more suitable for mobile phone charging during the charging process.
A rectifier consists of four diodes and is typically designed as a diode bridge rectifier. Its function is to convert the alternating current output by the transformer into pulsed direct current (DC).
Filters are usually composed of capacitors, used to smooth the rectified pulse DC current, remove fluctuations and noise in the current, and make the output more stable.
A voltage regulator is usually implemented by an integrated circuit, which can automatically adjust the power output, maintain the stability of the output voltage, and ensure that the device can charge safely.
In addition, the charger may also include a control chip responsible for managing and regulating the entire charging process; Status indicator light displaying charging status; Supporting resistors, capacitors, and inductors for circuit stability and filtering; And protective devices. The design of chargers may vary depending on the manufacturer and technical level, but their main functions and components are roughly the same.
Control chip
The control chip of the charger is the core component in the whole charging process. When the device is connected to the charger, the control chip will automatically identify the charging protocol and demand of the device, and then adjust the output voltage and current to meet the charging demand of the device.
It continuously monitors the battery voltage during constant current charging. When the battery voltage reaches the set constant voltage charging threshold, the control chip will switch from constant current mode to constant voltage mode to ensure that the battery will not overcharge.
When the battery is deeply discharged, the protective integrated circuit (IC) inside the battery may disconnect the battery connection. At this point, the control chip of the charger will provide a small current (such as 50mA) to charge the capacitor of the battery pack, triggering the protection IC to reconnect the battery. If the battery fails to reconnect within a certain period of time, the control chip will stop charging to prevent damage to the battery.
When the battery is reconnected or in a discharged state, the control chip will enter the pre charging stage. At this stage, the control chip safely charges the battery at a lower current level, causing the battery voltage to slowly rise.
Some charger ICs can also provide a stable output voltage for the working power supply, such as+3.3V, which can ensure the stable operation of devices such as microcontrollers.
To prevent overheating, control chips are usually equipped with thermal adjustment circuits. This can ensure that during the charging process, if the temperature is too high, the charger will automatically reduce the charging current or stop charging to protect the battery and hardware.
Modern charger control chips may also integrate other functions, such as reverse protection, short circuit protection, etc., to improve the safety of the charging process.
With the development of technology, some control chips also support fast charging function, which requires complex algorithms and efficient power conversion design to achieve fast charging while maintaining device safety.
Can high-power chargers charge appliances with lower power requirements?
The power labeled on the charger usually refers to its maximum output power, and the maximum output power of the charger refers to the upper limit of the maximum power it can provide. If the charger is labeled as 5V-2A, its maximum power is 10W.
If the design of the appliance itself does not support such high power, the charger will not forcibly supply power beyond its capacity. Therefore, high-power chargers can theoretically charge appliances with lower power requirements. A high-power charger is technically backward compatible, providing safe charging for low-power devices.
Attention:
1.When using non original chargers, we should ensure that they come from reputable manufacturers and comply with relevant safety standards. Chargers with miscellaneous or three no products may not guarantee stable output, causing damage to the equipment.
2. Some devices may have specific requirements for chargers, such as only using original or designated brand chargers. Therefore, before using a non original charger, it is best to check the device manual or consult the manufacturer to ensure compatibility and safety.
What if a lower power charger is used to charge appliances with higher power requirements?
This may result in inability to charge or extremely slow charging speed.
When we cannot charge with an incompatible charger, it may be because different models of electrical equipment have differences in circuit design; In addition, although many devices use the same interface, they may support different charging protocols, which may also result in inability to charge.
Have you noticed that the charging speed of mobile phones is changing?
The design of charging speed is a complex process that involves not only the chemical reactions and material structure inside the battery, but also the control and optimization of external circuits.
From a physical perspective, charging speed is related to power, which is the product of current and voltage. This means that theoretically, the charging speed can be improved by increasing the current or voltage. However, the charging process of lithium batteries is not a simple power input, and we need to consider the health and safety of the battery.
During the charging process of lithium batteries, lithium ions are released from the positive electrode material, moved to the negative electrode through the electrolyte, and embedded into the layered structure of the negative electrode.
During rapid charging, more heat is generated inside the battery, leading to an increase in battery temperature and accelerating battery aging. In addition, the impact of charging and discharging speed on battery life is also reflected in physical changes in the internal structure of the battery, increased internal resistance and polarization, lack of positive and negative active substances, and lithium deficiency. The higher the charging and discharging rate, i.e. the faster the charging speed, the faster the decay rate of the battery also increases.
To protect the battery and ensure safety and efficiency during the charging process, the charging of lithium batteries is usually divided into three stages:
Constant current pre charging stage: This is to prevent the battery from being damaged when the battery level is too low. At this stage, the battery is charged at a lower current until the battery voltage reaches a safe level.
High current constant current charging stage: Once the battery voltage reaches a predetermined level, the charging current will increase, and the battery will be charged at the maximum allowable current until the battery voltage approaches its rated voltage.
Constant voltage charging stage: During this stage, the battery voltage is maintained at a fixed level, and as the battery gradually fills up, the charging current gradually decreases until the charging is completed.
The development of fast charging technology is also the key to improving charging speed. Fast charging technology achieves fast charging by optimizing battery design and using special charging protocols. For example, some chargers support the Qualcomm QC2.0 protocol, which can reduce the voltage to 12V/9V/5V to meet the charging needs of mobile phones.
In order to achieve fast and safe charging, battery manufacturers should strive to increase energy density to increase battery capacity, while chip manufacturers seek low-power solutions to improve charging efficiency, which will result in a one plus one greater than two effect.
Many times, for convenience, we choose to charge our mobile devices overnight. This has indeed brought us convenience, but is it really good for the battery?
The optimal range for battery life is between 20% -80%, which can slow down the rate of battery aging. During the charging and discharging process, overcharging affects the lattice structure of the positive electrode material, while over discharging affects the structure of the negative electrode material. Especially in the case of complete discharge, it may cause the negative electrode material structure to collapse, which is permanent and can lead to a decrease in battery capacity.
Temperature is an important factor affecting the internal chemical reactions of batteries. When the battery is charged, the temperature usually rises, especially in fast charging mode. Continuing to charge the battery while fully charged may cause the battery temperature to remain high.
At high temperatures, electrochemical reactions become more active, the discharge capacity of the battery is enhanced, and the internal resistance is reduced. However, excessively high temperatures can exacerbate the side reactions between electrolytes and positive and negative electrode materials, leading to the consumption of electrolytes and active materials, thereby causing battery capacity degradation and internal resistance increase. Overdischarge may also cause dissolution of the negative current collector (such as copper foil).
The cycle of complete charging and complete discharging will cause significant losses to the battery, thereby shortening its lifespan. Under the same conditions, maintaining the battery capacity of lithium-ion batteries at around 50% is less damaging than maintaining the battery capacity below 20% or above 80%.
Therefore, in order to extend the service life of the battery, it is recommended to start charging when the battery level drops to 20% and try to avoid charging the battery to 100% for a long time. At the same time, using the original charger to charge, avoiding charging in high temperature environments, and stopping using the phone when the battery heats up are all good habits to protect the battery!
Reference materials
[1] Su Zhendong, Meng Qingguo, Yin Qian. A SOH estimation method for power lithium battery systems [J]. Science and Technology Innovation and Application, 2022, 12 (06): 155-157. DOI: 10.19981/j.CN23-1581/G3.2022.06.045
[2] Qing Xiaodong. Performance improvement technology for electric field coupled wireless energy transmission systems under coupling capacitance and load changes [D]. Chongqing University, 2021. DOI: 10.27670/d.cnki.gcqdu.2021.003736
[3] Ren Xiuying Research on Topology Improvement and Efficiency Enhancement of Bidirectional DC-DC Converter in UPS [D]. Harbin Institute of Technology, 2016
[4] Chen Dongpo. Research and design of high-efficiency, multi-mode, and multi output power management chips for portable electronic devices [D]. Zhejiang University, 2008
[5] Jing Bing, Lu Peng, Li Bo. Analysis of Factors Influencing Capacity Decay and Cycle Life of Lithium Battery [J]. China Security and Prevention Technology and Application, 2018, (03): 62-67
[6] Zhao Meinan Research on the Interaction and Energy Storage Characteristics between Metal Borohydride and Carbon Materials [D]. Anhui University of Technology, 2019