1. What is the most suitable current for lithium ion battery charging?
Lithium ion battery requires constant current charging first, namely must be current, and the battery voltage charging process gradually increases, when the battery voltage of 4.2 V, 4.1 V), constant voltage charging, instead of constant current charging for the voltage must be current depending on the degree of saturation batteries, as the charging process continue to gradually reduce, when reduced to 0.01 C, think charging termination. (C is a way of expressing the nominal capacity of the battery against the current, such as the capacity of the battery is 1000mAh, 1C is the charging current of 1000mA, note is mA rather than Ah, 0.01C is 10mA.) Why 0.01C is considered as the end of charging: this is stipulated in the national standard GB/T18287-2000 and also discussed. Before we generally end with 20mA, the ministry of Posts and Telecommunications industry standard YD/T998-1999 is also so stipulated, that is, no matter how big the battery capacity, stop current is 20mA. The 0.01C of the NATIONAL standard helps to charge more full, which is beneficial to the manufacturer through identification. In addition, the NATIONAL standard stipulates that the charging time does not exceed 8 hours, that is to say, even if it has not reached 0.01c, 8 hours to the end of the charge. (quality no problem of the battery, should be within 8 hours of 0.01 C, battery quality is bad, also meaningless wait) lithium ion or lithium polymer battery pack the best charging rate of 1 C, which means that a 1000 mAh battery have to be quick charge current of 1000 ma, charge at this rate can achieve the shortest charging time, It will not reduce the performance of the battery pack and shorten the service life. For the battery pack with increasing capacity, it is inevitable to increase the charging current value in order to achieve this satisfactory charging rate.
2. What is the most suitable voltage for lithium ion battery charging?
Lithium ion battery nominal voltage 3.7V (3.6V), charging cut-off voltage 4.2V (4.1V, according to the cell brand has different design) how to distinguish the battery is 4.1V or 4.2V: consumers are unable to distinguish, which depends on the cell manufacturer's product specifications. Some brands of cells are 4.1V and 4.2V general, such as A&TB (Toshiba), domestic manufacturers are 4.2V. What happens when you charge a 4.1V cell to 4.2V: It increases battery capacity, feels good, and lasts longer, but it shortensbattery life. Let's say we go from 500 to 300. Similarly, overcharging the 4.2V cell will also reduce the short life. Lithium-ion cells are delicate. Since the battery has a protection plate, can we rest assured: no, because the protection plate's cut-off parameter is 4.35V (this is still good, the difference is 4.4 to 4.5V), the protection plate is to cope with the case, if every time overcharge, the battery will soon decay.
3. What are apple's iPhone battery specs?
Apple iPhone battery specifications are nominal voltage 3.7V, charging cut-off voltage 4.2V, battery capacity 1400mAh, according to what we said above, the best charging rate 1C, need to reach 1400mA current to start charging, the voltage is 3.7V, after the voltage reaches 4.2V, start constant voltage charging, Stop charging until it reaches 0.01C, or 14mA.
4. What are the voltage and current of USB interface and charger respectively?
The current of USB port is 500mA, and the voltage is +5V. If you turn on HWinfo during the charging process, you can also see the External Power item, which is 500mA charger designed for iPhone. I think you all understand what the small white square that can be plugged into the Power socket is. I don't have to say this anymore, do I? To sum up, when you use USB to charge, the voltage is +5V, while the current is only 500mA. We know from the answers to questions 1 and 2 that this method will increase the battery capacity, which is very cool to use. But it will shorten battery life. When using a charger to charge, you might ask, didn't you say the best rate is 1C? That iPhone should be 1400mA charging current to ah, yes, but the country has a provision, the national standard of low rate charging is 0.2C (arbitration charging system), but also to the iPhone 1400mAh capacity of the battery as an example, is 280mA, the smaller the theory of the battery is more beneficial. But you can't wait three days to charge a battery. (Capacity mAh = current mA× time h) So Apple chose 0.7C, most batteries are between 0.5C and 0.8C 5 You can choose! Obviously some people use USB charging and it feels longer, but that comes at the expense of battery life
