My answer to Will charging with a portable power bank damage cellphone's battery life?
Answer by Allen He:
is popular right now as more and more people use them. Previously, when we buy a new mobile phone, we always buy several batteries for the energy storage. With the appearance of power bank, the situation is changed. We only need one battery if we have a power bank on hand.
So is power bank harmful to the PCBA or battery of mobile phone and PCBA? We could talk about it in two aspects.
how do power bank works ?
What is the mechanism of its working?
This power bank can deliver 4.5 Volts with reasonable current to charge the Mobile phone quickly. It can charge the Mobile phone 3-4 times . The Power bank uses a 4.5 V Rechargeable battery that can be charged using the Mobile phone charger or from the USB port.
4.5 V Rechargeable battery is now available with a rating of 1 Ah, 1.5 Ah, 2 Ah etc for less than Rs.100. This battery can be used or use a high efficiency Lithium battery.The Mobile phone battery is 3.6 V so 4.5 V from the Power bank is sufficient for charging. Transistor T1 act as a current regulator during charging the Mobile battery.
1.When we discharge the power bank, we should look at the output voltage whether it is constant current charge and constant voltage charge. The voltage of charging of a mobile phone battery is 4.2V~5.2V. As the output voltage for most power banks are about 5V, so it will be no problem.
2.When we charge the power bank, it will be better if we keep it constant current charge and constant voltage charge. The ordinary standard of charging battery for mobile phone is 5V/500mA~1000mA. And the standard for many old mobile phones are 5V/300~500mA.According to the figure, many power banks could meet the requirement.
3.The conclusion is that if the power bank works with constant current charge and constant voltage charge, the it will be not be harmful to the mobile phone battery and PCBA.
Tips: Protection board, the board is like a computer motherboard, if good motherboard can drive all of the parts very easy in operation and protection of power bank supply board can make the inside of the capacity and safety to achieve the comprehensive, but not good don’t do, there will always be some, in order to pursue interests regardless of the quality of the products businesses, is the market at present most of the use of power bank supply using cobalt acid lithium protection board, power bank supply volume is small and exquisite, made of this material but poor safety performance, resistance to overcharge performance is poor, not suitable for high rate discharge, Poor circuit board, the overcharge protection functions such as missing. Not only for power bank supply, short service life are more likely to cause explosion; So the design of the protective plate must be reasonable and practical.