Types and advantages and disadvantages of power banks

Mobile power supply, mobile charger (line power, line charge, charge bank, urine bag, wet nurse);Power bank is a portable charger that can be carried by individuals and can store electric energy by itself. It is mainly used to charge consumer electronic products such as handheld mobile devices (such as wireless phones and laptops), especially in the absence of external power supply. Its main components include: a battery to store electrical energy, a circuit to stabilize the output voltage (DC-DC converter), and most mobile power supplies come with a charger to be used as a built-in battery for charging.

The Power Bank is actually a large capacity portable power supply that is convenient and easy to carry. It is a collection of storage, boost voltage, charge management in one portable device.

The charging plug of the power bank itself can charge mobile devices directly through the AC power supply and it has a storage device, which is equivalent to a hybrid of a charger and a standby battery. Compared with the standby power supply, it can simplify the device of a charging plug. Compared with the charger, it has its own storage device, which can provide backup power for digital products when there is no direct power supply or when going out.

Main species

1. According to the classification of batteries

The battery bank in the market generally uses ordinary 18650 lithium cell and advanced lithium polymer cell. Advanced lithium polymer cell has better security than 18650 lithium cell. In the case of economic permit, it is recommended to choose advanced lithium polymer battery charging bank.

2.According to the charging mode classification

2.1 linear power bank: the use of pure resistance current limiting voltage reduction or charge management chip voltage reduction, the input 5V voltage directly to the battery required voltage, the middle through the triode amplification or chip internal comparator amplification for current limitation. It has the advantages of short development time and high success rate.

2.1.1

Disadvantage 1): This kind of line is through linear voltage regulation constant current to consume excess energy to achieve the purpose of voltage reduction charging, the temperature is quite high and the charging current can not be large, because the larger the charging current, so the energy consumption will be larger, the same heat dissipation area should be increased.

2.1.2

Disadvantage 2): this kind of line charging battery is easy to polarization, the greater the charging current will be the greater the polarization area, the lower the capacity will become, the longer the battery will become no capacity. The best way to reduce the polarization is to charge the battery after it is used up. Reducing the number of times the battery is charged is equal to extending the battery life (polarization is the accumulation of oxides that prevent electrons from moving). Linear charging usually has three stages: constant current - constant voltage - trickle current.

2.2 pulse charging bank: The use of CMOS electronic switch, through the control of the switch time and frequency for step-down, constant current charging also known as PWM control charging. The intermediate control process needs to calculate and adjust the width or frequency of PWM through the CPU port detection to control the data to complete the charging process, the disadvantage is that this line technology is quite complex. Pulse charging bank usually has four stages: slow charge constant current, fast charge constant current, fast charge constant voltage and trickle repair.