Several common methods of battery charging
1. Ni-Cd and Ni-MH battery charging:
a. constant current charging: the charge current is in a certain valueone in the whole process of charging , this method is the most common.
b. constant voltage charge: both ends of charging power maintains a constant value in the process of charging, the circuit current gradually decreases as the battery voltage increases.
c. constant current constant voltage charging: constant current charging the battery to CC for the irst time, when the battery voltage rises to a certain value, the voltage remains CV, the circuit current is reduced to a small, tends to 0.
2. Lithium battery charging: constant current constant voltage charging: constant current charging the battery to CC for the first time, when the battery voltage rises to a certain value, the voltage remains the same CV, the circuit current is reduced to a small, tends to 0
Types of Fuel batteries
Currently, there are five kinds of known types of fuel batteries. their name is related to the corresponding electrolyte.
(1)alkaline fuel battery uses potassium hydroxide solution as electrolyte. This electrolyte was highly efficient (up to 60 1 90%), but affect the purity of impurities, such as carbon dioxide is very sensitive. Hence the need to run in the pure state of hydrogen and oxygen. This limit will be applied to space flight and the international engineering and other fields.
(2)proton exchange membrane fuel battery usesvery thin plastic film as the electrolyte. This electrolyte has a high power-weight ratio and a low operating temperature. Is applicable to fixed and mobile devices an ideal material.
(3)phosphoric acid fuel battery uses phosphoric acid under high temperature 200 ℃ as its electrolyte. Is very suitable for decentralized cogeneration system.
(4)molten carbonate fuel battery operates temperature up to 650 ℃. This highly efficient batteries, but the material needs of the demands are high.
(5)solid oxide fuelbattery uses a solid electrolyte (Diamond oxide), the performance very good. They need to adopt the appropriate materials and processes for dealing with technology, because the battery operating temperature is about 1000 ℃.
At present, some research institutions, the ongoing fuel cell development and research. However, internationally recognized is that in the past decade, PEMFC technology has been developed to a practical stage. However, its process of industrialization has not yet matured. And the need to make further efforts to reduce the cost of this technology.
What is the module power supply
Module Power supply can be directly mounted on a printed circuit board, which is characterized for application specific integrated circuit (ASIC), digital signal processors (DSP), microprocessors, memory, field programmable gate array (FPGA ), and other digital or analog load to provide power. In general, these modules are called point of load (POL) power supply system or the point of use power supply system (PUPS). Because of many advantages of modular structure, the module power is widely used in switching equipment, access equipment, mobile communications, microwave communications and optical transmission, routers and other communications and automotive electronics, aerospace and so on.
In particular, in recent years, due to the rapid development of data services, and distributed power supply system spreads, the module power supply has exceeded the increase in a power supply. As the semiconductor technology, packaging technology and high-frequency soft-switching's large-scale use, the module power supply power density increases, more and more high conversion efficiency, applications are increasingly simple.
at is the direct methanol fuel battery?
The direct methanol fuel battery belongs to one of the categories of the proton exchange membrane fuel battery .It directly use aqueous solutions of methanol as fuel and steam supply source, not through the restructuring of devices without having to re-methanol, gasoline and and then remove the hydrogen such as natural gas for power generation. Compared to proton exchange membrane fuel battery, direct methanol fuel battery low temperature of Health electricity, fuel components and battery low-risk features such as simple structure, so that direct methanol fuel battery portable electronics applications may be mainstream.
Direct methanol fuel battery
Direct methanol fuel battery is a proton exchange membrane fuel battery as a variant, it directly uses methanol , rather Needless to pre-restruct. Methanol changes into carbon dioxide, proton and electron at the anode , as the standard proton exchange membrane fuel battery, as protons through the proton exchange membrane and oxygen in the cathode reaction of electrons through the external circuit to reach the cathode, and doing work.
The expectations of the battery operating temperature is 120 ℃, which is higher than the standard proton exchange membrane fuel battery , its efficiency is about 40%. The disadvantage is that when low-temperature methanol is converted to hydrogen and carbon dioxide,when the conventional proton exchange, membrane fuel batteries need more platinum catalyst. However, this increase in costs can be due to easy access to liquid fuels and will be able to work on the revitalization Needless to dwarfs. The use of direct methanol fuel battery technology is still in its early years of development, it has successfully demonstrated and can be used as mobile phones and laptop computers power supply, the future for a specific end-user also has potential.
How long the battery can store?
On the theory, when the battery stores, the total energy will loss some. Inherent in the electrochemical cell structure determines the battery capacity of inevitable loss, mainly due to the self-discharge. Usually the size of the self-discharge bears on the cathode material solubility in the electrolyte and its instability after heat (easy to self-decomposition). Rechargeable batteries self-discharge is high than a battery . The battery types, battery-month self-discharge rate is not the same. Generally 10-35% change. A battery self-discharge is significantly lower, at room temperature it does not exceed 2% per year, with the self-discharge during storage is accompanied by increase in battery internal resistance, which can cause the battery to reduce power load, while in the discharge current is larger cases, the energy loss is a very significant change.