Mobile power security is constantly taken by the people of the problem, but the chaotic situation in the market of mobile power factor is also more and more insecure. Mobile power must have: short circuit, overcharge, over discharge, constant current, constant voltage and other protective measures, there should be high-performance power management technology. So as to make buy the rest assured that with the peace of mind.
Mobile power is a set of rechargeable batteries, boost, charge management in one of the portable devices. Chu dielectric generally use lithium batteries, lithium batteries because of relatively small size, large capacity, broad market liquidity, affordable, is widely used in digital products. Lithium voltage between 2.7-4.2V, the voltage drop along with a decline in consumption. The 2.7-4.2V voltage can not be directly charged to other digital products, digital products lithium because the voltage is 2.7-4.2V, the voltage potential between the same can not be charged.Therefore, the output power is outwardly mobile power boost system must be put voltage of 2.7-4.2V lithium boost to 5V, so you can charge it to other digital products, such as mobile phones, MP4, Tablet PC, PSP and so on.
Of course, the mobile power is not a one-off device, which can be reused hundreds of times. So when power mobile power after use, we must give mobile power charging. The principle is the same, and to charge the phone. Connect to 5V USB computer interface or USB Power Charger for charging mobile power. Therefore, there must also be an internal mobile power charging management system. Rechargeable lithium battery management system according to the voltage automatically adjusts the charge current. Process are: pre-charge, constant voltage charging and floating charge and so on.
Mobile power is composed of three parts, batteries part, the circuit part (booster systems and charging management system) and the housing section. The following describes each component.
Mobile Power Batteries:
Batteries are a core part of mobile power, mobile power is the power storage, in fact, is the battery. Commonly used polymer lithium battery, 18650 lithium battery, AAA NiMH batteries.
1 lithium polymer battery: standard voltage 3.7 V, the shape more, can be customized, with large capacity, inexpensive, widely used, such as: mobile phone, MP4, portable speaker. Polymer lithium battery is a kind of aluminum flexible packaging used in the structure of lithium-ion batteries, it is more than metal casing batteries safer, does not occur when working at high risk security risks. Its charge density, thickness is smaller, lighter, while the capacity is great, a lot of mobile phone battery is made using polymer batteries. Its resistance is small, even less than 35mΩ, greatly reducing the battery from the power, making the higher utilization of electricity. In addition, the shape can be customized, tailor-made according to the appearance of the shell, a lot of the appearance of small mobile power are based on flexible batteries.
2.18650 Lithium Battery: Standard voltage 3.7V, with small size, large capacity, mainly used in notebook computers and other high-end products.18650 is a steel, aluminum batteries, and its technical aspects are relatively mature. 18650 having a diameter of 18mm, a height of 65mm cylindrical battery, the capacity is usually between 2000-3000mAh. Mobile power in the market most of the 18650 are using lithium cobalt oxide used as cathode material for batteries, its single nominal voltage of 3.7V, the charging voltage of 4.2V. Such batteries Compared to the previous nickel-metal hydride and nickel-cadmium batteries greater capacity, longer life expectancy, the number of cycles of charging and discharging can reach more than 500 times, and higher safety factor, non-toxic and environmentally friendly.
3. AAA NiMH batteries: Standard voltage 1.2V. Capacity is relatively small. Should be widely, household appliances, and other players.
Boost mainstream technology basically uses DC to DC boost mode.Conversion efficiency of domestic technology generally low, generally in the 50-70%. In 75-80% of Taiwan. The United States will be relatively higher. Also there is relief programs, the efficiency is relatively high, but the consistency of batteries with high requirements, so rarely used.
Depending on the product supply output power conversion efficiency calculation:
5000mAh mobile power with an example: the actual output capacity = (mobile power capacity 5000mAhx3.7Vx conversion rate 85%) / 5V = 3145mAh
Charge Management System:
Currently charging management system is relatively mature, intelligent IC monitors the entire charging process. Mainstream Management IC with PT4056, PX40, etc. Charge time 5000maH about 8 hours. Fast charging of the battery life has adverse effects.
1 plastic shell: Average mobile power are ABS / PC-based materials.
(2) Metal shell: Aviation aluminum shell.