The core technology of mobile power supply lies in the smooth discharge current and voltage curves when charging mobile phones. It is closely related to important technical indicators indicating whether it will damage the charging equipment. The test should be based on an authoritative third-party test report.
For mobile power supplies, it has a certain emergency function. When many digital product power supplies cannot store electricity, they can be powered by some devices to ensure the normal operation of digital products. For example, solar mobile power supplies, hand crank generator mobile power supplies, and smartphone backup power supplies are appearing in the market.
The craftsmanship of mobile power supplies means that the design of the product appearance incorporates popular or niche consumer aesthetics.eurs. As electronic products that are portable and have certain functions, consumers pay great attention to the aesthetics of their appearance. Therefore, as major manufacturers not only increase innovations in battery power management technology, they also increase research and development of product appearance. which meet the aesthetics of consumers.
Function expansion circuit
Function expansion covers common needs of outdoor activities, including high-brightness emergency night lighting, alarms outdoor anti-theft security and camping mosquito repellent.
It is divided into four types internally: traditional discrete, software three-in-one, hardware three-in-one, synchronous rectification and software three-in-one synchronous rectification.
The traditional separation is MCU, load management, sDC-DC separation and the 1A efficiency is 88%. The advantage is that it has been widely accepted by the market. The most serious problem is that in the case of a 2A output, the efficiency is low (around 83%) and the PCB heats up very seriously.
The three-in-one software is MCU plus external MOS, synchronous rectification, and the 1A efficiency is about 91%.
Three-in-one hardware is achieved through hardware and software cannot be changed. 1A efficiency is around 86%. The problem is that it has non-synchronous rectification, low efficiency and significant heat generation when outputting 2A.
Synchronous rectification has an efficiency of 93% at 1A and 88% at 2A. The biggest advantage is that it is small and generates little heat. The disadvantage is that the price of synchronous rectification DC-DC chips is too high.
Three in one synchronous rectification software, the efficiency of 1A can reach 95% andthe efficiency of 2A can reach 90%. It can achieve high charging and discharging efficiency without generating heat, low cost and good performance. The downside is that it requires strong technical software and hardware design.
Polymer battery: the standard voltage is 3.7V, has many shapes, can be customized, has large capacity, and is widely used, such as: mobile phones, MP4, speakers portable speakers, etc. The advantages of polymer battery mobile power supplies are that the appearance is less affected by the shape of the battery core, most of them are very fashionable, can be made lighter and thinner, more portable and more safe. The price is relatively high, which puts relatively strong pressure on stocks.
18650 lithium battery: standard voltage 3.7V, small size, large capacity, standard voltage 3.7V, mainly used in phigh-end products such as laptops. The characteristic of 18650 lithium battery mobile power supply is that its appearance is greatly affected by the shape of the battery core. Although it is cost-effective, its portability is relatively poor. The 18650 lithium battery is cylindrical, and a single cell is generally 2000-3400 mAh power.
AAA NiMH battery: standard voltage 1.2V. The capacity is relatively small. Widely used in household appliances, toys, etc.
Lithium iron phosphate battery: standard voltage 3.65V, also called ferroelectric, has long life, safe, environmentally friendly, supports fast charging and discharging and is often used in power batteries and high-end mobiles. power supplies and other areas.
Boost system:
Traditional Boost technology basically adopts the Boos methodt DC to DC. The conversion efficiency of domestic technology is generally low, generally between 50% and 70%. Taiwan's is 75 to 80%. The United States is relatively higher. There are also voltage reduction solutions, which are relatively effective, but require high consistency of the battery cells, so they are rarely used.
Calculate the output power of the power supply based on the conversion efficiency of the product:
Actual output capacity = (mobile power supply capacity 7800 mAh x 3.7Vx conversion rate 85%)/5V = 4906mAh
Charge management system:
At present, the home charge management system is relatively mature, and Smart IC monitors the entire charging process. Common management ICs include PT4056, PX40, etc. 5000 mAh charging time takes around 6 hours with a 1A charger. Charging too quickly willa negative impact on battery life.
The issue of mobile power conversion rate has always been a great concern for consumers, which is directly related to the problem of calculating how many times mobile power can charge the mobile phone client. Therefore, high conversion rate is also a technical improvement that mobile power manufacturers are constantly pursuing, and this has also led many manufacturers to set false standards in mobile power capacity and conversion rate. Here we will answer for you vividly "How many times can a mobile power supply charge my cell phone". 18650 Battery Cell
18650 is the name in the industry, which refers to a cylindrical battery with a diameter of 18mm and a length of 65mm. International manufacturers such as Sanyo, Panasonic, Samsung, Sony, etc. HeThere are also many manufacturers in China who produce and sell 18650 batteries. Most of the mobile power supplies on the market use 18650 batteries. In order to reduce costs, they mainly use domestically produced products. Large imported manufacturers. 18650 battery cells.
The most common capacities of 18650 are 2200 mAh, 2400 mAh and 2600 mAh. According to reports, the 18650 can currently reach a maximum single-cell capacity of 3,400 mAh. Mobile power supply using 18650 battery cells is basically realized by connecting the above specifications in parallel. The 18650 is generally packaged in a cylindrical steel shell, containing lithium ions in a liquid state. Because this is already an industry standard specification, the 18650 can only be cylindrical. If you see a thick, wide shape when purchasing a power supplymobile tation, you can be sure that the 18650 battery cell is used.
When it comes to safety, batteries are energy bodies and serious quality accidents can occur in extreme cases. Since the 18650 battery cell is packed in a steel shell, it will explode in the most severe case as we know. Most laptop batteries use 18650 cells, and in the first few years , Sony suffered a batch recall due to serious battery quality accidents.
Since 2014, many mobile power supplies on the market used poor quality 18650 batteries in order to reduce costs and achieve low prices, which were difficult to guard against. A mobile power supply is a product that users carry with them. If the quality isn't up to par, it's like carrying around a time bomb. Therefore, whencat of a product, you must comprehensively consider the brand and price of the product. and don't blindly look for the cheapest.
Polymer batteries
Polymer batteries are generally made of a mixture of lithium cobalt oxide, lithium manganate and ternary lithium. The outer packaging is mainly made of aluminum plastic film and the middle. The lithium substance comes in the form of a paste, so the shape can be customized as desired, such as ultra-thin batteries such as 0.25mm. Therefore, mobile power supplies using polymer cells can also be designed to have a more flexible appearance. For example, some ultra-thin mobile power supplies on the market and iPhone 4 back-clip batteries use polymer batteries.
Polymer battery packaging is flexible and has no fixed specifications or sizes like18650. Its capacity directly depends on its size and the type of raw materials used.
For polymer batteries, the biggest safety risks are liquid leaks and short circuits, which can lead to swelling of the packaging. In the worst case, a burn may occur. Compared to 18650 batteries, polymer batteries are relatively safer. However, combustion can also pose safety risks. Therefore, users of mobile power supplies are recommended to try not to place the mobile power supply in a flammable environment.
In the market in 2014, the mobile power banks with the largest shipping volume still used 18650 battery cells. Most products of brands such as Pinsheng use 18650 battery cells , while most high-end mobile power supplies use. 18650 battery cells. Ituses polymer batteries. From the perspective of safety, it is recommended that users consider using polymer battery cells when purchasing mobile power supplies, especially large capacity mobile power supplies, such as above 8000 mAh . If multiple 18650 battery cells are connected in parallel, an explosion will occur. very scary, and polymer batteries will never explode, at most they will produce flames.