battery knowledge
Understanding battery knowledge is the basis for all types of electric models, especially for model airplanes. After several decades, the power battery has been greatly developed. Nickel-metal hydride batteries, lithium-ion batteries, and lithium polymer batteries have been introduced one after another, and they have appeared on the stage of the model aircraft.
what is the power battery
A model that uses an electric motor as an engine is called an electric model, and a battery that drives such a motor is called a power battery. It is quite different from batteries for other uses and is critical to the performance of model aircraft.
the type of power battery and its development profile
There are many types of batteries that can be used as power for electric model airplanes, such as solar cells, silver-zinc batteries, lithium batteries, nickel-cadmium batteries, and nickel-hydrogen batteries. The output current of the solar cell is too small, and the area must be made large to make the electric model aircraft fly, and the cost is very expensive, so few people care about it. The specific energy of silver-zinc battery (the ratio of energy to weight, in watt-hours/kg) is very high, and the discharge capacity of high-current is very strong, but the repeated service life is short, and the price is expensive, easy to leak, can not be dumped, and now Nobody cares. At present, the mainstream varieties used in aircraft models are the nickel series (including nickel-metal hydride batteries and nickel-cadmium batteries) and emerging lithium batteries (including lithium-ion batteries and lithium-polymer batteries).
The electric model aircraft became popular in Europe and the United States in the 1970s, mainly because of the strong and rechargeable nickel-cadmium batteries that were put into practical use and mass production. Nickel-hydrogen batteries, which were introduced more than 10 years later, showed an advantage of 50% to 100% higher than nickel-cadmium batteries in terms of specific energy. However, in terms of high current discharge capability, it has been significantly behind the nickel-cadmium battery for a long time. However, by the beginning of the 21st century, nickel-metal hydride batteries have been as good as nickel-cadmium batteries and even more than nickel-cadmium batteries. In addition, its memory effect is small, and its environmental pollution is small. It has been widely used in aircraft model power. One of the mainstream varieties. Nickel-cadmium batteries have been banned in Europe due to serious pollution to the environment and are being phased out in China.
In the early days, lithium batteries were only used as disposable batteries. They were not rechargeable. Their specific energy was extremely high, but the internal resistance was so large that they could not provide a large current to fly the electric model aircraft. But by the end of the last century, there were already rechargeable lithium batteries, but the lithium batteries at that time were very expensive, and the discharge capacity was barely able to keep the planes flying flat (climbing on silver-zinc batteries).
In the early days, the research on lithium batteries was mainly for military purposes. Later, driven by the huge economic benefits of civil use, people paid more attention and input to them, and thus made breakthroughs in the late 20th and early 21st centuries.
At present, lithium batteries have eliminated nickel-cadmium batteries and nickel-hydrogen batteries in the fields of mobile phones, video cameras, and portable computers. The promotion of lithium batteries in remote-controlled model aircraft is later than in the field of mobile phones.
Initially, foreign enthusiasts tried to use the lithium-ion battery used in mobile phones to fly the aircraft, and achieved excellent results that the blanking time was much longer than that of nickel-cadmium batteries. Then, it attracted the manufacturers of the battery and model industries to compete. However, the lithium-ion battery is soon combined with the aircraft model, and its sibling lithium polymer battery shows a stronger and more suitable aviation model in terms of high current discharge capability, thus pushing the lithium ion battery to one side, quickly It has grown into the mainstream of the current model power battery. After several years of development, lithium polymer batteries are currently superior to nickel-cadmium batteries and nickel-hydrogen batteries in terms of high-current discharge capability, but they are only promoted due to various factors such as charging, maintenance, life, and price. Subject to certain restrictions. From the perspective of long-term development, the RC airplane power battery will be the world of lithium batteries for a long period of time.
Post time: Apr-02-2020
