lifepo4 18650 battery

　　lifepo4 18650 battery repair technology

　　Causes of sulfation in batteries

　　Lead-acid batteries have a history of more than 100 years and are a widely used power source. It has good reliability, easy-to-obtain raw materials, and low price. It currently has a market share of about 95%. In actual use, if the battery is not properly used and maintained, such as often undercharging, not charging or overdischarging, a hard and poorly conductive coarse-grained lead sulfate will gradually be produced on the negative plate. This kind of lead sulfate is difficult to restore by charging with conventional methods. During charging, the charge acceptance ability is very poor and a large amount of gas is released. This phenomenon is called "irreversible sulfuric acid sulfurization", or "sulfidation" for short. Coarse-grained lead sulfate blocks the pores of the plates, making it difficult for the electrolyte to penetrate and increasing the internal resistance, thus reducing the battery capacity.

　　The main lifepo4 18650 battery repair technologies that have emerged in recent years include:

　　•Using high current charging to cause large lead sulfate crystals to produce negative resistance breakdown and dissolve.

　　Experiments have found that this elimination of sulfide can only achieve a temporary effect, and will cause aggravated water loss and softening of the positive plate during the elimination of sulfide, causing serious damage to the battery life and making it difficult to adopt.

　　•Negative pulse

　　This method has been used for more than 30 years. The principle is to add negative pulses during the charging process, which has an effect on reducing the temperature rise of the battery. However, the repair effect on "sulfide" is not obvious. Its repair rate is 20%. It is currently used more , is an obsolete product, with a regular price of about 1,300 to 1,600 yuan.

　　•Add active agent

　　Using chemical methods to eliminate lead sulfate crystals not only costs high and increases the internal resistance of the battery, but also changes the original structure of the electrolyte. The service life after repair is short, and the repair rate is about 45%.

　　•High frequency pulse

　　Pulse waves are used to re-convert the lead sulfate crystals into reversible lead sulfate with fine crystals and high electrochemical properties, so that it can normally participate in the chemical reactions of charge and discharge, and the repair rate is about 60%. Better than negative pulse. However, due to its long repair time, it takes more than dozens of hours or even a week, and the efficiency is low. It is not good for repairing severely "sulfated" batteries. However, the technology is simple and is currently used by many manufacturers. The market price is about 2,000 yuan. .

　　•Combined resonant pulse

　　Reasonably control the leading edge of the repair pulse, and use the method of high-order harmonics in the charging pulse to resonate with the large lead sulfate crystal to eliminate battery sulfation during the repair process. This method can be used to repair the battery with high repair efficiency. , causing little damage to the battery, greatly reducing the environmental pollution caused by lead-acid batteries, extending the battery life, and reducing the user's huge expenses for battery replacement, so it has a bright future. The disadvantages are complex equipment technology, high cost, and high requirements for pulse front control and resonance technology. The market price is about 2,200-7,800 yuan for the -4 type (4 independent charging and discharging), and 8,500-15,000 yuan for the -20 type (20 independent charging and discharging).

　　The principle and method of eliminating vulcanization by composite resonance method

　　Although we know that the main way to prevent battery sulfation is to prevent the battery from being uncharged and over-discharged, in actual use, this phenomenon still often occurs. Previously it was considered "irreversible" when this happened. Traditional treatment methods are relatively complex, using high-current charging; active agent replacement; positive and negative pulse charging, etc. These methods have low repair success rates and have certain negative effects. The current method is a composite pulse repair method, which can turn "irreversible" into "reversible" and basically does not cause any damage to the battery plates. This is a major breakthrough in the lifepo4 18650 battery industry. The principle of pulse repair is relatively complicated. First of all, any crystal has a resonant frequency after its molecular structure is determined, and this resonant frequency is related to the size of the crystal. The larger the size of the crystal, the lower the resonant frequency. If charging uses a pulse with a steep front edge, frequency analysis using Fourier series can show that the pulse will produce rich harmonic components, with large amplitudes in the low-frequency part and small amplitude in the high-frequency part. In this way, the energy obtained by the large lead sulfate crystal is large, and the energy obtained by the small lead sulfate crystal is small, resulting in the large lead sulfate crystal having a large resonance amplitude and being easier to dissolve than the small lead sulfate crystal during the positive pulse charging period. The so-called "crushing" of coarse lead sulfate crystals. Properly control the pulse current value and charge the positive plate with a smaller current density, which will basically not cause damage to the positive plate. For sealed batteries, the instantaneous charging voltage allows the oxygen produced by the electrode plate to be absorbed by the negative plate through oxygen circulation, and the battery will not lose water. So this is a "no loss" repair that differentiates it from other repair methods.

　　A high-frequency positive and negative pulse generator is used to continuously generate high and low frequency pulses on the battery. One of them can have the conditions to dissolve the large lead sulfate. The other is the pulse disturbance, which destroys the conditions for the continued growth of the large lead sulfate. This method overcomes the The limitations of previous repair technologies include rapidity, about 8-12 hours, high repair efficiency, low power consumption, and will not cause battery water loss, softening of the positive plate, or change of the original structure of the electrolyte. It is suitable for severely sulfated lead-acid. The battery repair effect is 3 to 4 times that of the past, and the repair rate reaches more than 90%. The application of this technology reduces the number of scrapped batteries.

　　lifepo4 18650 battery repair technology

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