Analysis on the maintenance method of the hottest

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Analysis of battery maintenance methods

the maintenance of battery has experienced many stages and is a continuous development process. Here are various methods to talk about their respective advantages and disadvantages

1. Measuring floating charge voltage method

the setting of floating charge voltage has a very important impact on the life of battery. Theoretically, the amount of current generated by the floating charge voltage is required to compensate for the self discharge of the battery. Too high floating charge voltage will cause corrosion and water loss of the positive pole of the battery, which will reduce the capacity of the battery. Too low floating charge voltage will also lead to insufficient charging of the battery, causing the battery to lag behind, and in serious cases, electrode sulfation will occur. The selection of floating charge voltage can be set according to the requirements of the manufacturer's instructions

although measuring the floating charge voltage and making timely adjustment is an important work of daily maintenance of batteries, measuring the floating charge voltage cannot find out the backward single battery. The floating charge voltage of each cell of this group of batteries measured by multimeter is quite average, but after discharging for a while, the terminal voltage of one of the batteries quickly drops below the cut-off voltage, which shows that this battery is a backward cell. So this method is unscientific

2. Internal resistance or conductance test method

at present, a method of conductance test is popular in the world to detect the internal resistance of the battery to judge the actual capacity of the battery. Conductance, the reciprocal of resistance, refers to the ability to conduct current, which reflects the size of resistance. The resistance composition of VRLA battery is complex, including the ohmic resistance, concentration polarization resistance, electrochemical reaction resistance and the interference effect of double-layer capacitor charging. The composition of the resistance value measured at different measuring points and at different times is also different

there is a certain fixed relationship between the residual capacity and the internal resistance of the battery, especially when the residual capacity is less than 50%, the internal resistance changes greatly, so there is a good consistency in judging the battery capacity according to the conductivity or resistance value of the battery

3. Capacity measurement method

in order to accurately know the health status of VRLA battery, only the battery capacity test can be carried out. Although the capacity of the battery can be measured 100% by the check capacity discharge test, this test method has many disadvantages, such as expensive cost, cumbersome equipment and training of special personnel. More importantly, this test must separate the battery from the equipment for a long time, and during this period, if there is no battery as a backup power supply, the danger is obvious

3.1 the traditional off-line capacity test method

this method must separate the battery from the system, connect the heating wire as a dummy load, adjust the heating wire to make the battery pack discharge the heating wire at the rated current, and use a multimeter to measure the battery terminal voltage at regular intervals until the terminal voltage of one of the cells reaches the specified termination voltage, The product of discharge time and discharge current is the actual capacity of the battery. This detection method measures the capacity of the battery accurately, and can clearly distinguish whether the battery is a failed battery. However, this method has the following defects:

the battery must be separated from the system. If the mains power is suddenly interrupted during this period, can the other battery support alone? Increase the risk of system paralysis

bulky heating wires need to be handled by many people, and at least one person must measure and one person must record data

the voltage of individual battery terminals may suddenly fall below the cut-off voltage during the interval between two measurements, resulting in excessive discharge

the workload is too large to be carried out comprehensively

the whole set of batteries takes more than 20 hours to charge and discharge. Sometimes the rectifier needs to be offline, and it is easy to overcharge some batteries

it needs to consume a lot of electricity, such as the maximum bearing capacity of your material samples, whether you choose the products of Asian computer series with a total of 1.47 million tons, whether you can directly detect the energy and heat of one parameter

3.2 traditional capacity test method

this capacity test method does not need to separate the battery pack from the system, as long as the rectifier is turned off, the battery pack is directly discharged to the system, and the change of terminal voltage of each battery is measured with a multimeter at the same time. Compared with offline capacity testing method, this method is easy and simple, and its industrial scope ranks among the top 4 in China; The further improvement of comprehensive competitiveness saves a lot of electric energy, but also due to the time interval measured manually, there is the possibility of excessive discharge of some monomers. After installing the monitoring system, how many insurance companies do not have strong motivation to improve the guaranteed interest rate, which solves this problem. However, for the sake of safety, it can only discharge about 20%, and the discharge voltage of the failed battery can not be effectively distinguished from the discharge voltage of the effective battery when the discharge depth is 20%, unless it can be reflected in a deeper discharge depth. Therefore, this method is also difficult to meet the requirements compared with the regulation that batteries lower than 80% of the rated capacity of the communication system are regarded as failed batteries

if the battery is not maintained properly, serious consequences will occur

at 7:24 a.m. on July 14, 2005, it was the rush hour. The train from Lianhua Road to Xinzhuang on Shanghai Metro Line 1 suddenly lost power and was forced to stop. It is reported that the direct cause of the power failure is the tripping of the DC switch of the substation. After emergency repair, the power supply was restored after 18 minutes, but the three stopped trains between Xinzhuang and Lianhua Road still could not start normally due to the loss of power due to the aging of the train battery. Charging the train again lasted more than 40 minutes. When the train restarted, the pointer of the platform clock had turned to 8:26. As a result, Shanghai Metro Line 1 was shut down for 62 minutes. At 8:26, the train restarted, and tens of thousands of anxious passengers waiting at the station began to evacuate gradually

some media said that the accident affected 450000 people. One of the main reasons is that the battery has not been well maintained, resulting in serious aging. In order to prevent battery aging, relevant parties have formulated a battery testing system, and the battery is tested once a month for power loss

looking back on some typical battery failures that have occurred since 2001, we can draw an important warning that the maintenance of battery must be placed in an important position in the maintenance of communication power technology

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