The base station battery is from the current use, there is a problem that the battery capacity is too fast, the service life is short, and the battery capacity is only 30% ~ 40% of the battery, and some is only 10% ~ 20%, and most base stations battery operations have been operated in 1 to 4 years, with only about 50% of their nominal capacity, far from its design life, compared with the exchange of exchanges, and its service life is also Greatly reduced. This paper analyzes the damage causes of the battery during the operation of the base station, and proposes a method of extending the service life of the base station battery.First, the definition of battery life
The service life of the battery is generally referring to the use period of the floating state. For batteries operating in non-floating state, their life is measured from two dimensions of circulation discharge and discharge depth, as shown in Table 1. So don't simply use how many years can use to measure the life of the battery.
For the number of cyclic discharges of the battery, it must be sufficiently electrical energy after the battery is discharged, and the power charging time is required for at least 24 hours (according to YD / T799-2002). For the insufficient charging, the number of cyclic discharge is difficult to determine, and it is definitely lower than the data described in Table 1.
The impact of discharge depth on battery life is also very large, the deeper the battery discharge depth, the less the number of cycles, as shown in Table 1, so the depth discharge should be avoided.
Second, the factors of the end of battery life
For valve-controlled sealed lead-acid storage, there are four failure modes: positive electrode plate corrosion, loss of water, thermal out of control, sulfate. Among them, the positive plate grid corrosion due to the improvement of the alloy process technology, the corrosion speed is very slow, generally 10 to 15 years.
There is more ways to lose water: the throttle design is unreasonable, frequently open; the power supply is frequently charged; the ambient temperature is too high. Among them, high temperatures are the most important factors, and high temperatures can accelerate the battery's lossless speed, resulting in a decrease in battery capacity. Based on 25 ¡ã C, when the battery operates rise 10 ¡ã C, the life is reduced by 50%, as shown in Figure 1.
Thermal out of control refers to the formation of a positive feedback between the heat generated during the charging process, the temperature and chemical reaction forms a positive feedback, and out of control. The thermal out of control is devastated to the battery, causing the battery case to deform, and severely causes the battery explosion. The reason for thermal out of control is that the ambient temperature of the machine room exceeds 45 ¡ã C, and the floating charge voltage is too high at high temperatures (without temperature compensation function), the charging current exceeds the design value (more than 2.5C10).
Sulfate refers to the formation of white hard sulfate crystals on a plate, and the particles are relatively large, low activity, and it is difficult to convert to lead to lead to active substances, resulting in a decrease in battery capacity or functional decline. The cause of hydrochlorination is that the battery has been stored for a long time before installation (more than 3 months), continuous over-discharge or often excessive discharge or small current depth discharge, the ambient temperature is too high or too low, often charged, no periodic execution Both.
Third, affecting the life of the base station battery
Many base stations are remote, and the AC power supply is unstable or frequently poweredized. Even without AC electricity; the base station does not have air conditioning or outdoor sites, the ambient temperature is high; the site is remote and the number is much, and it is not possible to make refined maintenance. The above is the basic condition of the base station battery work environment.
Through the analysis of the battery damage of China's base station, the specimen analysis of several provincial batteries in Xinjiang, Zhejiang, Shaanxi, Yunnan, and combined with the damage data of overseas Vietnam, Egypt, Pakistan, Ethiopian base station, we conclude the life of the battery. There are several factors:
(1) Exchange frequently
Frequent power failure, long power failure, no regular power failure, so that the battery is often charged and discharge, or the base station does not alternate electricity, alternately powering through diesel generators and battery, is a major reason for the reduction of battery capacity and life. .
The base station is too high, and the battery is stopped several times, and even continuously power outage, the base station battery is not fully charged after discharge, and the battery is in an under charge. If there is any incident, it will cause the battery capacity to accumulate loss, sulfate is intensified, and the battery capacity will drop in a short period of time, and its service life will be terminated.
(2) Battery storage time is too long
The battery exists in the storage process. If the supplement is not added for a long time, there will be a sulfate phenomenon. This phenomenon is not improved in time, and the battery capacity will decrease or even damage. In the storage process, the battery temperature has a very large effect on the capacity, as shown in Table 2.
(3) The ambient temperature of the base station is too high
After the base station is powered up, the air conditioner is stopped. Since the base station is a closed machine room, the indoor temperature of the base station will rise sharply. Temperature is too high to increase the water inner water in the valve controlled battery, and the electrolytic liquid saturation decreases (the electrolyte decrease in the glass fiber cotton diaphragm) reduces the capacity of the battery and shorten the service life.
(4) Battery installation opening quality
Whether the installation of the battery is in line with the standard, the use of the battery is very much. When the battery is not tightened when the battery is installed, the contact resistance between the terminal and the connector increases, which will generate a large amount of heat when charge and discharge, which causes the entire set of battery damage; the battery temperature sensor is not installed or Installing errors, when the temperature is high, because the charging voltage cannot be adjusted to the appropriate value, the battery is thermal out of control, resulting in battery damage; when the opening is not adjusted to adjust the battery management parameters to the reasonable value, resulting in a battery damage.
(5) Do not set the battery management parameters correctly
The switching power supply involves the parameters of the battery management, the battery capacity, charging current coefficient, all floating voltage, one or two lower voltage, automatic basic charge conditions, temperature compensation voltage, if these parameter settings are unreasonable, will life of the battery Result in an impact. For example, a two-down voltage set voltage is too low, so that the battery has an over-discharge or even depth over-discharge phenomenon, aggravation of the battery negative plate sulfate will cause the battery capacity to decrease, shortened service life. The battery capacity is set incorrectly, affecting the battery charging current, causing the battery charging current to be too large and damaged.
Fourth, the method of extending the battery life of the base station
Based on the factors that cause the battery life of the base station, combined with the actual situation We provide a method of extending battery life.
1. Increase the power supply
For frequently-stop sites, by increasing the fixed oil machine or mobile oil machine to ensure that the battery can be supplemented in time after power failure, or avoiding the battery depth discharge. Sites for excessive frequently-powered electricity, in addition to the above methods, special batteries need to be taken to solve problems, such as using Gel batteries. GEL is more than 1.5 to 2 times higher than the number of AGMs in the life life. It is recommended to use a 2V battery in this site to avoid using 12V batteries.
For sites without AC electricity, the diesel generator is difficult to guarantee (oil prices and cannot be fuelful in time), which requires new power supply solutions to consider using solar power supply systems.
2. Reduce the battery overmail and supplement
In the power supply program planning period, it is necessary to avoid the battery capacity according to the load current, and the discharge curve of the battery is needed, and the battery is excessive is avoided during the required discharge time. The general principle is that the capacity of the battery is released when the battery discharge reaches the planning requirements.≤80%.
After the power is turned, if there is no market access or temporarily not using the battery, all loads must be disconnected, so that the battery is in an open state. Avoid battery small current discharge, resulting in a decrease in battery capacity or failure.
In terms of power storage battery management, try to avoid the battery in the warehouse for more than 3 months. If it is more than 3 months, it is necessary to consider charging the battery.
Adjust the voltage of undervoltage protection according to the actual use, try to avoid over-discharge and depth over-discharge (small current over discharge). For frequently powered off sites, in order to extend the battery life, it is required to load the lower electrical voltage at one time.≥47V, secondary lower electric voltage≥46V.
After the power is turned on, manually control execution on battery balance charging, balance charging time≥10 hours. For frequently powered off sites, you can increase the battery charging current to shorten the battery charging time and increase the amount of charge that the charging is charged. With the monitoring unit, the charging current coefficient is raised from 0.18 to 0.22c, and the maximum charge current factor cannot exceed 0.25c.
According to the number of stops of the base station, the equalization of the balanced charging time, the equalization of the equalization charging time, the original setting is generally adjusted to 30 days or 15 days, and the original setting is generally adjusted to 30 days or 15 days to reduce the phenomenon of hydrochlorination. happened.
3. Reduce high temperature effects
If the battery is installed in the computer room or the box, you need to install air conditioners to ensure that the equipment room environment is at a suitable temperature. For outdoor power, you need to build a greenhouse on the battery cabinet to avoid direct sunlight. You can put the battery in a specialized cellar by buried, ensuring that the operating environment temperature of the battery will not be too high. Outdoor power is best used in a GEL battery that is relatively wide range to reduce the effects of high temperature or low temperature on the battery to extend the service life.
4. Regular maintenance
After a period of running a period of time, the battery is behind (the battery-side voltage is not less than normal 20mV) or failure. If it is not discovered in time, then the backward battery will get backward until it is invalid. Failure battery can cause other good batteries to slowly fail, thereby enabling the entire battery. It is generally maintained for a maintenance of the battery every 3 months. It mainly checks that there is no leakage liquid in the battery pack. There is a shell deformed, there is no battery presence, and there is a rust-free and fixed screw, whether the ambient temperature is normal. . Only timely discovery timely deal with it can ensure the normal service life of the batte Recommend: LiFePO4 Battery Manufacturer Energy storage battery Manufacturer Integrated machine energy storage battery series Manufacturer Lead lithium battery Manufacturer Outdoor Backup Battery Manufacturer Portable outdoor power supply Manufacturer Power battery Manufacturer Powerwall LiFePO4 Battery Manufacturer Battery rack Manufacturers Telecom LiFePO4 Battery Manufacturer Wall mounted battery storage Manufacturer China Lifepo4 Battery
