Smart battery tester, also known as battery internal resistance tester or battery fast capacity tester, is a portable digital storage test instrument that can quickly and accurately measure battery health status, state of charge and connection resistance parameters. The instrument can display and record the voltage, internal resistance, capacity and other important parameters of single or multi-group batteries through online test, accurately and effectively pick out backward batteries, and can generate test reports with computer and special battery data management software to track Decay trends of batteries and provide maintenance recommendations. It is suitable for maintenance and inspection of batteries of communication base stations, substations and UPS. It is used for battery acceptance, battery matching and routine inspection.
Features
※Applicable to 2, 6, 12V batteries.
※The test speed is fast, a group of 108 battery packs only need to be tested
10 minutes
Knowledge background
A. Why do batteries (groups) need regular maintenance and testing?
In the past, open battery maintenance
It is more troublesome, because the battery needs to decompose the water in the electrolyte when it is in use, so it is necessary to regularly check the specific gravity of the electrolyte, the voltage of the battery and other parameters, and the consumed electrolyte should be replenished with water regularly. Then there are sealed batteries, mainly valve-regulated lead-acid batteries (mainly, because no need to add water, so valve-regulated lead-acid batteries are called maintenance-free batteries from the beginning, and the manufacturer promises that the The service life of the battery is 10~20 years (at least 8 years), which gives a misunderstanding to domestic technicians and maintenance personnel. It seems that this kind of battery is durable and requires no maintenance at all. There is basically no maintenance and management. Therefore, in the early 1990s, VRLA batteries used in China had many new problems that were not encountered before, such as deformation of the battery case, leakage of electrolyte, insufficient capacity, and uneven battery terminal voltage. These phenomena are not only in China, but also in foreign countries that use VRLA batteries earlier than China. In the battery, due to the larger specific gravity of the electrolyte and the larger float current, the electrode corrosion is more rapid. Electrode corrosion will also consume oxygen and thus Drying out the battery, a failure specific to VRLA batteries. Excessive gas escaping from the battery, cracks in the welded post or cover plate, poor sealing, and finally water, hydrogen and oxygen seepage through the container walls and plastic containers can all cause electrolysis Liquid leakage. Some VRLA battery failures are caused by a faulty gas regulator valve, which can dry out when the valve opens, also allows air to enter the battery, the cathode plate self-discharges, and a blocked valve can cause the cover to bulge and explode. Cooling of VRLA batteries More important than open type batteries, if insufficient thermal runaway may cause the battery to melt or explode. VRLA batteries are also more prone to corrosion and fracture due to corrosion of internal terminals, same-pole connectors, and electrode joints than open type batteries. These failures all lead to capacity loss. This makes it difficult for the user to grasp the durability and failure of VRLA batteries. Practice has proved that the terminal voltage of VRLA batteries has no correlation with the discharge capacity. During the operation of VRLA batteries and battery packs, the As the use time increases, some or some batteries will inevitably become degenerative and aging due to the increase in internal resistance. Practice has proved that the capacity of the entire battery group is based on the capacity value of the battery in the worst condition, not the capacity value of the battery in the worst condition. The average value or the rated value (initial value) shall prevail. When the actual capacity of the battery drops below 90% of its own rated capacity, the battery enters the decay period, and when the battery capacity drops below 80% of the original value, the battery enters the Rapid recession, the recession period is very short, and the battery packs are all connected in series. If there is a problem in one section, the entire battery pack will fail, and the battery pack has a great hidden danger of accidents. The user unit and the management unit , often only pay attention to the maintenance and management of the equipment part of the backup power supply, while ignoring the important role of the battery pack, but the danger of power outage is to a large extent. There are one or several aging batteries whose internal resistance increases, and their capacity will inevitably decrease. When the charger charges the battery pack, the aging battery will be fully charged due to its small capacity. The charger will mistakenly think that the entire battery pack is fully charged. Switch to float state to charge the battery pack with constant voltage and small current. The rest of the batteries in good condition cannot be fully charged. The battery pack will be charged and discharged based on the capacity of the aging battery. After several vicious cycles of floating charge - discharge - equal charge - discharge - floating charge, the capacity continues to decrease and the battery backup time is shortened. Conclusion: If you do not check regularly, find out the aging battery and adjust it, the capacity of the battery pack will become smaller, the battery life will be shortened, and the efficient and safe operation of the system will be affected. B. What problems will be encountered when using it?
Battery use problems? Electrode corrosion is more rapid: in VRLA batteries, due to the specific gravity of the electrolyte
larger and float current
Batteries dry out: Electrode corrosion can also consume oxygen and dry out batteries
?
Electrolyte leakage: Excessive gas escaping from VRLA cells, cracks in welded posts or cover plates, poor sealing, and finally water, hydrogen and oxygen seepage through vessel walls and plastic containers
? Malfunctioning gas regulating valve: valve opening can cause dry
drying out, also allows air to enter the battery, the cathode plate self-discharges, and a clogged valve can cause the lid to bulge and explode
?Battery melting
Destruction or explosion: The cooling of VRLA batteries is more important than that of open-type batteries. Corrosion of internal terminals, connecting pieces of the same polarity and electrode joints and fractures also occur more often than open-type batteries.
all of these,
will result in a loss of capacity
C. Why do you need a battery internal resistance tester?
traditional battery capacity
The detection method is to carry out the whole set of check discharge, that is, connect the battery pack to the load box, and then discharge, until the cut-off voltage (no power), to verify the capacity of the battery, but this method has many hidden dangers and shortcomings. :a. The power time is long and the risk is high. The battery pack must be disconnected from the system. The chemical energy stored in the battery pack is all consumed in the form of thermal energy, which is a waste of electric energy, time-consuming and laborious, and low efficiency. b. Certain conditions must be met for the verification discharge test. First, it should be carried out under the conditions of the basic guarantee of mains power as much as possible; secondly, there must be a spare battery pack.
C. At present, the check and discharge can only test the capacity of the entire battery group, and cannot test the capacity of each single battery
The battery with the lowest capacity is taken as the capacity of the whole group, and the deterioration or backwardness of other parts of the battery cannot be fully exposed due to insufficient discharge depth. d. Damage the capacity of the battery. Because the internal chemical reaction of the battery is not completely reversible. The number of full deep cycle discharges is limited, so it is not suitable for frequent deep discharge of lead-acid batteries. But the interval is too long, and the state of the battery between the two checks is uncertain. After the capacity of the battery drops below 80%, the battery will enter into a state of rapid decline, the decline period is very short, and it may fail a few months after the first check and discharge, and the battery pack has a huge amount of damage during the rest of the time. Accident hazard.
The principle of internal resistance test: Through a large number of experiments, it is concluded that the internal resistance value of the battery varies with the battery capacity.
The amount decreases and increases, that is to say, when the battery continues to age and the capacity continues to decrease, the internal resistance of the battery will continue to increase. Through this test result, we can conclude that by comparing the internal resistance value of the whole group of batteries or tracking the change degree of the internal resistance of the single battery, we can find out the backward batteries in the whole group, and by tracking the change degree of the internal resistance of the single battery , you can understand the aging degree of the battery, and achieve the date of maintaining the battery.
For VRLA batteries, if the internal resistance increases by more than 20% from the reference value (average value), the battery performance will drop to a lower level. This value is also the standard for which IEEE STD recommends immediate corrective action (discharge test or replacement). The IBEX1000 sets the alarm value to 20% based on this recommended benchmark.
corresponding
Yes, when the capacity of VRLA battery drops below 80%, the aging degree of the battery is like the △T in the graph. This time is unpredictable, and the speed of capacity decay will become more and more block, while the increase of internal resistance value It will also get faster. Therefore, we recommend that the battery be replaced in time to improve the reliability of your company's battery system.
So far, the practical method of judging the battery health state only uses the standards recommended by IEEE, so we suggest that when the internal resistance of the battery increases by more than 20%, corrective or replacement measures should be considered for this unit cell. The internal resistance test has the following advantages: a, small and light, online measurement. The hand-held internal resistance tester is small and portable. When testing the internal resistance of the battery, it is not necessary to remove the battery from the system, and it can be tested directly online, which will not affect the work of the power supply system and avoid the risk of the power supply system.
b. Small workload and easy operation. Internal resistance tester
The test time is generally 2-3 seconds to test a battery, and it only takes about half an hour to test a group of 200 batteries. As long as the battery is connected, the internal resistance tester will automatically test and save the data, so the operation is also very simple. C. Find outdated batteries in time. Under the circumstance that the maintenance personnel are reduced and the maintenance workload is increasing, the outdated batteries can be quickly found through the internal resistance test, which can improve the maintenance efficiency and ensure the safe and effective operation of the system. D. Can the internal resistance test completely replace the check discharge test? The check discharge method is the deep discharge of 100% C. It has the advantages of accurate and reliable capacity testing. Therefore, it is still the most reliable method for testing battery performance in the world.
Law. The check discharge method, that is, the capacity test of full discharge, is the most direct and reliable method to detect the battery capacity. Whether it is online or offline, a backup power supply must be set as a preventive measure to ensure the safety of the system.
The internal resistance test can be measured online without affecting the normal operation of the system, and the test takes time
Short, routine maintenance is very convenient. Because the internal resistance test is to check the aging degree of the battery by comparing the internal resistance difference of the whole group of batteries or tracking the internal resistance changes of the single battery in different periods, it cannot be
100% accurate measurement capacity. However, since there are many shortcomings in the verification and discharge (see knowledge background C), the internal resistance test can make up for the shortcomings of the verification and discharge detection, and through comparison to find or predict the aging battery, the daily maintenance of the battery is very convenient and effective. , and combined with the single discharge test, which greatly saves maintenance costs and makes the backup power system run more stably and safely. E. What method is used to measure internal resistance?
DC test: use the battery to discharge the test instrument to measure the voltage applied to the internal resistance of the battery
drop, and then divide it by the discharge current to get the internal resistance of the battery. The general test current is very large, reaching about 50A-80A.
Advantages: accurate test, good consistency
Disadvantages: The test current is large, and the probe must be connected to the battery.
The pole is connected stably. If the contact is not good, an arc will be generated, which will cause a safety hazard.
AC Test: Tester
The device will add an AC voltage signal of known frequency and amplitude to both ends of the battery, and measure the AC current value in the same phase as the voltage. The ratio of the AC voltage component to the AC current is the internal resistance of the battery. Advantages: The test method is simple, will not affect the working state of the battery, and will not cause safety hazards.
Disadvantages: 1. There are
Susceptible to charger ripple current and other noise sources.
2. Some devices cannot be online (connected to charge
appliance and load, and in a floating state) to test the battery. 3. It is not advisable to use AC test current with frequency of 60Hz or 50Hz, because this is the main frequency of charger ripple and noise source.
battery
quick test
