Explore the use and maintenance of sealed lead-acid batteries

　　Author ：Iflowpower – Portable Power Station Supplier

Battery is an important part of implementing UPS uninterrupted power supply. From a large number of operating examples, due to improper use of the battery's use, it is not enough to understand the battery management functions of the UPS, resulting in a short-term use of the battery pack, which causes the capacity of the nominal capacity, resulting in the spare after the community interruption Time is shortened. Correct use, regular maintenance, and reasonable setting of the UPS battery management system, which allows the actual life of the battery to be close to the design life, and avoids unnecessary losses due to battery failure.

For sealing lead-acid batteries, the following two situations are mainly avoided during use. The first thing to pay attention to the time around the UPS and its spare battery packs should not exceed 30 ¡ã C. When the battery temperature temperature exceeds 35 ¡ã C, the "storage life" of the battery itself will be shortened due to the increase in the internal loss of the battery.

Solving the most fundamental way for battery due to overtime service life is too high, and is a precision air conditioning device to install precision air conditioning equipment in the computer room, so that the environmental operating temperature is around 25 ¡ã C. When there is no air conditioning device, a charger with temperature compensation can be used. When the ambient temperature rises, the flyback voltage value allowed by the battery will decrease.

If the floating voltage at 25 ¡ã C is also used at this time, the battery will be in a state of charge, and the battery is obviously accelerating the aging of the battery. When charging the charger with temperature compensation, the charger will follow the relationship of the charging voltage and ambient temperature in the internal preset, and then automatically adjust the charger according to the actual ambient temperature measured in the temperature sensor mounted in the battery cabinet. The floating voltage value allows the battery pack to maintain an optimal charging within a certain temperature range.

It can be seen that the charger with temperature compensation can adjust the floating voltage value with the temperature change, so that the battery pack is not in the overcharge. Thereby increasing the battery life of the battery, but it is still not possible to solve the problem of excessive environmental temperature and shortening battery actual service life. When the ambient temperature is low, although there is a wider range of charger temperature compensation, the temperature characteristics of the internal electrolyte will cause the actual capacity of the battery output.

When the ambient temperature is 0 ¡ã C, the actual capacity of the sealing lead-acid battery is about 80% of the nominal value, so when the ambient temperature is low, the temperature compensation function of the charger has a problem that the battery output capacity is lowered. It is unresolved. Sealed lead-acid batteries should pay attention to avoiding the other case where depth discharge.

The monomer discharge stop voltage value of the sealing lead-acid battery has a specific correspondence with the size of its discharge current. If the battery is discharged at a 10-hour rate, that is, the current discharges of the battery nominal capacity 1/10, the predetermined discharge voltage should stop discharge when the discharge voltage is 1.8V.

If the battery continues to discharge, the battery monomer voltage is too low. , The above over-discharge phenomenon occurs, that is, depth discharge. Sealing lead-acid battery depth discharge will inevitably reduce the number of effective cycles, shorten battery life.

If you can't make charging in time after depth discharge, you will accelerate the early failure of the battery. UPS battery management system has battery pack discharge termination voltage protection. In a battery management system with a high degree of intelligent, the battery discharge termination voltage protection point is automatically adjusted with the size of the battery pack discharge current.

This ensures that the actual protective point of the battery discharge termination voltage is higher than the discharge termination voltage protection point specified in the battery in the operating conditions of the battery pack in real time in the discharge time. This allows both the energy of the backup battery pack to be more fully utilized, and does not cause the battery to enter the depth discharge state. Since the battery pack configured by the UPS mainly considers that its rated output capacity can be maintained within 10 ~ 20 minutes after the community is interrupted.

This requires the spare battery pack to provide a large current of approximately 10 times 10 hours of discharge rate in a short time. At this time, the monomer discharge voltage of the battery pack is about 1.65 ~ 1.

70V. If the UPS is in the backup battery supply state under the setting of this discharge termination voltage value, the operator has turned off some irrelevant or completed data processing and storage device in order to extend the alternate time of the UPS, and alleviate the UPS output load. The output current of the backup battery pack is reduced.

At this time, the operator must remember to terminate the voltage value of the battery pack of the UPS battery management system. The discharge termination voltage corresponding to the discharge current can be adjusted to the discharge current according to the standard or battery manufacturer. For example, after the utility model is interrupted, when the discharge current value of the UPS load is approximately 0.

2c to 0.5c, the battery monomer discharge voltage value can be adjusted to 1.75 ~ 1.

8V according to the standard, and this voltage value can be adjusted to 1.75 ~ 1.8V according to the standard.

Take the number of alternate battery packs, which extends both the backup working time of the battery pack, and does not cause its life due to depth discharge. If the battery discharge stop voltage of the UPS is fixed, it can estimate the discharge time according to the discharge current and the predetermined termination voltage value. When the discharge time is approaching the estimation time, it is possible to turn off the UPS to avoid depth discharge from the battery pack.

The battery management system of some large and medium-sized UPSs with higher intelligence should have the function of automatic adjustment of the backup battery pack discharge termination voltage with load current. Another approach is to set the stop voltage value segment according to the length of the discharge time, the longer the discharge time, the higher the set termination voltage value, but the highest discharge termination voltage is determined in each monomer 1.80V.

Depth discharge phenomenon. The battery pack also needs to perform the necessary maintenance, and the maintenance of the spare battery is generally divided into initial maintenance before the new battery and the periodic maintenance of the battery or for a long time. After the maintenance of the new battery pack is more simple, the battery pack is connected to the UPS, the UPS can be loaded, and the backup battery pack can set the 10-hour charging current.

The ambient temperature is preferably kept at about 25 ¡ã C, according to the product manual The floating voltage value is charged for 8 ~ 10h charging. After the charging is completed, place the battery station to stand for 2h, convert the UPS to the backup battery pack, and take the appropriate amount of load to make the output current of the battery pack to 0.1C ~ 0.

2c, set the discharge termination voltage 1.8V each monomer. After a charge and discharge cycle, on the one hand, it can observe whether the charge and discharge performance of the battery pack is normal, and on the other hand, the initial capacity of the new battery can be close to its nominal capacity.

After that, the spare battery pack can be charged again, and it can be officially put into the standby state. Battery packs that start or idle with the UPS connecting machine must be maintained regularly. Regular maintenance mainly includes the following two aspects: First, discharge, charging, charging maintenance, charging maintenance.

The charge and discharge time interval is generally 6 ~ 12 months. Because the lead-acid battery does not have a memory effect, the discharged capacity does not have to be equal to the nominal capacity, and 10% to 20% of the nominal capacity can be generally released. When this discharge charging maintenance is performed on the UPS standby battery group, it is necessary to take reliable steps to ensure that the UPS load cannot be interrupted in the battery pack discharge maintenance time.

At this point, two equivalent of the same type of UPS can be used, and the output is commonly powered by the automatic conversion cabinet. Use the power-powered UPS to power the battery, and pay attention to observing the remaining capacity of the battery displayed on the UPS display, but at this time, it is not necessary to worry that because the battery pack voltage suddenly decreases, the UPS shutdown is caused, because another UPS is in the city Under the power supply, it works in a hot spare mode. Once the host is turned off, the standby is immediately put into power.

When using this discharge method, the discharge capacity of the host spare battery pack can achieve the purpose of discharge maintenance at 20% to 30%. When the load of the UPS is a general PC or the power supply inside the load has certain maintenance capability, the maintenance method of the above-mentioned backup battery pack is feasible because the switching time of the converter with the master-standing UPS mutual switching function is generally It is less than the maintenance time of load power supply. For some loads for some power maintenance time, it can be used to self-test its backup battery pack to complete periodic charging and discharge maintenance.

UPS with this advanced function does not need to disconnect the output of its internal AC / DC rectifier, but to adjust the DC output voltage of the rectifier, so that the rectifier and the backup battery pack are in parallel to power the DC / AC sine wave inverter. Adjust the output voltage of the rectifier by the detection control circuit, so that the backup battery pack is discharged at a constant current. At the same time, the UPS will display the remaining capacity of the battery pack at any time.

When this operation is performed, if the battery discharge failure causes the battery discharge failure due to a certain battery in the battery pack, it will rise to normal operation. To ensure the normal input of the sine wave inverter, make the load continuously uninterruptible power supply. This energy released by the battery self-test function is generally controlled between 10% to 20%.

Another maintenance of the spare battery pack is a balanced charging of the battery pack for a short time. This is because the battery pack is used in long-term floating backup or multiple cycles. In order to eliminate this imbalance, the monomer voltage of each battery can be charged to 2.

3 to 2.4V, and the charging current is within 0.2C, and the charging current is within 5 hours of 5 hours in this equalization.

And then transfer to normal floating state. The balanced charging maintenance of the sealed lead-acid battery should be carried out at ambient temperature of 20 ¡ã C to 25 ¡ã C, as for the battery pack to equalize the battery pack, according to the actual use of the battery pack. Generally, the voltage in the battery pack is improved after balanced charging, and the internal resistance imbalance is improved, and the life of the battery pack can be e.