What is battery deep discharge, and how is needed to prevent excessive discharge

What does the deep discharge and excessive discharge of the UPS battery mean?

Deep discharge generally refers to the discharge of about 80% of the rated capacity of the battery. UPS battery which is used of a period of time will inevitably have some active material sink, if the active material is not activated in time, is bound to cause some impact on the capacity of the battery, Therefore, it is best to carry out a deep discharge every few months to prolong battery life. However, do not discharge too deeply, or else it will damage the battery.

In UPS battery discharge process, lead dioxide and a sponge lead form small lead sulfate crystal block in a chemical reaction, after excessive discharge, lead sulfate will be formed many large crystal block, and the uneven distribution of crystal blocks, can't restore the warp in the plate, at the same time increase the plate resistance, when charging, lead sulfate crystal piece it is difficult to restore, get in the way of charging.

What are the reasons for the excessive and deep discharge of the UPS power supply battery?

Most UPS power supplies have the most efficiency at 50% to 100% load, and their efficiency drops sharply when the load is below 50%, so it is not economical when the UPS runs with excessive light load. In addition, some users always think that the lighter the load, the higher the reliability of the machine, the lower the failure rate,. In fact, this concept is not comprehensive, because the load is light enough, although it can reduce the probability of the final power pipe damaged, but it is extremely harmful to the battery. Because of excessive light load operation, once the mains power failure, if the UPS power supply battery does not have a deep discharge protection system, it may cause excessive deep battery discharge, causing permanent damage to the battery.

1. Long periods of small current discharge. As we all know, the capacity used by the UPS power supply battery is closely related to the discharge current. The smaller the discharge current, the more the actual discharge capacity is. Generally speaking, the discharge capacity of batteries must be controlled within 80% of the rated capacity. In other words, when the battery releases 80% of the rated capacity, it is not allowed to continue to discharge. If the discharge continues, it will cause a deep discharge of the UPS battery, and if the remedial measures are not taken in time, it may cause permanent damage to the battery.

2. Long periods of frequent electrical discharges. In some units and regions, due to the more frequent mainpower outage, it may cause UPS power battery frequent discharge. If after the battery discharge, there is not enough time to charge, then proceed the second time discharge immediately, by such a number of times, it may cause the deep discharge of the battery.

UPS has the minimum voltage protection value of the battery, but the end voltage of the battery is closely related to the discharge current, when the discharge current is small, the end voltage is high, and the more the actual capacity released when the minimum protection value is reached. Therefore, light load running UPS, should try to avoid discharge to the minimum protection value before the phenomenon of shutdown. The long delay UPS should appropriately increase the discharge lower limit voltage protection value.

How to prevent the damage of excessive discharge of UPS power supply battery?

The battery with a load discharge to a low power state, must be recharged within 72 hours after the battery discharge, to avoid the battery damage.

When the UPS power supply is idle, the connected battery should be disconnected, otherwise the connected UPS battery will be damaged by excessive discharge within a few days to a week, so when the UPS uninterruptible power supply is not in using, the battery and UPS power host should be disconnected;

Battery manufacturers recommend that the UPS power battery be charged immediately after discharge. The UPS power battery should be recharged within 72 hours after discharge to fully restore the capacity and service life of the battery. The voltage of each unit after battery discharge is not allowed to be lower than 1V. For a 12V battery, it is 6V.

UPS will generally be designed to alarm, when the voltage is reduced to close to the discharge termination voltage (a single section of 12 volts voltage close to 10.8 volts), it will emit an alarm sound, at this time, should immediately turn off the electrical appliances, and shut down the UPS. However, when it reachs the discharge termination voltage, it will automatically stop, to prevent over discharge;

UPS power battery require no high or low temperature, as long as the room temperature on the line, if it is too high temperature, easy to lead to battery temperature rise, damage battery performance, too low is easy to reduce the activity, and then lead to poor battery acceptance, charge and discharge times, indirectly shorten the service life of the battery.

This is the reason for the excessive discharge of the UPS power supply battery. UPS power supply should avoid short circuit discharge or excessive deep discharge, only accurate use of UPS can extend the service life of UPS power supply.