UPS battery common maintenance skills

Engineers usually use cheap small-capacity batteries in parallel to achieve the larger battery capacity required by UPS. If multiple groups of batteries with poor performance uniformity are used in parallel, battery packs with poor performance and low voltage will have good performance. The group dragged, causing the entire UPS battery system to fail prematurely. At present, performance uniformity is mainly measured by battery voltage uniformity. There are various standard requirements in China. For example, the YD/T 799--1996 standard requirement of the Ministry of Information Industry is: 25 °C, the whole battery 2V unit float charge voltage difference is not more than ± 50mV, the open circuit voltage difference is not more than ±20mV; the power department DL/T637--1997 standard requirement is: 25 °C, if the battery system uses 2V / battery, the highest open circuit voltage and the lowest section does not exceed 30mV The 6V/cell battery does not exceed 40mV, and the 12V/cell battery does not exceed 60mV. Generally, the number of battery parallel groups should not exceed 4 groups. In order to prevent the premature failure of the whole battery system, when selecting the battery, the requirements should be made in terms of performance uniformity. When the battery model is determined, it is best to require the manufacturer to provide the same batch of battery products in a UPS system to reduce performance differences. By the same token, batteries with different brands or different degrees of old age are not recommended for mixed use due to large performance differences. Finally, it is important to point out that even if the right VRLA is chosen, some necessary routine maintenance and management is required to avoid premature battery failure.

1 UPS battery maintenance

With the continuous development of technology, the performance of UPS is getting better and better, the average trouble-free working time is getting longer and longer, and the reliability of the whole machine is getting higher and higher. It is especially important to maintain the battery of consumables in the UPS.

1.1 Initial charging of new batteries

After the new battery is installed, it is usually charged for a long time. The charging power supply should be charged according to the instructions in the manual. After the battery pack is charged, discharge is performed once, and then recharged after discharge. The purpose is to extend the battery. Service life, improve battery activity and charge and discharge characteristics.

1.2 Regular charge and discharge

The battery inside the UPS power supply is not used for a long time or the battery is in the floating state for a long time without discharging, which will cause a large amount of lead sulfate in the battery to adsorb to the cathode surface of the battery, forming a so-called "sulfation" of the battery cathode plate, due to Lead sulfate is an insulator, and its formation will have a very bad effect on the charge and discharge of the battery, because the more sulfate formed on the cathode plate, the greater the internal resistance of the battery, the more the charge and discharge performance of the battery Poor, resulting in "aging" and "activity" of the battery, greatly shortening the service life of the battery. Every 3 to 4 months, the UPS's rectifier/charger should be placed in a closed state by interrupting the mains or by software/hardware control to discharge the battery in the UPS. For such a battery discharge operation for "activating" the battery, its discharge time is preferably controlled at 1/3 to 1/4 of the normal discharge time.

1.3 Deep discharge is strictly prohibited

The service life of a sealed maintenance-free battery is closely related to the depth of discharge of the battery. The depth of discharge refers to the percentage of the number of ampere-hours discharged by the user during the use of the battery as a percentage of its nominal capacity. Deep discharge will cause the surface of the internal plate of the battery to be sulphated, resulting in an increase in the internal resistance of the battery. In severe cases, the "reverse pole" phenomenon of the individual battery and the permanent damage of the battery may occur. The depth of discharge of the battery seriously affects the service life of the battery. Do not force the battery to be in a deep discharge state.

1.4 Try to avoid overcurrent charging

Over-current charging is likely to cause the positive and negative plates inside the battery to bend, causing the active material on the surface of the plate to fall off, resulting in a decrease in the usable capacity of the battery, which may cause damage to the internal plates of the battery.

1.5 Try to avoid battery overvoltage charging

Over-voltage charging tends to cause the water contained in the battery electrolyte to be separated into hydrogen and oxygen by electrolysis, thereby shortening the battery life.

1.6 Replace the battery with reduced activity and excessive internal resistance

(1) With the extension of the UPS power supply time, the charging and discharging characteristics of some batteries will gradually deteriorate, and the terminal voltage will drop significantly. The performance of this battery cannot be solved by the internal charging circuit of the UPS power supply. There are hidden dangers and should be replaced in time.

(2) For the increase of the internal resistance of the battery, the battery that is charged with the normal charging voltage and cannot restore the charging characteristics of the battery should be replaced in time. The internal resistance of the battery is generally 10 to 30 mΩ. If the internal resistance of the battery exceeds 200 mΩ, it will not be enough to maintain the normal operation of the UPS. The battery with a large internal resistance must be replaced.

1.7 Avoid mixing old and new batteries or mixing old and new batteries

Since the internal resistance of the new battery is relatively small, and the internal resistance of the old battery has different degrees of increase, when the old and new batteries are mixed and charged together, the partial pressure will be relatively large due to the large internal resistance of the old battery, which is extremely easy. Causes over-voltage charging phenomenon; for new batteries, the internal resistance is small, the charging voltage is small but the current is too large, and it is easy to cause over-current phenomenon, so the old and new batteries should be avoided during charging and discharging.

2 Battery use environment

The service life of the battery is closely related to the ambient temperature. When the battery is at a lower temperature, the zinc plate in the battery is easily pulverized, and the storage performance is lost, causing permanent damage. When the temperature is too high, the battery capacity will also drop, which will cause permanent damage. According to the battery manufacturer's technical specifications, the optimal use temperature of the battery is 20 ~ 25 ° C, which can be used in this temperature range to extend the battery life.

Ni-Fe Battery 700~1200Ah

Nife Battery,48V 800Ah Nife Battery,Ni-Fe Battery 700~1200Ah,Ni-Fe Battery 700~1200Ah

Henan Xintaihang Power Source Co.,Ltd , https://www.taihangbattery.com