Technical Knowledge

VRLA is the abbreviation for Valve Regulated Lead Acid, commonly known in Chinese as valve-regulated sealed lead-acid battery. It belongs to the lead-acid system, but differs from traditional open-vented batteries: under normal operating conditions the battery remains sealed, and gases generated internally recombine at the negative electrode through the absorbed glass mat (AGM), being released by the safety valve only when pressure is abnormal, thus offering maintenance-free, rechargeable, and leak-proof characteristics. As a globally leading valve-regulated lead-acid battery manufacturer, CSB markets products in more than 100 countries and regions, and its VRLA product lines are all developed on this technical route.

The core function of AGM is to allow oxygen to form channels in the separator, migrate from the positive electrode to the negative electrode, and recombine into water, with official materials stating a recombination rate of up to 99%. This mechanism reduces electrolyte loss, so the battery requires no water replenishment throughout its service life. Working in conjunction with this are a pure lead grid structure and proprietary formulation; the grid conducts electricity and supports the active material, and the pure lead system helps reduce corrosion rate, thereby supporting longer float standby life. For this reason, VRLA-AGM batteries are widely used in backup power applications requiring long-term online operation and minimal maintenance.

In electrical parameters, VRLA-AGM specifications are rated at 25°C (77°F). Taking a 12V battery as an example, the float charge voltage range is 13.5-13.8 Vdc, and the equalizing charge voltage range is 14.4-15.0 Vdc, with specific values varying by model and cell structure. Design life is likewise expressed under float standby at 25°C, covering 5 to 20 years, and some series also indicate Eurobat (20°C) classification. Regarding temperature range, nominal is 25°C, discharge is -15°C~50°C, some series can reach -25°C~50°C, and charge and storage are -15°C~40°C; these specifications directly affect capacity correction and life expectancy during selection.

In terms of product system, CSB has 142 models on sale, covering 20 series, with voltages spanning 2V cells, 6V, 12V, and 512V lithium battery cabinets, capacity types from 4.5Ah to 1700Ah, and power types from 18W to 9000W (5–15 minute rate). Among these, the VRLA-AGM series is differentiated by application: for data center UPS there are HR, HRL, XHRL, XPL, XHT, etc.; for telecommunications there are MSJ, MSV, MU, TPL, XTV, etc.; for renewable energy there are RE, XTV-WT, etc.; for general purpose there are GP, GPL; and for electric mobility there are EVX, EVH. Different series have varying emphases on terminal type, front terminal or top terminal, cycle life, and high-temperature tolerance.

Understanding the principles of VRLA-AGM helps with proper use and maintenance. Gas recombination depends on reasonable charge voltage and temperature environment; overcharging or high temperature accelerates water loss and grid corrosion, while undercharging leads to sulfation, both of which shorten actual life. Therefore, in actual projects, charging equipment should be set according to the float and equalizing charge ranges indicated in the model data, and the design life specification should be evaluated in conjunction with ambient temperature. CSB model data also indicate referenced standards such as IEC 61056, IEC 60896, IEC 60254, IEC 61427, and UL1989 Recognized, which can serve as reference for technical comparison.