Best Selling VRLA Batteries
VRLA stands for Valve-Regulated Lead-Acid and is the designation for low-maintenance lead-acid rechargeable batteries. Because of their construction, VRLA/SLA batteries do not require regular addition of water to the cells.
VRLA batteries are commonly further classified as: Absorbent Glass Mat battery or Gel battery These batteries are often colloquially called sealed lead-acid batteries, but they always include a safety pressure relief valve. As opposed to vented (also called flooded) batteries, a VRLA/SLA cannot spill its electrolyte if it is inverted. Because VRLA/SLA batteries use much less electrolyte (battery acid) than traditional lead-acid batteries, they are also occasionally referred to as an "acid-starved" design.
The term "valve regulated" does not wholly describe the technology; these are really "recombinant" batteries, which means that the oxygen evolved at the positive plates will largely recombine with the hydrogen ready to evolve on the negative plates, creating water—thus preventing water loss. The valve is strictly a safety feature in case the rate of hydrogen evolution becomes dangerously high. One result of this design is a much higher ratio of power to "floor space" than large, flooded type battery systems; another is a high-rate power capacity, though of relatively short duration.
As a result, VRLA/SLA batteries are frequently employed in UPS (uninterruptible power supply) or other high-rate applications. VRLA/SLA batteries can be substituted in virtually any flooded lead-acid battery application (in conjunction with well-regulated charging), as well as applications where traditional flooded batteries cannot be used, because of their unique features and benefits.