What is a valve regulated lead acid battery?

A valve regulated lead acid (VRLA) battery is also known as sealed lead–acid (SLA) battery is a type of lead-acid battery. In this type of battery, the electrolyte that does not flood the battery but it’s rather absorbed in a plate separator or silicon is added to form a gel.

What are oxygen-recombinant valve-regulated lead-acid batteries?

Oxygen-recombinant valve-regulated lead-acid (VRLA) batteries [1,2] use the same technology as flooded lead-acid batteries, but the acid electrolyte is immobilised by sealing the battery with a valve. This eliminates the need for addition of water and avoids electrolyte mix preventing stratification.

What are valve-regulated lead-acid batteries used for?

Valve-regulated lead–acid (VRLA) batteries with the capacity of about 1−6000 Ah have been widely used in uninterrupted power supplies (UPSs), light electric scooters, and other industry applications.

What are valve-regulated lead-acid (VRLA) batteries?

Valve-regulated lead–acid (VRLA) batteries are also referred to as ‘recombinant’ batteries. Unlike flooded batteries, which lose water as a result of oxygen and hydrogen evolution at the positive and negative electrodes respectively during charging, in VRLAs, oxygen will recombine with the hydrogen to reform water .

What happens when a lead acid battery is charged?

In all lead acid batteries, when a cell discharges charge, the lead and diluted sulfuric acid undergo a chemical reaction that produces lead sulfate and water. When the battery is put on the charger, the lead sulfate and water are turned back into lead and acid. The charging current is very important for this process to take place.

What is a 'valve-regulated lead-acid' cell?

Moreover, acid is immobilized in the new design and this endows the cell with the additional advantages of being ‘spill-proof’ and able to operate in any orientation (upright, on its side, or even upside down). The change to the so-called ‘valve-regulated lead–acid’ (VRLA) technology has not, however, been accomplished without some difficulty.