It is two or more electrochemical cells electrically interconnected in a appropriate series/parallel arrangement to provide the required operation voltage and current levels.

We need to address the threat of a power loss. A battery is the final defense in the event of a power failure and will allow us to maintain critical loads and start back-up generators.

A valve regulated lead acid battery is a rechargeable battery which recombines suppressed gases, thus eliminating the need to add water. They take and hold a charge very well and can hold a charge in storage for months or years at a time.

The advantages of valve regulated lead acid batteries are listed as follow: 

• The sealed construction of the battery allows trouble-free, safe operation in any position
• No special handing precautions or shipping containers - surface or air - are required due to their leak-proof construction
• Long service life under normal operating conditions
• High discharge rate due to low internal resistance, thus allows discharge current of over ten times the rated capacity of the battery
• Long service life
• Wide operating temperature range
• Deep discharge recovery as separators, advanced plate composition, and a balanced electrolyte system improved the capability of recovering from deep discharge
  

Batteries are being used in the following industries:

• Telecommunication
• Uninterruptible power system
• Security
• Military
• Power
• Railways
• Mobile

These are the two types of valve regulated lead acid battery. For efficient recombination of charge gas, valve regulated lead acid technology requires the acid electrolyte to be immobilized. The electrolyte may be gelled, or it may be absorbed into a glass mat separator (Absorbed Glass Mat).

Extreme cold dramatically reduces the speed at which chemical reaction can occur, while increasing electrolyte resistance. It is important to keep batteries at a full charge as batteries in a discharged state are susceptible to freezing, which can cause damage to the plates and battery container. 

Heat is one of the cause of battery failure. Extreme heat causes the water in the battery's electrolyte to evaporate. Heat also increases the rate of self-discharge and promotes the corrosion of the positive plate grids. 

Both of these conditions are detrimental to the long-term life of a battery.