Posts Tagged VRLA battery

Battery Technology for Data Centers and Network Rooms: Ventilation

Posted by on July 9, 2012  |  1 Comment

White Paper 34

The main objectives of any ventilation system are management of environmental air temperature, humidity and air quality. In a data center, or any facility in which electrical equipment and battery systems are installed, the ventilation system must address:

  • Health safety – the air must be free of pollutants that could be toxic, corrosive,poisonous, or carcinogenic
  • Fire safety – the system must prevent and safely remove the accumulation of gasses or aerosols that could be flammable or explosive.
  • Equipment reliability and safety – the system must provide an environment that optimizes the performance of equipment (including both batteries and electronic equipment) and maximizes their life expectancy
  • Human comfort

“Battery Technology for Data Centers and Network Rooms: Ventilation” Full White Paper (Click Here To Download)

Stationary lead-acid batteries are the most widely used method of energy reserve for information technology rooms (data centers, network rooms). Selecting and sizing ventilation for battery systems must balance and trade off many variables. These could include different battery technologies, installation methods, operating modes, and failure modes.

Executive Summary:

Lead-acid batteries are the most widely used method of energy reserve. Ventilation systems must address health and safety as well as performance of the battery and other equipment in a room. Valve regulated lead acid (VRLA) batteries and modular battery cartridges (MBC) do not require special battery rooms and are suitable for use in an office environment. Air changes designed for human occupancy normally exceed the requirements for VRLA and MBC ventilation. Vented (flooded) batteries, which release hydrogen gas continuously, require a dedicated battery room with ventilation separate from the rest of the building. This paper summarizes some of the factors and codes to consider when selecting and sizing a ventilation system for a facility in which stationary batteries are installed.

Contents:

  • Terminology
  • Environmental design considerations

Conclusion:

Ventilation systems for stationary batteries must address human health and safety, fire safety, equipment reliability/ safety, and human comfort. Vented (flooded) batteries should be installed in dedicated battery rooms, but may share the same room as the equipment they support (such as a UPS system). VRLA batteries and modular battery cartridges can be used in an office environment. The amount of heat generated by a battery system is insignificant compared to the total IT system. However, batteries need cool, clean air for optimum performance and long life. Vented batteries must have a dedicated ventilation system that exhausts to the outside and prevents circulation of air in other parts of the building. For VRLA and MBC systems, the ventilation required for human occupancy is normally sufficient to remove heat and gases that might be generated. A minimum of two room air changes per hour and a temperature in the range of 20 – 24° C (68 – 75° F) are recommended. The ventilation system must prevent the accumulation of hydrogen pockets in greater than 1 – 2% concentration.

For vented batteries, it is recommended to enlist the services of an engineering firm experienced in battery room design, including ventilation, fire protection, hazardous material reporting and disposal, and spill control.

For VLRA and MBC battery systems, the ventilation requirements for human occupancy and electronic equipment operation in a data center or network room well exceed the requirements for the batteries. No additional engineering should be necessary for VRLA battery ventilation.

White Paper Written By:

Stephen McCluer is a Senior Manager for external codes and standards at Schneider Electric. He has 30 years of experience in the power protection industry, and is a member of NFPA, ICC, IAEI, ASHRAE, The Green Grid, BICSI, and the IEEE Standards Council. He serves on a number of committees within those organizations, is a frequent speaker at industry conferences, and authors technical papers and articles on power quality topics. He served on a task group to rewrite the requirements for information technology equipment in the 2011 National Electrical Code.

Universal Networking Services’s partnership with Universal Power Group, Inc. has enabled us to build a strong distribution network of battery and related power components that meet consumer needs for accessibility, portability, security and mobility, coupled with value added offerings such as battery pack assembly and battery replacement/recycling programs.

Please feel free to contact us if you have any questions regarding this topic.

Battery Technology for Data Centers and Network Rooms: VRLA Reliability and Safety

Posted by on June 20, 2012  |  No Comments

White Paper 39

Valve regulated lead acid (VRLA) batteries have been used in UPS systems for almost 20 years. Compared to traditional flooded cell solutions, VRLA batteries allow higher power density and lower capital costs. VRLA batteries are typically deployed within power systems smaller than 500 kVA. Features of a VRLA battery include:

  • Container is sealed; liquid cannot be added or removed
  • Contains lead plates in a solution of sulfuric acid diluted in water (electrolyte)
  • Electrolyte is immobilized (not allowed to flow)
  • Operates at high currents
  • Safety vents allow escape of gas only under fault or excess charging conditions
  • Oxygen & hydrogen are recombined internally to form water
  • Installed in open frames or large cabinets (or embedded inside small power systems)

This paper will explore in greater detail some of the operating considerations of the VRLA battery. Concerns about VRLA batteries generally center on two issues: reliability and safety. Because of their wide usage (deployed at an estimated rate of 10 million units per year), many people have had experience – both good and bad – with VRLA technology. To better understand both the extent as well as the limitations of VRLA technology, we first need to understand the variations in VRLA design and the theory of operation. We can then look at the application and misapplication of this technology. All products eventually come to an end of useful life. We will explore when that should be in a VRLA battery and how that life could be lengthened or shortened according to its application and care. Although catastrophic failures are rare, we will look at what safety hazards are possible when VRLA batteries are misapplied or misused.

“Battery Technology for Data Centers and Network Rooms: VRLA Reliability and Safety” Full White Paper (Click Here To Download)

Executive Summary:

The valve regulated lead-acid (VRLA) battery is the predominant choice for small and medium sized uninterruptible power supply (UPS) energy storage. This white paper explores how the technology affects overall battery life and system reliability. It will examine the expected performance, life cycle factors, and failure mechanisms of VRLA batteries.

Contents:

  • VRLA types
  • VRLA theory of operations
  • VRLA life expectancy
  • Failure modes
  • Safety
  • Handling and environmental safety

Conclusion:

When properly applied and maintained, VRLA batteries and cartridges such as those used in small and medium-sized UPS systems can give reliable performance for three to five years or longer (depending upon battery selection). Battery dry-out is a major cause of VRLA battery end of life. Continuous monitoring and control systems can detect and respond to conditions that could cause premature cell failure. Temperature compensated and current limited charging can help prevent thermal runaway. Use of redundant, parallel strings can reduce the consequences of a cell failure and increase the life of a battery system.

VRLA batteries are safe to use in data centers and network rooms when properly applied and maintained. Neglect, abuse, or improper application can create conditions that could push a battery into failure mode. In extreme cases, catastrophic failure can cause fire and/or release of hazardous gases. Proper cooling and ventilation, regular monitoring, use of parallel strings, and temperature compensated charging can all contribute to long battery life and safety.

White Paper Written By:

Stephen McCluer is a Senior Manager for external codes and standards at Schneider Electric. He has 30 years of experience in the power protection industry, and is a member of NFPA, ICC, IAEI, ASHRAE, The Green Grid, BICSI, and the IEEE Standards Council. He serves on a number of committees within those organizations, is a frequent speaker at industry conferences, and authors technical papers and articles on power quality topics. He served on a task group to rewrite the requirements for information technology equipment in the 2011 National Electrical Code.

Universal Networking Services’s partnership with Universal Power Group, Inc. has enabled us to build a strong distribution network of battery and related power components that meet consumer needs for accessibility, portability, security and mobility, coupled with value added offerings such as battery pack assembly and battery replacement/recycling programs.

Please feel free to contact us if you have any questions regarding this topic.

Battery Technology for Data Centers and Network Rooms: Lifecycle Costs

Posted by on June 11, 2012  |  No Comments

White Paper 35

Lead-acid batteries are the predominant choice for uninterruptible power supply (UPS) energy storage for data centers and network rooms. This white paper will compare the lifecycle costs the three lead-acid battery technologies, vented (flooded, also called wet cells), valve regulated (VRLA), and modular battery cartridges (MBC). Please see White Paper 30, Battery Technologies for Data Centers and Network Rooms: Battery Options for more information about the different types of battery technologies.

Each installation is unique and results in different costs. This paper uses estimates from several different sources. While every effort was made to ensure accuracy, the examples in this paper are only a guideline and factors relating to a particular installation must be incorporated for decision-making and budgetary purposes.

“Battery Technology for Data Centers and Network Rooms: Lifecycle Costs” Full White Paper (Click To Download Here)

Executive Summary:

The lifecycle cost of different UPS battery technologies is compared. The costs associated with the purchase of batteries, the infrastructure costs, and the costs associated with inflexibility to meet changing requirements are discussed and quantified.

Contents:

  • Lifecycle Costs
  • Selection factors other than lifecycle costs

Conclusion:

This analysis finds large differences in the life-cycle costs of the different UPS battery technologies. After reviewing all three steps it is clear that a MBC battery solution can offer over 50% savings over VRLA and flooded battery solutions. Often only the battery system costs are compared and then the differences might not be compelling enough to warrant a switch from a known technology. When the infrastructure costs are added the lifecycle savings between the technologies is dramatic. This is why of the UPS sold each year world wide, over 99% use VRLA batteries or MBC. The adaptability of MBC increases the speed of deployment and can allow recovery of the 75% of cost the average data center loses due to oversizing.

Factors relating to system availability have driven some installations to deploy flooded cells despite the lower life cycle cost of VRLA or MBC batteries. The technology of the MBC battery system specifically addresses many of these issues.

When compared with flooded cell battery systems, the MBC can save over 90% in life cycle costs in a real-world situation. Most of this cost advantage results from the ability to size the battery system to the current requirement and add as needed to meet changing requirements.

In cases where the ultimate load value is pre-determined and full utilization is achieved at the first commissioning of the system, much of the advantage of the MBC battery system is lost. However, the engineering, installation, and maintenance cost advantages still provide a savings of up to 60% when compared with flooded cells.

White Paper Written By:

Stephen McCluer is a Senior Manager for external codes and standards at Schneider Electric. He has 30 years of experience in the power protection industry, and is a member of NFPA, ICC, IAEI, ASHRAE, The Green Grid, BICSI, and the IEEE Standards Council. He serves on a number of committees within those organizations, is a frequent speaker at industry conferences, and authors technical papers and articles on power quality topics. He served on a task group to rewrite the requirements for information technology equipment in the 2011 National Electrical Code.

Universal Networking Services’s partnership with Universal Power Group, Inc. has enabled us to build a strong distribution network of battery and related power components that meet consumer needs for accessibility, portability, security and mobility, coupled with value added offerings such as battery pack assembly and battery replacement/recycling programs.

Please feel free to contact us if you have any questions regarding this topic.