A battery is an electricity storage device which can be found in any number of shapes, size, voltage and capacities.
When two conducting materials (often dissimilar metals) are immersed in a solution, an electrical potential will exist between them is connected together through a closed circuit, a current will flow. The value of this potential (or voltage) is dependent on the materials used, giving rise to a whole family of battery types each having benefits and restrictions in use. Examples are: - lead acid, nickel cadmium ( NiCad ), lithium, silver alkaline.
This manual is concerned only with one battery technology ?C the most successful ?C lead acid (lead and lead oxide immersed in sulphuric acid). Each cell has a 2 volt potential.
A battery is simply a number of cells connected together with a given voltage and capacity. The more cells the higher the voltage, the large the plates the higher the capacity (in general).
Purely for convenience, batteries are made in 12 volt blocks with 6 cells but are also available in 6 volt, 4 volt and even 2 volt, single cell blocks.
Batteries can be connected in series to achieve whatever voltage is required (add the number of 2 volt cells) and in parallel to achieve the capacity required (add the capacities of each parallel battery or string of batteries) . For larger systems, a number of series connected strings maybe connected in parallel with each other. This achieves both a higher voltage and capacity.
The Lead-acid Battery
There are two concepts in lead-acid batteries and three basic applications.
Three Basic Applications
1. Sealed or Regulated Lead Acid VRAL
2. Automotive (starter i.e. Cars, commercial vehicles)
3. Traction (Electric motor drive i.e. milk float)
CAUTION: ALWAYS USE A BATTERY BEST DESIGNED FOR THE APPLICATION.
This guide is focused on Industrial Standby applications and NOT Automotive or Traction use.
Industrial batteries are available from two distinct groups with the following features. Note: VRLA have superseded open-vented in many applications
|1. Older technology
2. Require separated battery room
3. Regular routine maintenance
4. Separate safety requirements
5. Store/use in vertical position
6. Can require extensive cabling
|1. Environmentally friendly|
2. Use directly in office environment
3. Low maintenance-"maintenance free"
4. Self-contained. Safe
5. Store/use in any orientation
6. Can be used internal or adjacent to load
|VRLA has in many instances replaced the open-vented type.|
Note: The term sealed lead-acid SLA is an old acronym Considered misleading and is now replaced by Valve Regulated Lead Acid VRLA.