This article looks at the preferred designs for battery rooms and discusses how batteries should be laid out to give a safe environment. Alternative battery stand types are discussed to illustrate accessibility of the cells or monoblocs and safety considerations.
VRLA, Vented and Nickel Cadmium battery types are included.
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Battery internal resistance and short circuit current values are available from battery manufacturers. The method used to arrive at the published values varies but when a method recognised by International Standards is used a comparison between products can be considered.
Searching the internet will reveal many papers discussing actual case studies where a battery has been shorted and interesting results have been obtained. With no fuse or battery circuit breaker in the system short circuits may result in fires and catastrophic failure. Alternatively, the protection may work and isolate the battery from the point of failure and the load resulting in loss of power to the equipment which the battery was intended to protect. It therefore follows that the subject of battery short circuit current can have at least two points of view when looked at in practical terms.
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This article discusses the manufacturing principals and processes in the manufacture of VRLA batteries. The article discusses the manufacturing processes and how deviations from the ideal can seriously affect the finished product.
The article assumes the reader has a reasonable knowledge of the construction of both AGM and GEL types. The process described here is very much simplified but will give the reader an understanding of the processes involved in manufacturing VRLA batteries.
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This article discusses the effects of storing VRLA AGM & GEL types and also vented Planté, Pasted Plate and Tubular types.
The article covers the effects of time, temperature, humidity and light and also discusses sulphation; lead dendrite growth and corrosion of the internal lead parts as well as corrosion to the pillars and UV aging of the plastic containers. The relationship between open circuit voltage and state of charge is also discussed.
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This article discusses charging of lead-acid industrial standby batteries on float charge and “off mains” locations. It does not include charging of batteries on full cycling applications such as daily traction duties or similar.
Charging of parallel battery strings, inrush currents, ripple voltage and ripple current are also discussed in outline.
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Battery back up is essential in todays world, particularly when utilised in applications such as UPS systems and emergency lighting, but how does a lead acid battery produce the power needed to keep critical building services online?
There is a lot of information available on the internet which gives detailed information of the electrochemical reactions of the lead-acid battery. It can be seen that three effective components are require; lead, lead dioxide and dilute sulphuric acid. Looking at some of the basic information shows that Faraday discovered the theoretical amounts required to produce 1 ampere-hour (Ah) of electricity are; 3.87g of spongy lead (Pb), 4.46g of lead dioxide (PbO2) and 3.66g of dilute sulphuric acid (H2SO4). However, in practice many more time the theoretical value is required to produce an effective battery.
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