Uninterruptible Power Supplies - Battery Storage and Disposal
A battery block is a self-contained, electro-chemical device that stores electrical energy for later use. The outer case is usually constructed of polypropylene PVC (which may be flame retardant) and has two protruding terminals (positive and negative). Inside, positive and negative plates are immersed in an electrolyte, typically Sulphuric Acid, to form cells with electrical potential. This is where a voltage is created and then stored when a charging current is applied.The most common type of battery used in uninterruptible power supplies is Sealed Lead-Acid but there are others: Nickel-Cadmium, for example, or Lithium Ion and Silver Alkaline.
UPS Battery Storage:
A battery will age and discharge even when not in use. The typical storage life of a battery is six to 12 months and this very much depends upon the environment in which it is stored, particularly ambient temperature. A batteryò€™s internal discharge rate will also affect its aging process. Without charge over longer periods, battery performance will reduce.
The most important factor for preserving the life of UPS batteries is temperature; the ideal is a constant 20-25 Ò°C (UPS battery life is halved for every five degrees above or below this level). To maintain temperature, a UPS and UPS battery set (particularly those running in crowded data centres) require an effective cooling system, which is a factor to be considered during uninterruptible power supply specification.
For uninterruptible power supply distributors care must be taken to monitor the actual time the UPS and batteries are left without charge as this can lead to deep discharge and potentially result in the need for a full battery set replacement.
UK and European Directives for Controlling Storage and Disposal of UPS Batteries:
ò€¢ Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC
ò€¢ EU End-of-Life (ELVò€™s) Directive (September 2000)
ò€¢ EU Batteries Directive (May 2006)
Batteries are classed as hazardous waste due to their toxic components. In essence batteries cannot simply be ò€˜thrown awayò€™ or entered into landfill. They must be disposed of in a manner that is protective of the environment and to comply with the law in most countries this should be carried out by companies licensed to perform such tasks on behalf of manufacturers (who bear the ultimate responsibility). Riello UPS is one such uninterruptible supply manufacturer that is also licensed to dispose of UPS batteries. Working with a UPS provider with ISO 14001 provides peace of mind especially if they are licensed to carry waste. They will in turn work alongside a licensed disposal company and thus ensure that they growing requirement for uninterruptible power supplies does not harm the environment.