Intelligent CIO Africa Issue 10 | Page 71

TECH TALK 2.5 years. The temperature of the environment in which the batteries operate in is very critical to the expected life-span and performance of the battery bank. The battery banks must be installed in a clean, cool or temperature controlled environment. Discharge cycles One full discharge down to 80% depth of discharge (20% battery capacity www.intelligentcio.com remaining) and a full recharge back to 100% charged state is considered a cycle. Typical UPS deep-cycle batteries only have a cycle limit of between 200 and 500 cycles. In a situation where a power failure occurs once per month, that is 12 cycles per year, a 200-cycle rated battery would last its intended 3-5 years without any problem. However, where daily load shedding occurs, a battery would not last a year. Monitoring the number of charge and discharge cycles the battery is subjected to over a period of time is essential to understanding the expected life-span of a battery and when it should be replaced. Charge method By the very nature of its application, deep-cycle UPS batteries are usually float charged, awaiting the next discharge to take place. There could INTELLIGENTCIO 71