Intelligent CIO Africa Issue 10 | Page 72

TECH TALK blocks. As most deep-cycle batteries are typically ‘maintenance-free’, as they are either sealed or semi-sealed, there is nowhere for the gases to vent. This causes a gas build-up, distorting the battery housing and permanently damaging the battery. If the battery is floated on too low a voltage, the individual cells will not be chemically stimulated correctly, can cause a reduction of capacity and internal sulphation of the cells. Ultimately the electrolyte fluid becomes less able to conduct the charge current, and eventually one will be unable to recharge the battery block. UPS systems with battery backup are the most commonly used solutions for South Africa’s power problems “Most standby batteries are performance rated at 20 0 C. For every 10 0 C that the battery operates at above the 20 0 C mark, a half-life ageing takes place.” Kevin Norris, Consulting Solutions Architect, the Jasco Group be months between discharges, which means that there is very little activity taking place within the individual battery cell chemistry. This can result in cell impedances differing slightly between each other and, as a result, cells accepting a different charge current from each other. Or, over the multiple number of battery blocks that make up a UPS battery bank, some 72 INTELLIGENTCIO battery blocks will be at a higher voltage and some at a lower voltage, which, if left unattended, could result in some battery blocks overcharging and some undercharging. In both cases, if left unmanaged, the battery block will fail during discharge, and the UPS will be unable to provide continuity of supply during critical power failure periods. On the opposite scale, if the battery bank is floated at too high a voltage for too long a period, the battery blocks will start to gas and overheat, resulting in permanent damage to the battery Proper UPS system design is critical to ensuring maximum functionality is achieved. In fact, a poorly designed system could destroy the batteries in as little as a few months, and since a battery is around half of the total cost of a UPS solution, this can be a costly error. In addition to correctly designed systems, it is also essential to ensure that batteries are proactively monitored and maintained in order to address any issues before they can become problematic. For applications where uptime is mission critical, such as for hospitals, financial institutions and security organisations, it is recommended that a permanent online monitoring solution be installed on all batteries. These solutions are self- contained, meaning they will not be influenced by other equipment, and will manage and measure all relevant aspects of the battery, proactively sending out alerts to possible failures or issues. Permanent, proactive battery monitoring solutions make use of historical data that is continuously monitored, to assess the status of the quality of the batteries in the field. By applying this methodology, one can immediately determine the risk associated with the possibility of batteries failing. This ensures that battery backup is continuously maintained at optimal levels, and will never fail without warning, preventing the potentially catastrophic consequences of such an event. n www.intelligentcio.com