IEEE standards recommend replacing the battery if its capacity is below 80 percent of the manufacturer’s rating. The replacement should be made as soon as these conditions are observed during testing or when identified by the monitoring system.
Depending on the skill level of in-house staff, it may be wise to have replacements performed by specialists to avoid any problems. If a battery is connected improperly following replacement, it will affect the entire string. In addition, physical characteristics, such as plate condition or abnormally high cell temperatures, should be observed. These conditions can often guide decisions on whether the complete string or an individual cell should be replaced.
Baseline resistance for the new battery or string should also be recorded. While it is common to take these measurements immediately following installation, Vertiv research shows delaying the baseline measurement for at least 90 days will provide a more accurate measurement. Resistance tends to drop following installation and then level off and a baseline measurement taken too soon after installation can be off by as much as 25 percent.
On average, baseline values for most batteries should be established after they have been in service anywhere between six and nine months. Comparing the changing features of the battery data against an accurate baseline helps identify performance patterns for better forecasting of a battery’s end of life.
Mobile DC Power Unit
Performing battery maintenance can pose a risk to operations. If the utility source drops off line or suffers a power dip while batteries are being serviced, the protection and other business-critical systems may fail to operate as intended, or the entire load may be dropped resulting in costly and potentially disastrous results.
For many critical facilities, such as chemical plants, refineries, or power plants, disabling the battery system to perform required inspections, tests, and component replacements is not an option. Having access to a temporary power solution is necessary in these situations.
Mobile power systems provide dependable, temporary power with the added convenience of timely, on-site services. By working with a service provider with a mobile DC power option, facilities are able to support and back up critical loads, ensuring no business interruptions during battery maintenance or replacement.