Why do batteries swell?
Swelling should not be treated as a normal sign of battery ageing. In sealed lead-acid batteries in particular, high temperature, unsuitable charging conditions and internal gas formation can deform the case. A swollen battery is a sign requiring assessment of system reliability as well as capacity loss.
In UPS, rectifier, DC power and industrial battery systems, EKA System considers the operating environment and charging conditions alongside capacity. Even a correctly selected battery may fail to deliver expected performance and life under unsuitable conditions.
Why is temperature so important?
Batteries are designed for specified operating temperatures. As ambient temperature rises, electrochemical reactions accelerate. Prolonged high-temperature operation can accelerate ageing in VRLA lead-acid batteries and increase the risk of certain failure mechanisms.
Sizing a UPS or DC system therefore requires more than an ampere-hour calculation. Battery-room temperature, ventilation, charging voltage and the operating scenario must also be evaluated.
The charging system must also be checked
Replacing swollen batteries does not always remove the cause. Rectifier or charger settings, manufacturer-recommended charging voltages, ambient temperature and the condition of other battery blocks should be assessed together.
Monitoring individual block voltages is particularly important in series-connected banks. Significant voltage or temperature differences between batteries can indicate a need for more detailed investigation.
Can a swollen battery remain in use?
A physically swollen, cracked, leaking or unusually hot battery should not be treated as a routine maintenance issue. Assessment must follow the manufacturer’s safety and service instructions; intervention should wait until the necessary checks have been completed.
A battery’s appearance can be the first visible sign of a wider system problem. Regular maintenance should therefore track temperature, physical deformation and charging conditions as well as voltage and capacity.