Recently, the National Offshore Petroleum Safety and Environmental Management Authority was notified of a fire that occurred in the battery room on a production facility. The incident was likely caused by leaking electrolyte fluid contacting a conductive metal cabinet frame in the UPS battery room.
The incident highlighted the potential for thermal runaway events, specifically, when there is a short circuit between two or more battery banks of uninterruptible power supply (UPS).
Lead acid batteries are capable of delivering an electric charge at a very high rate. When charging the batteries can release flammable hydrogen gas which, when combined with oxygen, has the potential to cause an explosion.
Under certain circumstances, such as short circuit faults, energy may be rapidly released increasing the heat load, potentially causing an ignition of gases & explosion around the battery.
Even ‘maintenance free’ valve regulated batteries may release hydrogen through the pressure relief valves if the battery charging current or voltage is exceeded, which can also potentially result in explosion.
Battery installations, stands or trays need to be designed to eliminate or reduce the risk of faulty currents associated with battery terminals or short circuits. Battery stands or trays need to be insulated and access to battery terminals, inspection caps, or charge indicators should be sufficient to allow effective safe, maintenance.
The facility’s performance standards need to clearly identify the operational performance required for the battery systems and batteries checked for replacement d before they reach their end of life condition.
As a credible event, battery fire needs to be included in emergency response planning, procedures and drills.
Working safely in battery rooms