Batteries contain volatile, and therefore potentially, hazardous materials which can cause burns and other serious injuries. Photo Credit: Wikimedia
Batteries are used extensively across the power grid to ensure that critical electrical equipment is always on. Without battery backup, many of the services that we take for granted would fail leading to incalculable damage.
Performing regular inspections on battery systems presents a unique challenge from other electrical power systems in that you cannot simply turn them off for maintenance or corrective action.
Batteries are safe when operated and handled properly. However, they do contain volatile, and therefore potentially, hazardous materials which can cause burns and other serious injuries. Only a qualified individual who is knowledgeable in batteries and the required precautions should perform servicing of the batteries.
Observing these four precautions can help avoid danger and injury when handling or working with batteries:
The sulfuric acid in a battery is corrosive and can severely burn the skin or eyes, eat through clothing or even a concrete floor. Appropriate personal protective equipment (PPE) is essential when working on batteries or any UPS equipment. Protect yourself by using these four pieces of PPE:
Goggles: Eyes need protection from acid splashes and fumes.
Face shield: Skin on the face and neck needs protection from electrolyte as well.
Rubber Gloves: Provides both acid protection and electrical resistance to prevent shocks.
Rubber Apron: Clothes and the body require the same protection as the eyes, face and hands.
Have an emergency kit nearby with corrosion-resistant plastic tools and materials to absorb acid. Baking soda is commonly used to neutralize electrolyte spills. You should always refer to the material safety data sheet for specific precautionary measures.
Keep emergency shower and eyewash stations within 25 feet of battery handling areas. Photo Credit: Wikimedia Commons.
Keep emergency shower and eyewash stations within 25 feet of battery handling areas in case of contact with a worker’s skin or eyes, rinse immediately for at least 10 minutes and then seek medical attention.
Batteries emit flammable hydrogen gas, especially during charge and discharge cycles. Hydrogen ignites easily and can cause a fire or explosion if allowed to accumulate in a small area.
Hydrogen is not toxic, but at high concentrations is a highly explosive gas. The 100% LEL concentration for hydrogen is 4.0% by volume.
At this concentration, all it takes is a source of ignition to cause an explosion. Sparking from a battery terminal as it is connected or disconnected from the charging system is more than adequate as a source of ignition energy.
Hydrogen ignites easily and can cause a fire or explosion if allowed to accumulate in a small area.
Adequate ventilation should be in place to disperse fumes given off during charging. Clearly designate areas as “No Smoking” and eliminate the risk of open flames, sparks, welding and electric arcs.
Each cell has its own vent cap, designed to allow gases to escape and keep the electrolyte solution from spilling. Check that vent caps are in place to prevent overflow and spilling of dangerous acid.
Fire protection equipment, such as fire extinguishers, should be stored in an easily accessible location nearby. All qualified workers should know how to operate fire extinguishers.
Batteries are stored energy devices, meaning no overload protection is available if the battery is connected improperly or short-circuited. Always keep a voltmeter handy to verify correct polarity and expected voltage levels when connecting strings of batteries.
Exercise caution when working with metallic tools or conductors to prevent short circuits and sparks. Remove rings, watches and loose jewelry when working with batteries. Never lay tools or other metal parts on top of a battery.
Cells used in large industrial standby-power applications can weigh anywhere from 20 to 100+ pounds apiece. When combined into large battery banks, weights can exceed into the thousands of pounds.
Battery banks used in large industrial standby-power applications can weigh thousands of pounds. Photo Credit: Wikimedia.
Use safe lifting techniques while exercising caution of electric shock as discussed above. Work in teams, always lifting with your legs, and use a forklift or similar device when lifting heavy loads. Do not attempt to stop a battery if it slides out of the equipment.