Batteries are used as power sources for electronics, vehicles, tools, industrial equipment, homes and businesses. Electrical workers play a major role in maintaining and repairing the electrical components and systems within them. However,
working with batteries can present some unique and significant hazards. It is necessary to be aware of how batteries work and what dangers they pose so workers can adopt basic safety protocols to mitigate hazards.
A battery accepts, stores and releases electricity on demand. According to the Department of Energy Office of Energy Efficiency and Renewable Energy, “For batteries to work, electricity must be converted into a chemical potential form before it can be readily stored. Batteries consist of two electrical terminals called the cathode and the anode, separated by a chemical material called an electrolyte. To accept and release energy, a battery is coupled to an external circuit. Electrons move through the circuit, while simultaneously ions move through the electrolyte.”
Types of batteries
There are three common types of industrial batteries: nickel cadmium, lithium-ion (Li-ion) and lead-acid. Nickel cadmium batteries were commonly used in the 1980s but are now only used in aircraft, backup power for telecommunications networks and mass transit. Li-ion batteries are used in electric vehicles, smartphones, laptops, power tools and grid energy storage.
With the major increase in Li-ion batteries over the last decade, there are several dangers to consider. According to the American Chemistry Society, “Hazards for Li-ion batteries can vary with the size and volume of the battery. Li-ion batteries are prone to overheating, swelling, electrolyte leakage venting, fires, smoke, and explosions in worse case scenarios involving thermal runaway. The gases produced as a result can accumulate to a combustible level and cause an explosion. The most common electrical hazards are overcharge, over-discharge, and external and internal short circuits.”
There are two types of lead-acid batteries: starting, lighting, ignition (SLI) and deep cycle. SLI batteries are typically used in cars and trucks. Deep cycle batteries power machines such as golf carts and forklifts. Lead-acid batteries contain sulfuric acid that is extremely toxic and corrosive, which can result in irritation and burns when in contact with the skin. If it gets in the eyes, it can burn the cornea and cause permanent blindness.
As a result, the Occupational Safety and Health Administration requires eye-wash stations within 25 feet of a location where a battery is being worked on. If acid does come in contact with the skin, workers should wash the area with soap and water and avoid contact with the eyes.
Regardless of type, the risks of improperly handled or maintained batteries include electric shock, chemical leaks and even explosions. When working on batteries, workers should isolate battery power sources and make sure there is proper ventilation in storage and work areas. This will help to prevent exposure to harmful gases. Workers should also avoid using metal tools when working on live battery connections. This will prevent short circuits and electric shock.
When working with any hazardous energy, the appropriate lockout/tagout procedures must be followed. With batteries, this means identifying the energy source or sources supplying power to the battery system; isolating and locking out each energy source to prevent accidental activation; placing visible tags indicating the system is under maintenance to alert others to avoid energizing it; and verifying that the system is de-energized and safe to work on prior to initiating tasks.
Electrical workers should adhere to NFPA 70E, Standard for Electrical Safety in the Workplace, guidelines.
The appropriate personal protective equipment should also be worn and used properly. This may include safety glasses/eye protection, insulated gloves, flame-resistant clothing and footwear with electrical protection. PPE can safeguard against potential electrical, chemical and thermal hazards.
Risks from charging
Charging batteries can also pose some significant risks such as fire and explosion due to thermal runaway. It is imperative to only use approved chargers designed for the specific battery type, inspect charging equipment for damage or malfunction, make sure charging areas are well-ventilated and free from flammable materials and ensure batteries are stored at or below recommended temperatures to prevent overheating. Additionally, it is important to avoid overcharging batteries, which can lead to excessive heat generation.
Electrical contracting firms should prepare an emergency plan. Knowing where and how to use emergency shut-off switches and having the appropriate fire extinguishers on hand can be extremely helpful in minimizing an emergency.
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