Today, we re going to talk about battery safety. We ll discuss all the key issues associated with using batteries safely, including battery hazards, battery charging, and battery maintenance. Although this session focuses primarily on the lead-acid large batteries used in electric lift trucks, back-up systems, and substances, the same safety principles can be applied to smaller batteries used in cars and trucks, battery-operated cleaning and sweeping equipment, and even rechargeable power tools. 1
The main objective of this session is to make sure you work safely with batteries on the job. By the time the session is over, you should be able to: Identify battery hazards; Understand how batteries work; Charge batteries safely; Assist in maintaining batteries properly; Select appropriate PPE for battery maintenance; and Follow proper emergency procedures. 2
Before we begin the session, let s take a few minutes to see how much you already know about battery safety. Decide whether each statement on the screen is true or false. No PPE is necessary when working with batteries This is false. The only hazard of batteries is electrical shock This is also false. Vent caps should be removed during charging False again. And finally, if water or electrolyte is needed, it should be added before charging the battery This is also false. How did you do? Did you get all the answers right? If not, don t worry. You ll learn all about these issues and a lot more during the session. 3
There are four primary hazards associated with the large batteries used in lift trucks. The first hazard is battery acid. This solution is called electrolyte, and it is corrosive. It will eat holes in your clothing, etch the concrete floor of your workplace, and damage your skin and eyes. In addition, there are toxic components in the battery, and due to the sulfuric acid and lead, the unusable battery may be hazardous waste. Batteries also give off hydrogen gas. Hydrogen gas is flammable. If it s allowed to accumulate in a small area, it can easily ignite and may result in a fire or explosion. Electrical shock is another battery hazard. You ve probably connected jumper cables to your car battery and seen the sparks that jump from the battery lead to the cable as the cable is connected to the battery. Batteries are also heavy especially lift truck batteries. Attempting to handle a battery without the proper material-handling equipment can result in muscle strain or a back injury. Can you think of any other hazards of the batteries used in the workplace? 4
Before we discuss battery safety, let s talk a little bit about how a battery works. A battery consists of a number of cells. Each cell has a positive and a negative plate and can produce about 2 volts of power. Both plates are immersed in a solution of sulfuric acid and water, which, as we said in the previous slide, is called electrolyte. Each cell has its own vent cap. The vent cap is designed to allow gas to escape and to keep the electrolyte solution contained inside the battery cell. Think about the batteries you work with on the job. Can you identify each of the items listed in the slide? 5
As a battery is used, or discharges, the acid levels become weaker until the battery cannot produce an electric current. When this happens, the battery has to be charged by connecting the terminals which are connected to the positive and negative plates to an alternating current, or AC, source of electricity a battery charger. As the battery is charged by taking AC current and converting it to DC (direct) current, the acidity of the electrolyte is restored, which enables the battery to produce a current again. 6
A battery cycle consists of one discharge and one charge. Each battery can take only a limited number of charging cycles. Charging a battery for only a short period of time, such as 1 hour, will use up one of those cycles. To maximize the life of a battery, it is best to fully use, or discharge, the battery and then allow it to be fully charged. 7
Battery charging may be performed only in areas specifically designated for that purpose. In addition, remember that the charging equipment can pose an electrical hazard. Designated battery charging and storage areas need adequate ventilation to disperse any hydrogen gas generated during charging. Equipment for handling spills and neutralizing spilled electrolyte is also required in battery charging areas. In addition, fire protection equipment such as fire extinguishers is also required. You should know where to find extinguishers and how to use them in case hydrogen gas from the battery ignites. Emergency shower and eyewash stations must be located near the battery charging area in case a worker is splashed by electrolyte. Battery charging equipment must be protected from damage by forklifts with barrier poles, guardrails, or similar safety barriers. Think about the safety requirements for battery charging and storage areas and how they help protect you from battery hazards. 8
Whenever you are adding electrolyte or water to a battery, checking hydrometer readings, cleaning the battery, cleaning up electrolyte, or removing a vent cap, you must wear appropriate personal protective equipment (PPE). The PPE protects against burns from battery acid and also from electrical shock because battery acid is a conductor of electricity. The only time you don t need special PPE when working with batteries is when you are only connecting or disconnecting the batter to the charger of the lift truck. Appropriate PPE includes: Goggles designed for working with acids to protect your eyes; A face shield over the goggles to protect your face; A rubber apron to protect your body and clothing from acid; and Rubber gloves to protect your hands from the acid solution. Do you always wear appropriate PPE when required to protect against battery hazards? You should. 9
Electric lift truck batteries are very heavy, so the battery charging and storage area requires equipment that will allow an operator to remove and handle batteries safely and effectively. Before moving any battery, make sure all vent caps are in place to prevent electrolyte from spilling. An overhead hoist or crane is needed for removing some batteries. The battery will have designated pick-up points that can be connected to the hoist or crane so that the battery can be lifted out of the forklift. A conveyor with rollers may be used for removing batteries from electric lift trucks if the truck has a roller system. The battery is usually pushed on the roller conveyor onto a storage rack where it will be charged. Because battery-handling equipment could contact battery terminals or cell connectors, it must be insulated or otherwise protected to prevent electrical shocks. If you are moving a battery by hand, be sure to use the proper PPE for the job. Think about the proper procedures for handling batteries in our workplace. 10
There are five essential steps you must take when preparing to charge a lift truck battery. Before you begin, be sure to use the proper PPE. Step one, position the lift truck properly so that the battery can be removed or accessed easily for charging. Be especially cautious when maneuvering lift trucks in the charging area. Puncturing a battery or charger with a lift truck could result in electrical shock or an electrolyte spill. Step two, apply the parking break to prevent the lift truck from rolling during battery removal. If the truck rolls, it could damage equipment or the battery, or injure someone standing nearby. Step three, turn off the lights and accessories. Step four, turn off the ignition, and Step five, disconnect the battery before removing it from the lift truck. Think about these steps and any other procedures you ve been instructed to use to safely prepare for battery removal and charging. 11
When there are different kinds of batteries and chargers in use, it is very important to match the charger to the battery. Verify that the charger has the correct voltage and capacity for the battery. Chargers are designed to send the appropriate amount of charging current to the battery. If the wrong charger is used, the battery could overheat or otherwise be damaged. Cord and plug connected battery chargers must be grounded or doubleinsulated if used in a location that contains flammable materials, such as gases, solvents, and fuels. Portable battery chargers will be marked to indicate that they use an approved system of double insulation. Vent caps must be in place when batteries are being charged to prevent overflow and spilling of electrolyte. Always shut off the charger when connecting or disconnecting the battery. And finally, before charging a battery, open the battery compartment to dissipate the heat and gases generated. Think about the batteries and chargers we use in the workplace and how the charging operation should be carried out. 12
When reinstalling a battery in a lift truck, there are four basic safety steps that should always be taken. Again, remember to use proper PPE. One, avoid physical or electrical contact with compartment walls or components when reinstalling the forklift battery. Two, position the battery properly inside the forklift s battery compartment. Three, make sure the battery is secured inside the truck. Most lift trucks have some form of battery restraint system that secures the battery and keeps it in place in case of an accident such as a tipover. Four, reconnect the battery. Think about the required procedure for reinstalling batteries in lift trucks. 13
Let s take a few minutes now for a matching exercise to see if you remember the information we ve just covered. See if you can match the items in the left column with the correct matches in the right column. Let s review the matches now: A battery cycle consists of 1 discharge/1 charge; A battery hazard is flammable gas; A discharged battery has a weak acid level; A battery cell contains plus and minus plates; Charging and storage should be done in a designated area; and With battery reinstallation, the battery should be secured. How did you do? Did you make all the right matches? 14
Now it s time to ask yourself if you understand all the information about batteries and battery safety that has been presented so far. For example, do you understand what we ve said about: Battery hazards? Battery cells? Battery discharges? Battery cycle? Charging and storage locations? Battery charging procedure? It s important to understand all this information so that you can safely work with batteries. Let s continue now to the next slide and talk about battery maintenance. 15
Following the manufacturer s instructions for battery maintenance will extend the life of the battery as long as possible. One important aspect of battery maintenance is to keep connectors tight and clean. A loose or pitted connector can cause dangerous arcing or sparking. Batteries should also be kept clean and dry. If electrolyte is spilled on top of the battery, neutralize it immediately with the solution supplied in the spill kit. A normal charge can increase the temperature of a battery by 15 degrees or more. Operating hot batteries shortens their overall life, so allow them to cool down before putting them back in to service. It s also important to understand that no amount of overcharging will increase battery output beyond its rated capacity. In fact, overcharging will substantially reduce battery life. Do you know the rules for battery maintenance, including who is responsible for maintenance and how to report any battery problems? 16
Vent caps are a very important part of batteries. Each cell has a vent cap, which allows gases produced during charging to escape. While the vent cap allows gas to escape, it holds the electrolyte inside the cell so that it doesn t spill. Vent caps also protect the cell by keeping out foreign material such as dirt and debris. Make sure that all vent caps are in place and functioning properly. Remove vent caps only to add water or to take hydrometer readings. At all other times, keep them securely in place, especially during charging and cleaning. 17
A hydrometer is an instrument that measures the density, or specific gravity, of the battery s electrolyte. A fully charged battery will read 1,290, which means the electrolyte has a high acid content. A discharged battery will read 1,120, which means the electrolyte has a low acid content. After charging, check at least 2 or 3 cells with the hydrometer. If the readings are low, add more electrolyte to the cell. If the readings are fine, but the electrolyte level is low, add water to the cell. Even if you are not responsible for checking hydrometer readings, you should understand what this equipment is for and how it is used. 18
If battery cells require additional electrolyte because of low hydrometer readings or require water because of a low volume of electrolyte, remember to wear PPE and add the water or electrolyte only after charging is complete. Charging increases the electrolyte level in the cells. If water or electrolyte is added before charging, the electrolyte might overflow the cell and spill out. When handling electrolyte, use a carboy tilter or siphon designed to safely dispense electrolyte solution in order to avoid a spill. When adding water to a cell, do it slowly. Remember, the cell contains sulfuric acid solution. A reaction occurs between the water and sulfuric acid. If water is added too quickly, the reaction could cause the acid solution to bubble up and overflow the cell, or possibly spray back onto you. 19
Smoking is prohibited in battery charging and storage areas. As we mentioned earlier in the program, flammable hydrogen gas is released when batteries are charged. A cigarette could ignite the gas and cause a fire or explosion. Other precautions should also be taken in battery charging areas with: Open flames, Sparks, Electrical arcs, and Welding operations. Ventilation should always be used during charging to vent the hydrogen gas and prevent it from concentrating into a level that could be easily ignited. Do you always take proper precautions to prevent fires and explosions in battery charging areas? Your life could depend on it! 20
Tools and other metallic objects must be kept away from the tops of batteries. As we ve just said, battery gases are explosive. A tool can short circuit the battery by touching both poles at the same time. This can cause a catastrophic failure of the battery or a spontaneous release of electricity. Anyone in the area could be badly burned or killed in an explosion, depending on the concentration of hydrogen gas in the air. 21
The designated battery charging and storage area is equipped with a spill kit specifically designed for acid spills. Acid spill kits have absorbent for acid liquids and also come with acid-resistant PPE. These kits have corrosion-resistant plastic tools, such as shovels and container drums. Acid spill kits will also typically have some kind of neutralizing solution. As we said earlier, a solution of baking soda and water are commonly used to neutralize acid spills so that the spill is not as hazardous. Only attempt to clean up an acid spill if you are authorized and have received specific training in spill response and cleanup. The battery charging and storage area will also have an emergency shower and eyewash station located nearby in case of emergency. If electrolyte comes in contact with your skin or eyes, flush thoroughly with water for at least 10 minutes and then seek medical attention. Do you know how to report an emergency? You should. 22
The term battery installation typically refers to a bank of batteries used to power a specific device or used as a backup or emergency power supply during a power outage. Ventilation should always be used to prevent the accumulation of explosive gases from battery installation areas. Grounding of battery racks is also necessary to prevent static electricity that could ignite hydrogen gas in the air. 23
Now it s time for an exercise to see how much you remember about the information in the previous slides about battery maintenance. Your job is to decide if answer a or b best completes the statements on the screen. OK, let s review the correct answers. A fully charged battery will have a hydrometer reading of b, 1,290. If the hydrometer reading is low, add b, electrolyte. If the reading is OK but the electrolyte level in the cell is low, add water slowly. PPE required for battery maintenance includes b, goggles and a face shield. Other PPE includes rubber gloves and a rubber apron. Smoking in charging and storage areas is a, not allowed ever. How did you do? Did you get all the answers right? 24
Let s take a moment now to review and make sure you understand the information presented in the previous slides. For example, do you understand what we ve said about: Battery maintenance? Vent caps? Hydrometers? Adding water or electrolyte? PPE for battery maintenance? No smoking and metal tool rules? Emergency equipment and procedures? Battery installations? It s important to understand all this information so that you can safely work with batteries. 25
Here are the main points to remember about this session on battery safety: There are a variety of hazards associated with batteries, especially large lift truck batteries. Charging should be performed only in designated areas. Appropriate PPE should be worn when working with batteries. Electrolyte spills should be cleaned up immediately. If you work with or around batteries, you should know emergency procedures in case of a battery-related accident. This concludes the Battery Safety training session. 26