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Course 725 - Powered Industrial Truck Safety

Safety guides and audits to make your job as a safety professional easier

Forklift Maintenance (Continued)

electric forklifts

Electric Forklifts

Electric-powered forklifts are most commonly used indoors in warehouses. They produce zero emissions, virtually eliminate the hazard of carbon monoxide poisoning, and run more quietly than internal combustion forklifts. However, they present other serious hazards that must be addressed.

Recharging Electric Forklifts

Electric forklifts are powered by large lead-acid batteries, which must be routinely charged.

The hazards and recommended practices for charging and changing batteries are reviewed below. Requirements and recommended practices include:

  • Designate an area for the purpose of battery charging.
  • Make sure that the forklift is charged before using.
  • Recognize that heavy loads drain the battery more.

1. Electric forklifts are powered by _____.

a. large lead-acid batteries which must be routinely charged
b. large lead-acid batteries which must be charged at least annually
c. small lithium-acid batteries that are connected in series
d. large lithium-acid batteries that never need recharging

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The Battery Charging Area


A properly-equipped battery charging area will have:

  • a no smoking policy with signs posted
  • warning signs posted
  • adequate fire protection
  • ample and readily available water supply for flushing and neutralizing spilled electrolyte
  • an eyewash able to provide at least a 15 minute flow (Note: For large installations, there should be a plumbed drench shower and an eyewash.)
  • a phone or other means of communication in the event of an emergency
  • adequate ventilation to avoid the build-up of hydrogen gas during battery charging
  • soda ash or other neutralization materials in the immediate area
  • a dry chemical, CO2 or foam fire extinguisher
  • means to protect charging apparatus from damage from trucks

2. What should be provided in the forklift battery charging area to prevent the build-up of hydrogen gas?

a. suitable absorption material
b. a carbon filter with fan
c. adequate ventilation
d. a discharge flame to dissipate the gas

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changing batteries
This electric forklift is properly positioned while changing batteries.
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lifting beam
The battery is hoisted from forklift compartment with lifting beam.
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Battery Charging and Changing Procedures

An electric forklift is designed to operate for one shift and then be charged on the next shift or overnight. Some employers routinely change batteries instead of charging them in the vehicle. The discharged battery is removed from the forklift and a charged battery is installed in its place.

Batteries are heavy and contain sulfuric acid that is highly corrosive and could be splashed on personnel servicing or changing batteries. Toward the end of the battery charging process, batteries can give off highly explosive hydrogen gas. Contact with battery cells can cause electrical short circuits, which can burn unprotected skin.

Only trained personnel should charge and change batteries in electric forklifts. In addition to training in battery changing and charging procedures, these employees should be trained on emergency procedures in the event of an acid splash, including how to use eyewash and shower facilities.

Always follow your facility's specific safety procedures. Follow the recharger manufacturer's recommendations for attaching and removing cables and for proper operation of your equipment. Requirements and recommended practices for charging batteries include:

  • Properly position trucks and apply brakes before attempting to change or charge batteries.
  • Use a lifting beam or equivalent material handling equipment when lifting the battery. Do not use a chain with two hooks. This may cause distortion and internal damage.
  • Charge batteries in the designated battery charging area.
  • Provide an area for flushing and neutralizing spilled electrolyte, for fire protection, for protecting charging apparatus from damage by trucks, and for adequate ventilation for dispersal of fumes from gassing batteries.

3. Batteries are heavy and contain _____ and could be splashed on personnel servicing or changing batteries.

a. lithium gas that is unusually corrosive
b. sulfuric acid that is highly corrosive
c. ammonia acid that can be toxic
d. hydrogen peroxide that is highly toxic

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Battery Charging and Changing Procedures (Continued)

eyewash station
Eyewash station
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NOTE: OSHA Directive, STD 1-11.4 - 29 CFR 1910.178(g)(2); Battery Charging Stations for Fork Lifts and Other Industrial Trucks, 10/30/1978 states:

"Battery charging" areas where power industrial truck batteries are charged only--no maintenance is performed, batteries are not removed from the trucks and no electrolyte is present in the area--are not subject to the requirement of [29 CFR 1910.178(g)(2)]. The charging areas shall be in compliance with [29 CFR 1910.178(g)(1), (8), (9), (10), (11) and (12)]. Personal protective equipment shall be used when and where required.

  • When charging batteries, acid must be poured into water; water must not be poured into acid.
  • Check to assure that vent caps are functioning properly. The battery (or compartment) cover(s) should be open to dissipate heat.
  • Prohibit smoking in the charging area.
  • Take precautions to prevent open flames, sparks, or electric arcs in battery charging areas.
  • Remove all metallic jewelry before recharging. Tools and other metallic objects must be kept away from the top of uncovered batteries.
  • Wear personal protective equipment (face shield, safety goggles, neoprene or rubber gloves and apron).
  • Where the eyes or body of any person may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing of the eyes and body must be provided within the work area for immediate emergency use.
  • Check the electrolyte level before recharging. Record the specific gravity with the hydrometer in the service log. Check the pilot cell.
  • Check the water level. Do not add water prior to recharging. Record in service log.
  • Check the voltage. If the battery has sealed vents, do not recharge with a current greater than 25 amperes.
  • Unplug and turn off the charger before connecting or disconnecting the clamp connections.
  • Attach the positive clamp (+, usually colored red) to the positive terminal first and then the negative clamp (-, usually colored black) to the negative terminal, keeping the proper polarity.
  • Turn off the charger if the battery becomes hot or the electrolyte fluid comes out of the vents. Restart charging at a lower charging rate.
  • Check water level after charging. Add distilled water or de-ionized water if water level is below level indicator. Record in service log.
  • Return battery to forklift with lifting beam and secure in place after charging.
  • Check the indicator on the hour meter to see that battery is fully charged.

4. Which of the following actions is correct when charging batteries?

a. Attach the positive clamp to the positive terminal first
b. Add salt water if the water level is low
c. Check the electrolyte level after charging the battery
d. Poor water into acid. Do not poor acid into water

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Battery Maintenance

battery discharge
Discharging a battery beyond recommended levels may ruin or damage the battery.
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Under normal operating conditions, power industrial truck forklift batteries can be expected to remain in service for 2,000 work shifts or charge/discharge cycles. Implementing a proper battery maintenance program can increase the life of the batteries and help protect employees. Battery failure could lead to mechanical breakdowns and possible accidents involving forklift operators and/or other personnel.

When working with batteries, be sure to do the following:

  • Do not continue a battery in service merely because it continues to deliver power.
  • Do not exceed the service hours in the manufacturer's recommendations.
  • Do not over charge or under charge batteries.
  • Avoid discharging batteries beyond the manufacturer’s discharge level. This can result in permanent battery damage and shorten battery life considerably.
  • Warning signs of a low battery include slow starting, dim headlights, and the ammeter indicating discharge at high RPM.
  • Recycle or properly dispose of batteries. Spent batteries are a hazardous waste unless they are properly reclaimed at a lead smelter or battery recycler.
Fallsway Equipment Company on Industrial Battery Maintenance
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National Lift Truck on Industrial Battery Dos and Don'ts
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5. All of the following are warning signs of a low forklift battery, EXCEPT _____.

a. dim headlights
b. a low-temp reading on the oil gage
c. slow starting
d. high RPM ammeter show discharge

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Sulfuric Acid Splash

Water is added at the end of the charge by an operator wearing PPE.

Battery acid is diluted sulfuric acid. Sulfuric acid is a clear, colorless liquid with an acrid smell. It is corrosive and can cause severe burns, especially to the eyes. Below are requirements and recommended safe practices to prevent injuries from sulfuric acid:

  • Wear personal protective equipment.
  • Wear chemical splash goggles or full face shield with safety glasses equipped with side shields.
  • Wear acid-proof gloves made of rubber or neoprene.
  • Wear acid-resistant clothing or rubber or neoprene apron.
  • Wear acid-resistant safety shoes or boots.
  • Employees who wear contact lenses should wear chemical splash goggles during battery charging. In the event of an acid splash to the eyes, the contact lens could hold the acid to the eye, making it more difficult to flush the acid away and causing more serious damage to the eye.

6. Employees who wear contact lenses should wear _____ during battery charging.

a. chemical splash goggles
b. half-face respirator
c. glasses
d. face shield

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Emergency Procedure in the Event of an Acid Splash


These are sample procedures. Your facility may have its own safety procedure, requiring employees to contact their supervisors or medical personnel either on-site or off-site. Consult the Safety Data Sheet for additional information.

If the acid splash is to the eyes:

  • Remove safety glasses and flush eyes with clean water in eyewash for at least 15 minutes.
  • Seek medical attention immediately.
  • Report the incident to your supervisor.

If the acid splash is to the skin:

  • Remove acid soaked clothing immediately.
  • Flush acid contacted skin with clean water for at least 15 minutes.
  • Seek medical attention immediately if redness or burns occur.
  • Report the incident to your supervisor.

If the acid is swallowed and the victim is conscious:

  • Remove victim from battery area and provide fresh air.
  • Wash out mouth with large amounts of water.
  • Give victim milk to drink.
  • Do not try to induce vomiting.
  • Monitor victim's breathing and condition. Start CPR if victim stops breathing.
  • Use a NIOSH approved acid mist respirator if the OSHA Permissible Exposure Limit (PEL) of 1.0 mg/m3 is exceeded or if respiratory irritation occurs.
  • Seek immediate medical attention.
  • Report the incident to your supervisor.

If the acid is swallowed and the victim is unconscious:

  • Remove victim immediately from battery area and provide fresh air.
  • Start CPR if victim stops breathing.
  • Provide oxygen, if properly trained personnel are available.
  • Seek immediate medical attention.
  • Report the incident to your supervisor.

Sulfuric Acid Spill (In the event of battery breakage)

  • Neutralize the spill with soda ash or baking soda. Use 1 pound of baking soda to 1 gallon of water.
  • The acid reaction is complete when it stops fizzing. Make certain the acid is neutralized by checking the pH is neutral between 6 and 8.
  • Absorb neutralized material onto clay or other absorbent material, if necessary. If the spill is very large, contain the spill with earth or clay dikes.
  • Brush under the battery connectors and remove all grime. Rinse the residue from the battery with clean water with a hose.
  • Report the incident to your supervisor.
  • Determine proper disposal by contacting local environmental authorities.

7. What would you use to neutralize a sulfuric acid spill while servicing forklift batteries?

a. Sand or dirt
b. Any absorbent material
c. Soda ash or baking soda
d. A mild solution of bleach

Next Section

Hydrogen Gas

Check out this Workplace Safety North video on Industrial Lift Truck Operation.
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Flammable hydrogen gas is always present during battery recharging. Hydrogen gas is potentially explosive if allowed to accumulate in a closed area. Below are requirements and recommended best practices to prevent injuries from hydrogen gas:

  • Post no smoking signs.
  • Use non-sparking tools.
  • Prevent open flames, sparks, or electrical arcs in the battery charging area to minimize the danger of explosion.
  • Provide adequate ventilation.
  • Open the battery cover when charging so the hydrogen gas can vent better. This is especially important in confined areas where the danger of accumulation is greatest.

8. Why is it important to open the battery cover when charging forklift batteries?

a. It allows hydrogen gas venting
b. Doing so is required to prevent sulfuric acid splash
c. So you can determine water level
d. Helps prevent lithium accumulation

Next Section

Operator’s Daily Checklist: Electric Forklift

Check each item before the shift starts. Put a check in the box if the item is OK. Explain any unchecked items at the bottom and report them to a supervisor.

Forklift Serial Number:

Hour Meter Reading:



Visual Check

Tires are inflated and free of excessive wear or damage. Nuts are tight.
Forks and mast are not bent, worn, or cracked.
Load back rest extension is in place and not bent, cracked, or loose.
Overhead guard is in place and not bent, cracked, or loose.
Attachments (if equipped) operate OK and are not damaged.
Forklift body is free of excessive lint, grease, or oil.
Engine oil is full and free of leaks.
Hydraulic oil is full and free of leaks.
Radiator is full and free of leaks.
Fuel level is OK and free of leaks.
Battery connections are tight.
Covers over battery and other hazardous parts are in place and secure.
Load rating plate is present and readable.
Warning decals and operators’ manual are present and readable.
Seat belt or restraint is accessible and not damaged, oily, or dirty.
Engine runs smooth and quiet without leaks or sparks from the exhaust.
Horn works.
Turn signal (if equipped) operates smoothly.
Lights (head, tail, and warning) work and are aimed correctly.
Gauges and instruments are working.
Lift and lower operates smoothly without excess drift.
Tilt operates smoothly without excessive drift or “chatter”.
Control levers are labeled, not loose or binding and freely return to neutral.
Steering is smooth and responsive, free of excessive play.
Brakes work and function smoothly without grabbing. No fluid leaks.
Parking brake will hold the forklift on an incline.
Backup alarm (if equipped) works.

9. When inspecting the forklift, what is important to look at when checking the batteries?

a. The battery is at least 80% charged
b. Battery connections are finger tight
c. Battery covers are in place and secure
d. Corrosion on the terminals is not excessive

Check your Work

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Final Exam