Forklift Battery Safety

A lead-acid forklift battery can be a very useful, safe source of electrical power. While installing, using, maintaining or repairing a motive power forklift battery, opportunities exist, however, for exposure to potentially dangerous situations. This section identifies those hazards which could result from improper handling or use and allows you to maintain forklift battery safety.


A sulfuric acid solution is used as the electrolyte in lead-acid batteries and has a concentration of approximately 37% by weight of sulfuric acid in water. In this diluted state it is not as hazardous as strong or concentrated sulfuric acid, but it acts as an oxidizing agent and can burn the skin or eyes and destroy clothing made of many common materials such as cotton or rayon. And given the presence of these types of batteries throughout so many industries, make sure you’re aware of industrial battery safety ahead of time.

An explosive mixture of hydrogen and oxygen is produced in a lead-acid forklift battery while it is being charged. The gases can combine explosively if a spark or flame is present to ignite them. Because hydrogen is so light, it normally rises and diffuses into the air before it can concentrate in an explosive mixture. If it accumulates into gas pockets, as can occur within a cell, it might explode if ignited. In this scenario, all manner of forklift battery safety has been breached—and harm can be done to employees and company property.

Electricity is produced by the forklift batteries on discharge and, while most persons cannot “feel” voltages below 35 to 40 volts, all motive power forklift batteries should be regarded as potentially dangerous. A lead-acid forklift battery is capable of discharging at extremely high rates and, under conditions of direct shorting, can cause a lot of damage and serious injury to a person.

The weight of these heavy forklift batteries can easily cause painful strains or can crush hands or feet if improperly lifted or handled. Forklift batteries can be damaged if dropped. The average motive power forklift battery weighs more than one ton, so proper equipment must be provided when changing or handling forklift batteries.

Burns can result from contact with molten lead or hot compound while repairing a forklift battery. Lead can splash when intercell connectors are being re-burned and hot compound can be spilled when resealing covers to jars. The protective gear provided should be worn as this will prevent such burns.


Lift forklift batteries with mechanical equipment only, such as an overhead hoist, crane or lift truck. A properly insulated lifting beam, of adequate capacity, should always be used with overhead lifting equipment. Do not use chains attached to a hoist at a single central point forming a triangle. This procedure is unsafe and could damage the steel tray.

Always wear safety shoes, safety glasses, and a hard hat made of a non-conducting material.
Tools, chains and other metallic objects will be kept away from the top of uncovered forklift batteries to prevent possible short circuits.

Forklift battery operated equipment should be properly positioned with switch off, brake set, and forklift battery unplugged when changing forklift batteries or charging them while in the equipment. This is one of the most common and easytocomplete industrial battery safety procedures that can make a world of difference.

Personnel who work around forklift batteries should not wear jewelry made from a conductive material. Metal items can short circuit a forklift battery and could cause severe burns.

Only trained and authorized personnel should be permitted to change or charge forklift batteries.

Reinstalled forklift batteries should be properly positioned and secured in the truck, tractor or crane.

Before installing a new or different forklift battery, check both the truck or tractor nameplate and battery service weight to make sure that the proper weight battery is being used. A forklift battery of the wrong weight can change the center of gravity and cause equipment to upset.


Specific areas should be designated for charging forklift batteries. These areas should be equipped with overhead hoists, conveyors or cranes for handling forklift batteries.

Charging areas should be adequately ventilated. The actual amount of ventilation will depend upon such factors as number and size of forklift batteries being charged at the same time, room size, ceiling height and air-tightness of the building. Hydrogen concentrations above 4% can be explosive.
Smoking, open flames, and sparks should all be prohibited in the charging area. Post placards “Hydrogen”, “Flammable Gas”, “No Smoking” and “No Open Flames”.

Facilities should be provided for flushing and neu- tralizing spilled electrolyte, for fire protection, including hand operated fire extinguishers, and for protecting charging equipment from damage by trucks, tractors or cranes.

Fresh water should always be available in case electrolyte is splashed on skin, clothing or into eyes. The kinds of equipment available for eye-wash and acid neutrali- zation vary widely but either an eye-wash fountain or deluge shower and chemical burn station (squeeze bottle containing a buffering solution for relief of acid burns) should be located in the immediate work area. These should be clearly identified and readily accessible.

Before connecting a forklift battery to, or disconnecting it from, a charger, the charger should be turned off. Live leads can cause arcing and pitting of forklift battery connector contact surfaces.
Make sure that all electrical connections are tight and mechanically sound to prevent any arcing or loss of power.

Wear a face shield or goggles, rubber gloves, apron and boots when checking, filling, charging or repairing forklift batteries during periods of possible exposure to acid or electrolyte.

When forklift batteries are charged on racks, the racks should be insulated to prevent any possibility of shorting.

When charging an enclosed or covered forklift battery, always keep the battery tray cover, or compartment cover, open during the charging period. This will help to keep the forklift battery cool and disperse the gases.

Keep vent caps in place at all times except while servicing or repairing cells. This minimizes the loss of electrolyte and prevents foreign matter from entering the cells.

Shut off and disconnect both input and output connections to the charger before repairing charging equipment.

When taking specific gravity readings, use a face shield or goggles and read the hydrometer with eye at about the same level as the electrolyte. Return all electrolyte to the cell.


The splashing of acid into the eyes is the most dangerous condition which can be encountered while handling sulfuric acid or electrolyte. If this should happen, the eyes should immediately be gently flooded with clean, fresh, running water for at least 15 minutes followed as quickly as possible with a physicians examination. If the person is wearing contact lenses they should be removed before rinsing the eyes.

Acid or electrolyte splashed onto the skin should be washed off under running water. Battery electrolyte will usually only cause irritation of the skin; but if a bum develops, it should be treated medically.

When electrolyte is splashed on clothing, use a weak solution of bicarbonate of soda, as soon as possible, to neutralize the acid.

A carboy tilter or safety siphon should be provided for handling acid from a carboy container. Use the protective box when moving a carboy. Store acid in a cool place out of the direct rays of the sun.

Use only glass, lead or acid resistant plastic containers when storing acid or electrolyte.

When mixing acid, to prepare electrolyte, always pour the acid slowly into the water and stir constantly to mix well. Never pour water into acid. Never use sulfuric acid solutions which are over 1.400 specific gravity.

Apply a neutralizing solution, such as bicarbonate of soda and water, when acid is spilled on floor and clean up promptly. A mixture of one pound of soda to one gallon of water is recommended. Safety Procedures While Repairing forklift Batteries

Disconnect the forklift battery from the truck, tractor or crane when servicing or repairing either the forklift battery or the equipment. Also make certain the forklift battery is disconnected from the charger before handling or repairing the forklift battery.

Before repairing a forklift battery, remove all of the vent caps and blow out each cell with a low pressure air hose to remove any residual gas. Use only a gentle stream of air to avoid splashing electrolyte

Open or “break” the circuit before repairing damaged or dirty terminal plugs or receptacles connected to a forklift battery, by removing and insulating one terminal lead at a time.

When melting sealing compound, in preparation for resealing cells, be careful not to puncture the top section of unmelted compound with a screw driver or other pointed object. A build-up of pressure from the melted compound in the bottom could cause liquid compound to squirt and inflict a severe burn. Do not allow compound to ignite by overheating. Compound becomes workable at 400 to 425 degrees F.

Check forklift batteries frequently for acid leakage or signs of corrosion.
Use insulated tools whenever possible when working on forklift batteries. If possible, also cover the terminals and connectors of a battery with a sheet of plywood or other insulating material to prevent short circuits. All these methods of forklift battery safety can effectively keep your employees and business out of harm’s way.

When taking specific gravity readings, use a face shield or goggles and read the hydrometer with eye at about the same level as the electrolyte. Return all electrolyte to the cell.