How to Safely Charge Li-Ion Cells

Lithium-ion (Li-ion) cells and batteries are widely used in workplaces, from power tools and mobile equipment to e-bikes, e-scooters and other rechargeable devices. While they offer high energy density and convenient rechargeable power, incorrect charging, damaged cells or unsuitable equipment can create serious fire and electrical risks.

Knowing how to safely charge Li-ion cells is an important part of managing these risks and protecting workers, equipment and the workplace.

Why Is Safe Li-Ion Charging Important?

Li-ion batteries contain a large amount of stored energy in a relatively small package. If a battery is damaged, overheated, overcharged or incorrectly charged, it can potentially enter thermal runaway.

Thermal runaway is an uncontrolled chemical reaction that can cause a battery to rapidly heat up, release flammable and toxic gases, and potentially ignite. Lithium-ion battery fires can also be difficult to extinguish and may reignite after the initial fire has been controlled.

Safe charging practices are therefore essential wherever Li-ion cells or batteries are regularly charged.

1. Use the Correct Charger

Always use the charger specified or supplied by the battery or device manufacturer.

A charger that fits the connection does not necessarily mean it is electrically compatible. Using incorrect voltage or current output can damage the battery or cause overheating.

Before charging:

• Check that the charger is designed for the specific battery or device
• Follow the manufacturer's charging instructions
• Inspect the charger, cables and connections for damage
• Do not use damaged or faulty charging equipment
• Use compliant electrical equipment appropriate for the Australian market

2. Inspect Batteries Before Charging

Li-ion batteries should be inspected before they are connected to a charger.

Do not charge a battery that shows signs of damage or failure, including:

• Swelling or bulging
• Cracks, dents or punctures
• Leaking
• Unusual odours
• Excessive heat
• Discolouration
• Damaged terminals or connections
• Unusual noises

Physical damage can compromise the internal components of a battery and increase the risk of short circuits, overheating and thermal runaway. Safe Work Australia identifies physical damage, overcharging, overheating and incompatible or faulty equipment among the risks associated with Li-ion batteries.

If a battery appears damaged or defective, do not attempt to charge it. Follow your workplace's procedures for isolating and managing damaged batteries.

3. Charge Batteries in a Suitable Area

Where batteries are regularly charged at work, the charging area should be carefully considered as part of the workplace risk assessment.

Keep charging areas:

• Clear of combustible materials
• Away from heat and ignition sources
• Away from exits and emergency escape paths
• On suitable, stable surfaces
• Appropriately ventilated where required
• Protected from unauthorised access where necessary

Fire and Rescue NSW recommends charging batteries on hard, non-combustible surfaces rather than materials such as carpet, beds or upholstered furniture. Larger batteries and devices should be charged away from living areas and exits.

4. Avoid Charging Damaged or Overheated Batteries

Never attempt to charge a battery that is already unusually hot, swollen, leaking or otherwise showing signs of failure.

A battery that becomes excessively hot during charging should be treated as a warning sign. Stop the charging process if it is safe to do so and follow your workplace emergency procedures.

If a battery begins smoking, releases unusual fumes or shows signs of fire, workers should not attempt to handle or move it unless it is safe and they are trained to do so. Evacuate and follow the site's emergency response procedures.

5. Don't Leave Charging Batteries Unattended

Where practicable, charging should take place when workers are present and able to respond if something goes wrong.

Fire and Rescue NSW advises against charging batteries while sleeping or away from the property and recommends disconnecting the device once it has reached full charge.

Workplaces should establish clear procedures around:

• When batteries ca be charged
• Who is authorised to charge them
• Where charging is permitted
• What checks must be completed before charging
• What to do if a battery becomes hot or damaged
• When fully charged batteries should be disconnected

6. Keep Charging Areas Organised

Poorly organised charging areas can introduce additional risks.

Cables should be kept tidy and protected from damage, while chargers and batteries should be positioned so they cannot easily be knocked over, crushed or exposed to water.

Avoid overloading electrical outlets or power boards. Electrical equipment used in the workplace should be safe and appropriate for its environment, with electrical risks managed as part of the workplace's overall WHS system.

7. Train Workers in Safe Charging Procedures

Workers should understand the risks associated with Li-ion batteries and know what to do if something goes wrong.

Training should cover:

• Correct charging procedures
• Approved chargers and equipment
• Battery inspection
• Signs of battery damage or failure
• Safe storage
• Emergency procedures
• Reporting damaged batteries
• When batteries must be removed from service

8. Store Batteries Safely When Not in Use

Safe battery management doesn't stop when charging is complete.

Li-ion batteries should be stored in a location that protects them from physical damage, excessive heat and other conditions that could increase the risk of failure.

Where a workplace stores significant numbers of batteries, the business should assess the quantity, battery type, charging activities, storage conditions and potential fire risks when determining appropriate controls.

For workplaces with larger battery inventories, specialist storage and charging solutions may provide an additional engineering control.

Lithium-Ion Battery Charging Cabinets

A dedicated lithium-ion battery charging cabinet can provide a controlled location for charging batteries and help separate charging activities from other workplace operations.

Depending on the cabinet design and workplace requirements, features may include:

• Dedicated charging points
• Ventilation systems
• Temperature monitoring
• Fire-resistant construction
• Cable management
• Spill or containment features
• Alarm systems

The appropriate solution will depend on the type and quantity of batteries being charged, the workplace environment and the manufacturer's specifications.

What Are the Warning Signs of a Failing Li-Ion Battery?

Workers should be trained to recognise warning signs that may indicate a battery is damaged or failing.

These can include:

• Swelling or bulging
• Excessive or unexpected heat
• Strong or unusual smells
• Hissing or unusual sounds
• Smoke
• Leaking
• Discolouration
• Physical damage
• Rapid or unusual changes in charging behaviour

Titan Safety Lithium-ion cabinet solutions

As the use of lithium-ion powered equipment continues to grow, workplaces need effective procedures for charging, storing and managing batteries.

Using the correct charger, inspecting batteries before use, maintaining suitable charging areas and training workers can all help reduce the risks associated with Li-ion battery charging. For workplaces regularly charging or storing multiple batteries, additional controls such as dedicated charging and storage cabinets may also need to be considered.

Titan Safety offers a range of lithium-ion battery storage and charging solutions designed to help Australian workplaces manage battery-related risks. Explore the Titan Safety range to find a suitable solution for your workplace.