Battery Charging Safety

Battery charging on construction sites involves lead-acid batteries in plant and vehicles, and lithium-ion batteries in power tools.
Lead-acid batteries produce hydrogen gas during charging — a flammable, explosive gas that accumulates in unventilated areas.
Charging areas must be well ventilated, free from ignition sources, and equipped with a suitable fire extinguisher.
Battery acid (sulphuric acid) is highly corrosive — it causes severe chemical burns to skin and eyes on contact.
Eye wash stations must be available within the immediate vicinity of all lead-acid battery charging locations.
Lithium-ion batteries can undergo thermal runaway if damaged, overcharged, or exposed to heat — producing intense fire and toxic fumes.
Only chargers specified by the battery manufacturer should be used — incorrect chargers cause overcharging and fire risk.
Batteries must be inspected before charging for damage, swelling, leakage, or unusual heat that indicates internal fault.
Connecting and disconnecting charging cables must follow the correct sequence to prevent sparking near hydrogen gas.
Storage of spare batteries must be in a cool, dry, ventilated area away from combustible materials and direct sunlight.

Hydrogen explosion	Lead-acid batteries release explosive hydrogen during charging — a single spark in an unventilated area causes a devastating blast.
Thermal runaway	Damaged lithium-ion batteries undergo thermal runaway, producing intense fire and toxic gas that is almost impossible to extinguish.
Acid burns	Battery acid causes severe burns to skin and permanent blindness if splashed in the eyes — PPE and eye wash prevent this.

Do

Don't

Charge batteries in a well-ventilated area away from all ignition sources.
Ensure a suitable fire extinguisher is located at the charging station.
Inspect batteries for damage, swelling, or leakage before connecting to the charger.
Use only the manufacturer-specified charger for each battery type.
Follow the correct connection sequence: connect charger to battery, then switch on.
Wear acid-resistant gloves and safety goggles when handling lead-acid batteries.
Know the location of the nearest eye wash station when working with battery acid.
Store spare lithium-ion batteries in a cool, dry area away from combustible materials.
Disconnect batteries using the correct sequence: switch off charger, then disconnect.
Report any battery that shows signs of swelling, overheating, or unusual odour.

DON'T charge batteries in unventilated or enclosed spaces where hydrogen accumulates.
DON'T smoke, weld, or create sparks near battery charging areas.
DON'T charge batteries that are damaged, swollen, leaking, or abnormally hot.
DON'T use a charger that is not specified by the manufacturer for that battery type.
DON'T reverse the connection sequence — sparking near hydrogen gas causes explosion.
DON'T handle lead-acid batteries without acid-resistant gloves and eye protection.
DON'T work with battery acid without an eye wash station nearby and accessible.
DON'T store lithium-ion batteries near heat sources or in direct sunlight.
DON'T leave batteries on charge indefinitely without monitoring for overheating.
DON'T ignore signs of battery failure — swelling and heat indicate imminent danger.

See also: Electrical Safety Awareness | Fire Safety Awareness on Site

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