Lithium‑Ion Batteries: What You Need to Know to Stay Safe

Lithium‑ion (Li‑ion) batteries are now common in homes and businesses across New Zealand. They power everyday items like phones, laptops, power tools, e‑bikes, scooters and electric vehicles.

While Li‑ion batteries are generally safe, damage, incorrect charging or overheating can cause them to catch fire or explode. The good news is that a few simple precautions can greatly reduce the risk.

What are Li‑ion batteries?

Li‑ion batteries are rechargeable and popular because they store a lot of energy, charge efficiently and hold their power when not in use. They’re made up of multiple cells containing lithium compounds and flammable materials, protected by internal safety systems. If these cells are damaged, the battery can become a fire risk.

When can they be dangerous?

Risks can occur if a battery is:

• Overheated or overcharged

• Physically damaged

• Exposed to faulty wiring or metal objects

• Poor‑quality or incompatible chargers are used

Stop using a battery immediately if you notice overheating, leaks, unusual smells or noises, or visible changes in shape or colour. 

Simple safety tips

• Always follow the manufacturer’s instructions

• Use only the approved charger and battery

• Charge batteries on non‑flammable surfaces

• Keep batteries away from heat, water and direct sunlight

• Store and carry batteries away from metal objects

• Protect batteries from drops, impacts and sharp objects

• Install batteries correctly and avoid reversing polarity

Although Li‑ion batteries are widely used and usually safe, they do pose a fire risk. Avoid charging devices like phones in your bedroom overnight, so you’re not put at risk if something goes wrong.