Most of us have a drawer rattling with dead batteries — from the TV remote, kids' toys, smoke alarms and cordless tools. It's tempting to just chuck them in the rubbish, but batteries are one of the trickier items in the home to dispose of. When crushed in a rubbish truck or at a transfer station, they can short-circuit and start fires, and over time the metals inside — including lead, cadmium, mercury and lithium — can leach into soil and waterways. Getting battery disposal right protects waste workers, recovers valuable materials, and keeps hazardous substances out of the environment.

The first rule is simple: household batteries do not go in any of your kerbside bins. That means keeping them out of the yellow recycling bin, the red general-waste bin, and the green food-scraps bin. Loose batteries in the recycling stream are a genuine fire hazard at sorting facilities, and they contaminate otherwise good material. This applies to every common type — single-use alkaline AA, AAA, C, D and 9V batteries, rechargeable NiMH and lithium-ion packs, button cells from watches and hearing aids, and the small lithium coin cells in car keys and greeting cards.

Lithium and lithium-ion batteries deserve special care because they store a lot of energy and can ignite if damaged or if their terminals touch metal or another battery. Before storing or transporting any battery, put a strip of clear sticky tape over the terminals (the ends), or bag each battery individually. Keep your collection in a cool, dry container away from heat and out of reach of children — button cells in particular are a serious swallowing risk for little ones. If a lithium battery is swollen, hot, hissing or leaking, don't leave it indoors; place it somewhere safe like on concrete away from anything flammable and deal with it promptly.

When your container is full, take the batteries to a proper collection point rather than the bin. Many retailers offer free battery drop-off — a number of supermarkets, Bunnings, Mitre 10 and some electronics and phone stores have collection tubes or boxes near the entrance. Most council transfer stations and community recycling centres also accept household batteries, sometimes for a small fee on larger quantities. Because acceptance varies by location and battery type, it's worth a quick check of your local council website or a phone call before you drive across town.

For other battery types, use the right stewardship route. Car and other lead-acid batteries are valuable and are accepted by scrap-metal dealers, many auto shops and transfer stations — never put these in household collections. Power-tool packs, e-bike and e-scooter batteries, and laptop or phone batteries are best returned to the retailer or a dedicated e-waste service, as they're larger lithium units that need careful handling. New Zealand's battery recycling network is still growing, so options are steadily improving.

The practical takeaway is to set up a small taped-terminal battery box at home, keep it away from heat and children, and empty it at a supermarket, hardware store, transfer station or community recycling centre when it fills up. It takes only a little effort, but it prevents fires, keeps toxic metals out of landfill, and helps recover materials that can be used again. When in doubt about where to drop off a particular battery, check with your local council.