It depends on the battery type and where you live. Standard alkaline batteries (AA, AAA, C, D) can legally go in the trash in most U.S. states because they no longer contain mercury. But rechargeable batteries, lithium batteries, button cells, and car batteries should never go in your household garbage. They pose real fire and contamination risks, and in some states, trashing any battery is illegal.
Alkaline Batteries: Usually Safe to Trash
Alkaline batteries sold after May 1996 have no added mercury, which is why most states allow you to toss them in regular trash. You can identify these by a green stripe, “Hg free” label, or an expiration date later than 1998 on the packaging. If you happen to have older alkaline batteries from the mid-1990s or earlier, those may contain mercury and should go to a hazardous waste collection instead.
Alkaline batteries are also the only common household battery type that doesn’t require terminal taping before disposal. That said, recycling is still the better environmental choice. There just isn’t a widely available free recycling program for single-use alkaline batteries in most areas, which is why regulators allow them in the trash.
California Bans All Batteries in the Trash
California is the major exception. The state classifies all batteries, including ordinary alkaline ones, as universal waste. No person or business may dispose of any type of universal waste in the trash in California. You’re required to recycle them, typically through a retailer drop-off or your local household hazardous waste facility. Other states and municipalities have their own rules, so it’s worth checking with your local waste authority before assuming your regular trash is fine.
Rechargeable and Lithium Batteries: Never in the Trash
Rechargeable batteries contain metals like cadmium, nickel, cobalt, and lithium that make them hazardous waste. This includes nickel-cadmium, nickel-metal hydride, lithium-ion, and small sealed lead-acid batteries. The EPA is explicit: tape the terminals or place each battery in a separate plastic bag, and never put these in household garbage or recycling bins.
The fire risk alone makes this worth taking seriously. Lithium-ion batteries generate their own oxygen when they ignite, which means water and smothering don’t easily stop the flames. In the UK, over 1,200 battery fires broke out in garbage trucks and waste facilities in a single year. When lithium-ion batteries get crushed in a garbage truck compactor, they can short-circuit and ignite almost instantly. One fire in South London required 15 fire engines, roughly 100 firefighters, took five hours to control, and burned for four days. Some waste facility fires have caused damages reaching the equivalent of $25 million.
These aren’t rare edge cases. Surveys estimate that over a billion small electronics and nearly 450 million loose batteries were thrown in household bins in a single year in the UK alone. Every one of those lithium cells is a potential ignition source the moment it’s crushed.
Button Cell Batteries Need Special Handling
The small, round batteries found in watches, hearing aids, and greeting cards deserve extra caution for two reasons. First, some older button cells contain mercury, and even newer ones contain materials that can leach into groundwater. Second, they’re a serious child safety hazard. Button cell batteries are associated with thousands of emergency department visits every year. A swallowed button battery can burn through a child’s esophagus in as little as two hours.
As soon as you remove a button cell from a device, cover the terminals with electrical tape or place it in a sealed bag. Take it to a battery collection center rather than putting it in the trash. Keeping these batteries out of reach and out of open waste bins reduces the chance a child or pet encounters one.
What Happens When Batteries Reach a Landfill
Even when a battery is legal to throw away, that doesn’t mean it’s harmless once it’s buried. Batteries contain metals like cadmium, lead, zinc, nickel, and mercury. In landfills, these metals can slowly leach into soil and groundwater. Cadmium and mercury are the biggest concerns. Research has found that mercury levels in battery leachate can exceed accepted disposal limits, and under certain groundwater conditions, heavy metals can travel considerable distances through aquifer systems with little natural filtering.
Incineration creates a different problem. Mercury and cadmium vaporize at incinerator temperatures and can be released into the air as breathable emissions or settle into ash that itself becomes a contamination source.
How to Safely Prepare Batteries for Recycling
Before dropping off any battery for recycling, you need to prevent short circuits during storage and transport. The key step is taping the exposed terminals with clear packing tape so the battery type remains visible to recyclers. The batteries that require taping include all rechargeable types (nickel-cadmium, nickel-metal hydride, lithium-ion), lithium coin cells, small sealed lead-acid batteries, and anything over 9 volts. Nine-volt batteries are particularly prone to sparking because both terminals sit exposed on the same end.
Don’t wrap tape around the entire battery or tape multiple batteries together. Just cover the terminal contacts. If a battery is visibly leaking, swollen, or damaged, seal it in a plastic bag before handling it further.
Where to Recycle
For rechargeable batteries, Call2Recycle operates a free national recycling program with collection sites at many hardware stores, municipal recycling centers, and transfer stations. The program accepts nickel-cadmium, lithium-ion, nickel-metal hydride, small sealed lead-acid batteries, and cell phones. Many big-box home improvement stores and electronics retailers host these drop-off bins near their entrances.
Lead-acid car batteries have the most established recycling pipeline of any consumer product. The U.S. recycles 99 percent of them each year. Most auto parts stores and mechanics accept old car batteries for free, often giving you a small credit toward a replacement.
For single-use alkaline batteries, free recycling is harder to find. Some municipalities include them in household hazardous waste collection days, and a few retailers accept them, but in most areas you’ll need to pay a small fee or mail them to a recycler. In states like California where trashing them is illegal, local governments typically provide accessible drop-off locations to compensate.