1. Do Tokyo's Used Batteries Really Travel to Hokkaido?
If you find used dry cell batteries at the back of a drawer, where do they go before they are thrown away? According to Shinjuku Ward’s information, batteries collected by local governments are recycled at the Nomura Kohsan Itomuka Mine in Kitami City, Hokkaido. There, they are separated into iron, manganese, zinc, and mercury [3].
How are they transported? A 2014 industry journal noted that 41 cooperating companies collected batteries and fluorescent lamps nationwide. These were shipped by freight train from the nearest JR container station to JR Kitami Station, then delivered to the Itomuka Mine [5]. However, since this report is from 2014, we cannot say for certain that this exact method is still used today. So, why send batteries from Tokyo to a distant factory in Hokkaido instead of processing them nearby? The hint lies inside old batteries.
2. Why Are Old Dry Cells With Mercury Collected Together With New Ones?
Dry cell batteries made in Japan up until around 1990 are the ones that contained mercury [1]. Why was mercury added? The zinc negative electrode in a battery can react on its own even when not in use, releasing hydrogen gas. This causes leaks. Mercury helped suppress this reaction [1].
Later, Japanese manufacturers released batteries without mercury. In 1991, they launched zero-mercury manganese dry cells, and in 1992, zero-mercury alkaline dry cells [2]. These dates mark when specific companies started selling them, not necessarily when the whole industry switched. Today, no mercury is used in dry cells made in Japan [2].
However, used batteries often include old ones or those made overseas. Batteries produced abroad may still contain mercury [1]. It is considered practically difficult to sort out only old or foreign-made batteries by looking at their outside appearance [1]. Therefore, dry cells are collected together. Since zinc and manganese have value as resources, collecting them for processing makes sense [1]. The difficulty in distinguishing between types leads to the current form of collection.
3. How Is Mercury Extracted From Used Batteries at the Hokkaido Factory?
Nomura Kohsan explains its recycling process by stating, “We recycle 100% of the mercury and circulate other components as much as possible.” This is the company’s own explanation [4].
To extract mercury, heat is used. The batteries are heated to about 600–800°C to turn the mercury into vapor. This vapor is collected and cooled, returning it to liquid mercury [4]. These temperatures are summarized from the company’s Q&A.
This is similar to boiling water in a kettle: steam rises, touches a cold lid, and turns back into water. However, mercury vapor is not safe like steam. This process happens only in specialized factories. Mercury that was once added to prevent leaks is now extracted to become reusable metal again. The choice to collect everything together leads to processing that does not waste mercury.
4. How Are Rechargeable Batteries Collected Differently From Dry Cells?
Rechargeable batteries follow a different path than dry cells. This includes nickel-cadmium, nickel-metal hydride, and lithium-ion batteries. In Bunkyo Ward, instructions say to insulate the battery terminals with plastic tape or similar materials. Items with a recycling mark are placed in “Small Rechargeable Battery Recycling Boxes” at cooperating stores. Collection is free [6]. Lead-acid batteries, like those used in cars, are not included.
This collection is managed by JBRC, a general incorporated association, with help from stores. Note that this describes store-based collection. Some municipalities collect them at waste stations instead, so always check your local town’s guide.
Correct disposal matters for safety. According to ITmedia, in fiscal year 2023, there were 8,543 fires attributed to lithium-ion batteries. Many of these happened because people threw them into non-combustible waste [9]. Municipal separate collection is said to reach only about 75% of households. In 2025, the Ministry of the Environment positioned lithium storage batteries as a standard separate collection category and asked municipalities to collect all household lithium-ion batteries separately [9].
5. Can Recycled Rechargeable Batteries Become Battery Material Again?
When rechargeable batteries are safely processed and crushed, they produce a black powder called “black mass.” It contains positive electrode materials with metals like lithium, nickel, and cobalt [8]. These metals come from specific countries, making resource security a challenge as demand grows. Recovering them from used batteries helps reduce the need for new mining.
DOWA Ecosystem has developed technology to recover lithium carbonate from black mass. In July 2026, they also developed a process to recover nickel and cobalt as sulfates. They have started demonstration tests aiming to sell directly to positive electrode material manufacturers [8].
Another example is “Battery-to-Battery.” Announced in October 2024, Sumitomo Metal Mining recovered copper, nickel, and cobalt from used lithium-ion batteries. From the intermediate products of this process, Kanto Denka Kogyo extracted high-purity lithium. Positive electrode materials made with this recycled lithium were confirmed to have performance equal to those made from natural resources [7]. Note that this confirmation was done at Sumitomo Metal Mining’s pilot plant. Commercial scale success is not guaranteed, but the path for batteries to become batteries again is becoming clear.
6. How Can You Check How Your Town Handles Battery Disposal?
Try checking how your town handles battery disposal. Search for “your town name + battery disposal” and open the local government page. Look for three things: Where do dry cells go? Where do rechargeable batteries go? Are they in the same place or different places? Then, think about whether your town’s method matches the “collected together” model for dry cells or the “store box” model for rechargeables.
If you have used batteries at home, do not take them apart or leave them in wet places. Check with an adult before moving them. Local pages may also list how to dispose of button batteries. If you find differences between towns, think about why they differ. This might lead to new questions.