Household Recycling of Batteries (Taken from DEP site)
Description of Batteries
These should be recycled and disposed of as hazardous waste:
Nickel-cadmium rechargeable batteries (NiCads) exist in many sizes and shapes and are marked RECHARGEABLE. Some may be built into rechargeable appliances. NiCads contain cadmium, a metal that is toxic to humans when inhaled or ingested.
Button batteries (small, round, silver-colored, used in watches and hearing aids): Many button batteries contain mercury, a metal that is toxic to humans when inhaled or ingested.
Lithium batteries (AA, C, 9 volt and button; mainly used in computers and cameras). Lithium is reactive with water, and has caused serious fires.
These can be disposed of in the landfill:
Alkaline batteries (AAA, AA, C, D and 9 volt): since 1994, most types contain no added mercury, and only contain trace amounts that are not hazardous. These batteries are marked "no added mercury" or have a green tree logo.
Alkaline batteries: Domestically manufactured batteries made after 1994 no longer contain mercury and can be disposed of in the trash.