On June 12th, you can drop off your hazmat (including batteries) at the Martin Luther King School between 8 am and 1 pm. The school is on the corner of Blue Hills Avenue and Westbourne Parkway. Some collections only deal with motorists, but this one allows people to walk in.
Some materials you can drop off: antifreeze, turpentine, oil-based paints, paint thinner, drain cleaner, and disinfectants. The full list is here. The hazardous waste collection only happens twice a year, so expect to wait in line.