You'd never leave spare change lying around within reach of a baby, toddler or little kid. But a new study says that button batteries pose an even bigger health threat to young children – and they're easily accessible inside TV remote controls and other devices.

Battery-related emergency room visits among kids reached 5,525 in 2009 – more than double the number in 1990 say researchers from the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus Ohio.

Most battery-powered kids' toys require a tiny screw driver to change the battery – an inconvenience when you're in a hurry, but a lifesaver for kids. Not so adult electronics. The study found that most ER visits were for batteries from these sources — including watches (14 percent), calculators (12 percent), flashlights (9 percent) and remote controls (6 percent). These coin-sized lithium batteries are also found in musical greeting cards, flameless candles, bathroom scales and electronic car keys.

Swallowing button batteries is risky enough. The growing use of powerful 3-volt 20-millimeter lithium batteries means kids also face increased risk for internal burns. If a battery's negative pole comes in contact with fluids in the body, such as in the esophagus, a microcurrent of electricity can generate hydroxide – burning tissue quickly. One study researcher told USA Today that complications can include fatal damage to the aorta. Once burning begins, it can continue even after the battery is removed.

You can see the effects online. Consumer Reports stuck a button battery between two pieces of moist lunchmeat to simulate what would happen in the body. Within a few days, a hole the size of a quarter had burned through the meat. "Lithium batteries can go undetected and [the swallowing of them can] be unwitnessed," Ian Jacobs, M.D., a pediatric otolaryngologist at the Children's Hospital in Philadelphia told Medscape. "Symptoms may be rather vague respiratory symptoms easily confused with other upper respiratory problems. It's very important to have a high index of suspicion when things just don't add up."

How to keep kids safe:

  • SEARCH your home, and any place your child goes, for gadgets that may contain coin lithium batteries. "They're shiny, they're small and children explore things developmentally with their mouth - if they don't know what something is, they put it in their mouth," Nicholas Slamon, MD, a pediatrician who has treated battery-related injuries at Nemours/Alfred I. DuPont Hospital for Children in Wilmington told Reuters.
  • SECURE coin lithium battery-controlled devices out of sight and reach of children. Taping a battery compartment shut may slow down a curious child, but won't stop them.
  • Lock up loose batteries. Don't leave them out or in sight.
  • SHARE this video about kids and button batteries with caregivers, friends, family members and sitters. Developed by the nonprofit group Safe Kids and battery maker Energizer, it outlines the problem graphically. Then look here for more info.

What if your child swallows one? Symptoms of coin-sized button battery ingestion may be similar to other childhood illnesses, such as coughing, drooling, and discomfort.  Kids also stick them into their nose and ears. If you think your child may have swallowed a battery, do this:

  1. Go to the emergency room immediately. Tell doctors and nurses that your child may have swallowed a battery. If possible, provide the medical team with the identification number found on the battery's package.
  2. Do not let the child eat or drink until a chest x-ray can determine if a battery is present. And don't try to make your child vomit.
  3. Call the National Battery Ingestion Hotline at 202-625-3333 for additional treatment information.