Most of us have dozens of "button" style batteries in our home. They are in many remote controls including those for your garage door opener. They are in children's talking books and in singing greeting cards. Even your bathroom scale
Batteries in children's toys can't be removed without a tiny screwdriver, but batteries in other devices come out easily. Some even fall out when the device is dropped or bumped. And they look yummy.
Unfortunately, batteries leak alkaline chemicals when they are swallowed. The new lithium batteries are more powerful and can leak more chemicals than older batteries. And the newer batteries are just big enough to get lodged in your child's esophagus where they can burn a hole right through the lining.
Don't let your child play with remote controls or any object containing button batteries. Consider purchasing electronics for adults that have child proof battery covers. Ask babysitters and relatives to keep remotes out of reach.
If your suspect your child may have swallowed a button battery, go to an emergency room immediately. The batteries start leaking almost right away and can do severe damage in just 2 hours. Oddly, alkaline chemical burns don't always hurt right away.
Symptoms of battery ingestion can include any of the following:
sudden onset crying - some children may not be in pain.
reluctance to eat
reluctance to swallow
This story from the NY Times is scary. They talk about numerous deaths caused by the newest type of button batteries.