Problems with charging electronic cigarettes caused minor fires at two Medford homes recently, Medford Fire-Rescue officials said.
Fire Marshal Greg Kleinberg said the lithium batteries used to power the nicotine vaporizers can explode if they overheat while charging.
Kleinberg said a fire in October caused by an overheating e-cig lit a mattress on fire, but the flames were quickly extinguished by a resident.
"If he didn't do that right away, it would have been a different story. It would have been a building fire instead of just a small item on fire," Kleinberg said.
On Wednesday a second e-cig exploded while being charged, sending bits of burning battery flying into the ceiling and walls, Kleinberg said. One hot piece of battery landed on a pillow, causing it to smolder and fill the home with smoke, he said.
Neither fire spread beyond the rooms where they started, but the potential for catastrophic damage was there, he said.
"Some of the batteries are failing in them or they are being overcharged," Kleinberg said. "We just wanted to put a warning out there that people need to take precautions using some of these devices.
"Just unplug it when you go to bed; make sure you have a working smoke alarm."
He said e-cig users should follow the manufacture's instructions concerning the devices.
— Sam Wheeler