Lightweight batteries in remote-controlled aircraft may pose a fire hazard

The Consumer Product Safety Commission has issued a warning about an emerging fire hazard from the battery technology used with remote-controlled helicopters and airplanes.

In the past four months, the agency has received 26 reports of remote-controlled helicopters igniting while being charged and one report of a helicopter igniting while in flight. Minor burns and property damage were reported.

The CPSC, in an alert issued last week, said that it was concerned about the toys' rechargeable lithium batteries (lithium-ion or lithium polymer). The batteries are favored for toys because they are lighter but they pack a lot of power in a small package “so consumers should use caution when charging and handling them,” the agency said. “Overcharging them can result in overheating, fire and/or explosion.”

CPSC spokeswoman Julie Vallese added that the agency is investigating to see whether this problem is specific to remote-controlled helicopters and airplanes or is a bigger issue affecting other products as well.

Meanwhile, the agency issued a recall for one specific remote-controlled toy, the Fun2Fly Microcopter helicopter made in China, imported by Soft Air USA Inc. and sold in sporting good stores and other retailers from May 2006 through December 2007. The agency said that the rechargeable battery inside the helicopter may catch fire during charging, igniting the helicopter and nearby combustible materials. Soft Air USA has received six reports of helicopters igniting, including one minor injury. Consumers are advised to immediately stop using the recalled toy and return it to the retailer where it was purchased for a full refund.

The CPSC recommends that all users of remote-controlled toys containing rechargeable lithium batteries take the following safety precautions:

• Do not leave a toy unattended while charging it.
• Have adults do the battery charging.
• Charge the toy on a non-flammable surface and keep it away from flammable items.
• Turn off the charger when the toy’s battery is charged and always unplug it from the toy.
• Disconnect the AC wall chargers from outlets while not in use.
• If the toy has been damaged, immediately stop using it, unplug it and safely remove the toy from flammable materials.
• Follow the manufacturer’s instructions for charging the toy and do not charge the toy longer than recommended.

Comments

[Bill Potter]

I just bought a new R/C airplane, an R4U Corsair from Park Zone. On the thrid flight the aircraft started smoking and crash landed in a field. It was smoking as I approached it and I disconnected the battery wires. The foam body ignited a few seconds later and most of the fuselage and wing root were destoyed by the fire. The weeds in the field where it crashed also caught on fire and I had to kick dirt on the fire to put it out since I had no water available. I spent $300 on this plane and sent what was left of it back to the distributor of these planes.

[Al Zimmerman]

Participants of radio-controlled model forums also caution against damaging the Li-Po cells. Several posters noted severe problems (expansion, overheating) when they accidentally pierced the battery with an Exacto knife while working on the model. The recommend always removing the batteries and storing them in a safe, fire-proof container. These batteries are fun and powerful. Modern flying toys would not be possible without them. But they need more care than typical batteries.