September 23, 2019
You may have read reports or seen pictures online of overheated cell phones that have caught fire or exploded. When this type of event occurs, the blame typically falls on the device’s lithium-ion battery, but what role do cables play in device safety?
A lot, actually.
Power levels have been rising to meet consumer demand for faster-charging capabilities and more processing space. Historically, cables and connectors provided energy to low-power electronics, such as personal computers, keyboards and media players.
However, power level requirements changed with the development of portable computers and mobile devices. Cable assemblies shifted from powering simple, low-energy devices to new power-hungry devices.
Systems initially designed to deliver 5 volts at 500 milliamperes can now deliver voltages as high as 20 volts with currents up 5 amperes or 100 watts — enough to power a soldering iron!
It’s the rapid increase in power required to charge and power feature-packed mobile devices such as laptop computers, tablets, mobile phones power banks that have led to increasing reports of damage, smoke, or fire of connected devices.
The requirement to run a smartphone or laptop off a portable battery pack has upped the game for not only cables but device design and production as well.
Device users unaware of potential risks
Users are not typically aware of the potential risks of overheating associated with high powered devices. Inexpensive or poorly designed power and charging cables and connectors pose a potential safety risk to users and have even resulted in damage to or the destruction of some connected devices.
Improperly terminated connectors, substandard materials and cables, plus the incorrect use of electronic markers intended to help match source and load currents, all add to the growing risks associated with cable assemblies.
Related Video | Charging Safety of USB and Other High-Speed Data Cable
This applies not only to the load device of a phone but also to the charger itself where cheap construction can result in the power supply overheating and possibly igniting, presenting an extreme risk of fire.
In this scenario, the question then becomes whether the fire will be localized or propagate to potentially flammable materials such as papers on a desk, upholstery or bedding.
To keep users safe, innovate safely
With the demand for more — faster charging, more operational power and longer-lasting batteries — the cables and connectors selected for use in devices become even more critical if safety is to be top of mind. Product developers and manufacturers can innovate safely by looking to UL for help in navigating key aspects of cable design and performance.
Remember that industry specifications and safety standards play an important role in the safety of cables and connectors. Manufacturers can provide their customers with assurance regarding a product's quality and safety by following established specs and engaging in comprehensive safety assessments.
About the author
Randy Ivans is a NARTE certified product safety engineer and a program manager in UL's Wire & Cable division. His areas of responsibility include powering over LAN cable (PoE), audio/video transmission performance, patch-cord performance and ICT power cables.
Ivans is an active participant in the NFPA Research Foundation, Code-Making Panels 3 & 16, a contributing member of TIA TR42 and a Corporate Fellow in UL's William Henry Merrill Society.