USB cable durability; cost and confusion?
When we purchase low cost USB cable products, it may appear that we’re getting a bargain but is all what it seems?
How many of us simply look at the cable connector and think “it’ll fit, so it should be fine”, but then have a little doubt in the back of our mind about buying the lowest cost product so opt for something just a little bit better with the belief that we’re then getting a higher quality, more durable product? Does this approach really work, do the products even show the durability specifications and would you even know how to decode the data if you can get it?
Unfortunately, this is a grey area for consumers often due to undefined product specifications so we tend to rely on the product and packaging logos to determine the safety and durability of a product but this also has limitations.
The main logos we may expect to see in Europe are CE safety compliance and USB-IF logos;
Many manufacturers still treat USB cables as components of a system rather than products without understanding that these are still included in the ‘Low Voltage Directive’ and therefore require CE Marking under this directive. So, the first issue is whether the product has CE compliance, and secondly whether this is accurate? Previous EU studies have shown that 24% of USB cables that had CE marking failed ROHS compliance. This has given rise to the EU increasing market surveillance and enforcement activities to ensure the manufacturer follows all CE safety rules which now places responsibilities on the importer and distributor regarding product distribution. Whilst this should ensure that only 'safe' product is available in future, there is still a great deal of dubious quality product on the market mostly available via e-commerce platforms with no safety compliance logo so consumers have to look elsewhere for product quality assurance until such times as market surveillance activities remove such product.
The USB-IF defines the standards for USB cables and connectors and Apple provides similar under MFi for the USB - Lightning cables. These standards do include some durability testing for the cable assembly and the trademark protected USB or MFi logos can only be used when a product has passed the specified compliance testing for product quality. So, if a product uses the USB or MFi logo then it should be durable right? Well, not necessarily as the standards are based on a typical usage model which may not be representative of a true use-case, especially if the cable is being frequently used. For example, the USB-IF specifies the Type C cable flex/bend test in EIA 364-41. Unfortunately, this only specifies 100 bend cycles which is often not representative or real world usage conditions. The specification is illustrated below;
Whilst manufacturers can design a product to far exceed this requirement for a more durable product, this can also be misleading without the full test specification so what does a bend test number really mean without knowing bend arc or axial loading? This extra durability also results in a higher cost product so how can those features be easily and fully promoted to consumers to justify the extra cost and will consumers be willing to pay the extra when comparing against a lower cost product of undefined or lower quality?
With limited information available, it therefore appears that product cost is the primary factor that influences buying behaviour with quality concerns primarily addressed through purchasing feedback. Regrettably, we now know that many platforms can unwittingly host fake reviews so perhaps ‘no news is good news’? Unfortunately, the sad truth is that ‘low cost’ invariably means ‘cheap’ (definition; “Inexpensive because of inferior quality”) and the old adage that ‘you get what you pay for’ still applies regarding cable durability regardless of brand.
To prove this, we purchased the top 18 CE approved cables (by sales volume) from a popular e-commerce channel covering USB-Micro and USB-C connector categories and tested them ourselves. However, we used a tougher test, more representative of real world usage conditions to test the effectiveness of the connector strain relief which is where the connector usually fails. The test consisted of applying a small load to one end of the cable, then bending the cord at 30 cycles/minute with the angles of 120° (from 60° either side of central ) for 10000 cycles as defined by many consumer electronics brands, before rechecking that the electrical properties were still compliant to the USB-IF specifications for charging current and signal integrity. We then rechecked for the connector on the other end of the cable. It should come as no surprise that most manufacturers including those purporting to have ‘durable’ cables failed this bend test!
In summary, we believe that the lack of properly defined cable durability specifications are a significant issue for the consumer electronics USB cable industry and believe that more action is required to help educate consumer to support more informed purchasing decisions in the future. Having bend cycles is a positive step forwards, but this needs to adhere to a common testing standard or have published test details to have any value. As a manufacturer of quality cable products, this is an area that Salom continues to invest in and look forwards to industry wide initiatives (ideally driven by the USB-IF) that will help better guide and support consumers in future. Remember, if the specification is not clear regardless of the brand then do you REALLY know what you’re purchasing?
For inquiries on sustainable power solutions, please don’t hesitate to contact us;
Andy Richardson – CEng MIET , info@salomeurope.com Vice President Business Development, Salom Europe Ltd
About Salom: Salom is a leading global manufacturer of power supplies for consumer electronics products. As a manufacturing partner for global brands, Salom has produced in excess of 3Bn power suppliers since our formation. Salom products are trusted by some of the most successful electronics companies in the world, quietly and efficiently powering devices across the globe for more than 40 years.