Not long ago, if you left for a trip without your cellphone’s proprietary charger, you’d likely have to go to an actual store and find a compatible device from over a dozen different models.
At that time, even among the same phone carrier, charge cables were rarely interchangeable. The cynical among us would assume that this was a phone manufacturer’s ploy to sell more aftermarket parts. Fellow cynics could also believe this was a matter of poor long-term planning and coordination on the product designer’s part. Either way, if you forgot your charger in the 90s or early 00s, you had to shell out for a new one. Today, you can simply plug into a friend’s charger, gain a needed boost and be on your way.
A New Standard Emerges
We rarely appreciate advances in technology when they filter into our products little by little. If you have an Android, Blackberry, or Windows phone, you only need one connector: a Universal Serial Bus (USB) Micro-B. Many newer phones are adopting USB-C, and we can expect this new standard to become near-ubiquitous. Other devices, like Lenovo and Apple computers, utilize USB-C for power, data transfer, and even video signal transmission, making this a very versatile plug.
Notable exceptions to the apparent USB-C takeover are Apple iPhones and iPads, which use the proprietary Lightning connector, introduced in 2012 to replace Apple’s older and much bigger 30-pin connector. While there has been some push for them to adopt USB-C—especially by the European Union—Apple has held fast to this type of connector. While profit likely plays a role, Apple has some justification for this standard; the Lightning connector is thinner than USB-C and Apple released it as a reversible connector nearly two years before the USB-C appeared. Given Apple’s obsession with keeping their products thin, their refusal to accommodate the extra width of USB-C is unsurprising. On the other hand, it’s plausible that they have plans to eliminate this port to implement entirely wireless charging and data transfer.
USB-C Challenges
Apple iPhone/iPad/iPod thickness aside, USB-C has one small drawback, at least in the short term. The full-sized USB type B connector, Mini-B, and Micro-B that came before all used a standard USB-A connector to plug into a computer or charging base. This means if you have a USB power source with a female socket, your cable is nearly guaranteed to fit. It may not provide the proper amount of current or the right communications pins, but at least it would nominally “plug in” and provide some power.
As these USB-C cables become more prolific, we will see a large number of USB hubs become obsolete. We’ll begin to see dual A/C hubs filter into homes and offices to accommodate this fragmentation. Once this standard becomes the norm, you’ll never have to worry about which end of the cable you’ve grabbed, and you won’t attempt to plug it in upside down for the third time in a row.
Besides the physical design, another charging system concern is the actual amount of power that a “power brick” or “wall wart” can supply. Here’s a quick overview:
- USB peripherals: These use 5 V DC for communication, and nominally supply 5 V power. With the various USB Battery Charging and USB Power Delivery standards released between 2007 and 2017, USB charging voltages can vary from 5 to 20 V, and up to 5 A of current can be made available.
- Low-power devices: These include keyboards or similar devices. They draw less than 100 mA at 5 V. This gives a very wide range of power requirements, from .5 W to 100 W.
Given this disparity, it’s easy to see why a manufacturer wouldn’t implement the most capable power supply in all cases.
A Future Charging Utopia?
Is a universal power supply in our future—one that can supply the proper current and voltage on-demand? While a charger may never be truly universal, we’re getting close. You can already find a charger that will slowly charge almost any phone for a couple of dollars at a convenience store. Both do the job, but don’t expect the two-dollar model to work as well as the charger that’s carefully calibrated for your device’s needs.
As far as the actual connectors go, it seems that (non-Apple-related) things are settling on USB-C. This is a positive sign, but it takes old standards a very long time to die out completely. We’ll see where things stand in 5, 10, or 20 years, but I’d bet some people will still be using USB-A connectors—probably even serial cables in some cases. We may see a brand new connector or the takeover of true wireless charging. Whatever happens, tech will continue its march forward. Let’s hope that means fewer cables stored in our accessories drawer.
Zach Wendt and Jeremy S. Cook are engineers who cover emerging technology. Zach, with Arrow Electronics, has a background in consumer product development. Jeremy writes for a variety of technical publications and has worked in manufacturing automation. Go to Arrow Electronics to learn more about power supplies here.
