We've all got that drawer or box somewhere in our homes that is filled with old chargers and USB cables. The one that we keep just in case they'll be helpful, which isn't a terrible idea when new devices don't come with charging bricks. I've possibly got more than most, because of a decade of tech journalism plus another decade of early adopter-itis before that, and I got wondering if I should ditch the drawer.

It turns out, I should have recycled most of the chargers I've collected. Some were old standards that don't work on any of my recent devices, others put out incorrect wattage or voltages than what the label says, and some were just plain old and decrepit.

Your USB chargers have one job

And they're not always doing it correctly

I've got dozens and dozens of USB chargers scattered in drawers around the house, and probably more that I've forgotten about in boxes in the garage. And only a few of them were performing as expected, with the ones closest to specifications being power bricks for laptops that use USB-C.

Some of the chargers were multi-port ones, and were supposed to provide 100W on either port if only one cable was plugged in, but were only negotiating at the lower PD level advertised for when both outlets were used. Others had incredibly low charging speeds, even on fast charge enabled devices, so those need to go.

Others had no issues unless the cable was moved, and a few showed higher wattage than rated but not by more than 5%. Some of the chargers had the same behavior on multiple cables, and even on known good cables that tested fine otherwise. I wouldn't have known without using a USB tester on them, one that can simulate a load so it will pull the various USB Power Delivery amounts that the charger was designed to provide.

Your USB cables are no better

Not every cable is built correctly

USB cables of any kind are supposed to have low resistance on VBUS and ground pins, which means less wasted power thanks to the heating effect. They're also supposed to not change in characteristics when you move the cable or flex it, and negotiate the correct USB-C Power Delivery setting for the expected pairing of device and charger.

And then there are the myriad of different USB-C cables, whether they're USB-C to USB-C or USB-C to USB-A. Some are charge-only, while most pass both signals across their length. USB-C to USB-A can have two different resistor values inside, and that can be a problem for some chargers.

That's for lower power cables. For high power cables of 100W or above, you also want an e-marker chip and also for it to advertise 5A capability. This can be tested with a USB tester like the one I've been using, and if the cable says anything other than yes, don't use it.

I'd been wondering why one of my chargers was unable to charge at its 100W rating, and it turns out that the cable I had bought didn't have a correct e-marker chip, wasn't able to handle 100W, and was showing 5.2V when no load was applied. The voltage difference from the 5V standard wasn't a problem, although it wasn't changing from 5.2V when PD was triggered, so something wasn't negotiated correctly. The other two things were also issues, and I could have damaged devices, my charger, or even the socket that the charger was plugged into.

Standards are there for a reason

But not everyone plays nicely

The USB charging standards are well established at this point, and have been for many years. That hasn't stopped some companies playing fast and loose with those standards, and whenever that happens the results can be disastrous. It doesn't have to result in fires, although that's one possibility, but often the wrong charger with the "correct" device causes irreparable damage.

Perhaps the best example of this in recent memory was the Nintendo Switch, which started "bricking" in 2018 with some third-party docks. Now, Nintendo didn't follow the USB-C standard to the letter to make the Switch slide really easily in and out of the dock, using a slightly narrower USB-C plug. Third-party dock manufacturers had to guess at the spacing, and if you put your console in just so, you accidentally touched a 15V pin to the Configuration Channel that's rated to a maximum of 6V.

But there were two other issues: if you used a 10K ohm USB-C to USB-A adapter cable with a low-power charger, you could damage the charger. And one with third-party dock manufacturers not using a dedicated PD controller to save costs — some docks used a general microcontroller that would send 9V instead of 6V over the Configuration Channel, also damaging the console.

So, lots of standards issues on all sides, partly showing how complex USB-C actually is. But also, that "cheap" chargers or docking stations are not worth the potential for damage.

I'm replacing my chargers (and most of my cables)

Between the years of shifting USB-C standards, adapters, and power bricks, my charging drawer has a lot of chargers that don't work properly. Some of them have worn down over time, others were designed for standards that aren't in use much anymore, but all the ones with odd voltage issues are dangerous either to themselves or the devices charged by them. If you've got a brand-name charger from the last few years that does USB Power Delivery, you're probably fine, but it's wise to check all your older chargers and cables, replacing them if necessary.