USB-ify Your Old Cell Phone Chargers


If you’re like us, you probably have a box (or more) of wall warts lurking in a closet or on a shelf somewhere. Depending on how long you’ve been collecting cell phones, that box is likely overflowing with 5V chargers: all with different connectors. Bring them back to life by doing what [Martin Melchior] did: chop off the ends and solder on a bunch of USB jacks.

You’ll want to use chargers rated for at least 500mA (if not 1A) for this project, or you may be wasting your time considering how much current devices pull these days. Get your polarity right, solder on a USB jack, and you’re finished. Sure, it’s a no-brainer kind of project, but it can clean out some of your closet and give you a charging station for every room of your home and the office. [Martin] glued the USB jack directly onto the adapters, so there are no tangled cords to worry about. iPhone users will need to do the usual kungfu if you want your Apple device to charge.

27 thoughts on “USB-ify Your Old Cell Phone Chargers

      1. Prongs have a similar size. European plugs are better than US and Chinese ones: they don’t unplug too easily if you trip over the wire.

        UK plugs are the best if you ask me and would love to have them at home:
        – they’re fused
        – the live and neutral holes on the socket only open if the ground pin is inserted (very good protection if you have kids)
        – the wire comes out perpendicular to the force you need to apply to unplug the plug making it had to unplug inadvertently.

    1. Uh I don’t think so lol. It’s so simple that people do it regularly without thinking anything of it. The same way that many people cut the end off a 12v wall wart for LED strips and so on.

      The article doesn’t even bother talking about one of the major things you need to consider when doing this, which is to short the data pins to make your phone/tablet charge at a higher rate than the normal 500mA.

    2. This is one of those hacks that is so simple that noone has thought of… taking pictures of it and sticking it on a blog.

      Pretty much everyone has done it, it’s about as obvious as chopping off the good end from a broken wallwart and soldering it onto another one with the same voltage.

  1. I’ve done that already with a couple of my chargers :)

    But I tend to leave whole cable and attach USB connector at the end where the old one was. This way I have long cord :)

      1. Ever noticed that USB plugs have the logo on only one side? That side is the top, so now you can plug it in in one go rather than the usual three.

        When vertical (eg side of TVs) the logo goes toward the front (or left when on the back, eg PCs).

        For molded plugs you can feel which side has the logo and flip it the right way ’round first. (Apple et al just print the logo on there which isn’t quite as helpful.)

        Putting the socket upside is annoying (and shows the maker is one of many who doesn’t know USB does in fact has orientation.)

  2. Did it years ago…except I used an old USB1.0 portable hub. Unsoldered the USB cable and soldered on a fairly hefty 5v wart. I can charge four devices and only use one ac outlet.

    1. “Use a crappy wall wart, get a crappy result” still applies. I would be testing any wallwart before repurposing it like this. I’d want to see the noise/ripple on an oscope, I’d want to load test it to 1.2A (so I had a clean 0.01A-1.00A range to view), I’d want that to be a standing load test (5 hours seems reasonable) rather than an instantaneous load test (the cheap chargers get squirrely with loads over time, sometimes dropping charge current radically after the first several minutes).

      In short, before I trust any device on a charger, I want to know that the charger isn’t going to futz something up. Chargers are cheap, testing is cheap, many gizmos (and certainly the data entrusted to them) ain’t cheap. I would just go trusting any charger printed with “5V”. At this point, I’d assume we’ve all heard the horror stories or gotten duds ourselves from eB or DX (or we know folks who have). Why take a blind risk?

      1. If they are repurposing existing chargers wouldn’t it be safe to say that they had already proven themselves by being used successfully in their original applications?
        Nowadays I totally agree that new ones should be vetted, but it could be argued that time has already done your QC for you on these.

  3. I suppose this could be called a hack but its not really “look what i did” worthy. I keep old chargers and often search thrift stores and pawn shops for chargers. I have plenty of motion sensing lights that run off chargers with chopped off ends soldered or taped on the battery terminals. Cheaper to replace three sets of batteries on lights placed strategically than to be replacing all of them.

  4. Why bother? While this is an obvious solution, it’s searching for a non-existent problem.

    I’ve got about 5 extra USB chargers, plus some with older mini USB connectors. This weekend I was at a yard sale and saw a USB charger with a micro USB cable for a dollar. I can always use an extra micro USB cable, but had no need for yet another USB charger, so I offered the seller 50 cents for just the micro USB cable.

  5. I think ANYTHING you repurpose instead of throw away is NOTEWORTHY… let alone the INITIATIVE TAKEN to just tinker around or be creative!
    Alot of NEGATIVITY going on here with REPLIES..
    Come on BOYS…We know some of you do BIGGER PROJECTS …and/or YOU’VE done something BETTER.. THE POINTS to change something or just experiment or recreate…

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