Always on USB charge port


This simple and clever guide to installing an always on USB port comes from the Team Hack-a-Day forums (originally created for the team’s Folding@home efforts). [Cerberus] added a USB port to his computer case that always has power, even when the computer is off. The power comes from the +5VDC standby line in the motherboard connector. You can use this new port to charge any USB based device.

Comments

  1. Jax184 says:

    On some modern motherboards the USB ports remain powered even when the computer is turned off. My Asus P5W DH Deluxe does this.

    This means I need to not only shut down my computer but also switch it off at the PSU if I want to reset my buggy internal USB card reader…

  2. ejonesss says:

    if the computer is like the earlier macs with usb where there is an on keyboard power key then there should be power to the keyboard to make the power key work

  3. James says:

    Aren’t most powered USB hubs able to supply power even when not connected to a PC? I think mine does…

  4. dandin1 says:

    Most modern motherboards do, but I beleive the device cannot request full power, so no charging.

  5. yeah, I always just used a hub for this. no need to mod my compy and since it’s a laptop anyway, no worries about discharging the main battery.

  6. pokey says:

    Most motherboards allow +5VSB to SOME of the USB ports when soft powered off. However, out of cheapness a lot of manufacturers forego the USB standard current switch and use a single poly resettable fuse for 5V on a port pair. That’s why you can charge a cell phone and run a fan from USB without having something attached to the data lines to do negotiation.

  7. ApprenticeWizard says:

    Note that, by the ATX standard, the +5VDC standby line is rated to 10mA max. This is far less than most thumb drives require, much less an iPod.

    It would be better to use an external, powered USB hub.

  8. miked says:

    i approve of this post

  9. yeah, that’s what I mean.

  10. Whackpak says:

    and your usb drive can not be destroyed when you pull him out while there is power on it?
    I’d like to know this because I want to do this hack on my old pc :)

  11. Miles says:

    Great, finally a feature that has been on my last 5 motherboards via jumper is now available as a dangerous hack.

    Sorry, it ls hack worthy if you haven’t a proper bios / jumper to enable this.

    Frankly though, if I had a PSU cheap enough to consider doing this to, I would worry about its ability to provide enough standby power to charge anything.

    A real hack would involve some kind of standby-power **Removal** for both your monitor and PC, perhaps an IR Atmega8 controlling a relay that cuts the power to all your PC equipment and wall-warts, and then will switch power back on and hit their soft power buttons. It could probably run off of a solar panel and a small battery, thus saving all of that power. Put your TV/VCR/Tivo/DVD/Stereo on one as well, get rid of all this damn “standby” crap. One efficient source of supply instead of every device having a separate parasitic drain just for the “convenience” of a soft power button.

    Freaking wasteful appliances.

  12. Joe says:

    Miles,

    I use a standard household light switch (rated at 15 amps) and a handful of outlets wired together to do the same thing.

    That way, when I go to bed, my room is not bathed in the lights of many ‘standby’ leds.

  13. Miles says:

    Cool, sorry if I seemed overly negative, it is just that this doesn’t seem like much of a hack.

    Maybe I am biased and need an Atmega or a Fpga to feel that hacky goodness. Even a Dreamcast VMU potatoe would probably heal my jonesing.

  14. Dark_AvEnGer says:

    the new ATX standard actual is around 2amp on the 5vsb not 10ma.

    most motherboards have at least a couple of ports that stay live when the computer is off but not all.

  15. Amos says:

    @ Whackpak:

    A well designed drive should not care about sudden power loss.

    When you “Safely Remove” a drive in Windows, all it does is flush any files you’ve written from the cache to the drive and check if there are any files on it that programs still have open. It doesn’t power down the drive. I know because I have an el-cheapo drive that just blinks its LED about 1 Hz and it still blinks after “Safely Removing” it.

    @ Hackaday:

    What’s up with the alternating widths of comments? It’s kinda annoying…

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