Update: Custom Cellphone Induction Charging

This is a custom back plate with induction charging circuitry that [Derek Hughes] build for his HTC HD2 cellphone. When we checked in with him last week he showed us how to add an inductive charger without voiding the warranty but it wasn’t very pretty because the stock back plate blocked the inductive field and couldn’t be used. The solution he came up with will work with any device if you want to put some time into the build.

He took two different aftermarket cases; one fits his cellphone and the other is a BlackBerry case meant for housing a credit card. After cutting a hole in the back of the cellphone case he epoxied the credit card holder in place, smoothed the seam with Bondo, and repainted. Not only does the charger fit in the credit card case, but there’s still room for a credit card. [Derek] also measured the magnetic fields around the circuitry and found they will not damage the magnetic strip on that American Express Black you’ve been keeping on you. In the video after the break he mentions the last step in finishing this case will be to locate a 90-degree USB plug as the current connector is a bit of an eyesore.


12 thoughts on “Update: Custom Cellphone Induction Charging

  1. Well Derek has an ongoing process to perfect his hack. In event he does or doesn’t find a 90 degree connector he will have to again to make another case, or mod this one. With finding a connector it will still be an obtrusion. Without find a connector he will have to hack is own solution for the connection, that most likely be an obtrusion as well. Both will require a case mod to protect the connection, while a slight bump most likely will remain, but shouldn’t pose any hassle. No doubt Derek will get this to close as perfect as possible. In the video Derek didn’t say he actually measured the fields around the device, but said his research revealed they shouldn’t be high enough to pose a threat to card magnetic stripes. One of those things that everyone has to decide their own comfort level

  2. The general purpose charge kits from the carphone warehouse have usb adapter stubs with plastic covers that snap off, exposing a nicely accessible plug to match your phone.

    Might be an option for making a nice minimal connector for this kind of project.

  3. why not try a little piece of pcb and a flex cable ?

    that way you can glue the pcb with flex cable into the case and you just have to insert the phone butt first.



  4. Am I the only person who doesn’t see what the big deal with plugging in your phone? ??? says microusb is the first thing to go out but oddly enough I’ve never seen or heard of one. The idea of not plugging it in is cool but you’re still going to plug it in in the car

  5. I just saw these backplates on clearance at Radio Shack for $5.97 so I bought two and I’m half way to a touchstone charging Vibrant. The touchstone unfortunately was full price. Just have to figure out a better way to handle the usb plug. Everything fits fine underneath the Vibrant’s backplate (w/o modification) and it does charge when I jumper it up.

  6. In this case design, you could improve your FM reception by attaching a few inches of wire to a right-angle 3.5mm headset connector (just embed the wire up the side of the case material).

  7. Sure I want the weather at the home srceen with information updates, sure I would like contacts visable at any given time, I desire a educate app, a flight app, a road congestion status app and yes I need a phone in an effort to reply to my every command and not grasp/freeze or shutdown like my present Nokia E72 or my previous Blackberry Bold.

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