Magnetic Phone Holder for Car.





Introduction: Magnetic Phone Holder for Car.

About: Telecommunication engineer, working in a electronic design company . We make electronics for washing machines, ovens, induction cookers, vacuum cleaners, etc..,

I wanted to put my HTC Hero on my new car but I didn't found a phone holder that fits with this phone due it's a little curved where the buttons are. I've already found a good car holder, but a little expensive (19€). It's a magnetic holder made by an Italian company: and taking the idea of a magnetic holder I decided to make it by myself.
The result is a magnetic car holder that fits with any phone with a battery cover (sorry iphoners) and in any position without making any hole and with a very powerful magnetic strength.

- Old hard drive or flat neodymium magnet.
- Cutter blades.
- Double side tape, thick for place the magnet in the car, thin for place the blades in the phone.

Let's start:

Step 1: Get the Magnets.

I've disassembled  and old 3.5" hard drive and there are two neodymium magnets to drive the reading arm. To detach it from the metal plate you can bend this support with two strong pliers, it will pop out due it's only glued. I've used the two magnets together due the magnet force its higher. It's not necessary to glue them, they are magnets!
Be very careful with this magnets, they are very strong and you could hurt a finger by placing it in a metal part, or you can delete any credit car near them.

Step 2: Place the Cutter Blades.

I recomend the little ones, but you can use any cutter blade or thin material with iron. To help putting the blades you can fix the magnet by some tape behind the cover, the blades will be attached in place in the better position almost alone due the magnetic field. I recommend to put the blades in the same position than the phone will be. If you will use the phone mostly in horizontal  then put the blades like this, but if you will put the phone in vertical then put the blades in vertical. Adjusting its size is easy, due you can break the blade to the size you want.

Step 3: Double Tape on the Blades

I've put a thin double side tape, but you can put a little balls of blue-tack or even a soft glue. This will fix the blades to the battery when you close the battery cover.

Step 4: Testing the Magnet Holder.

Once the phone is closed with the blades inside to see the results you can put the magnets with a thick double tape in any surface and test the behavior. You will notice that the magnets are very strong so be very careful when place the phone. The magnets must be very clean, if the chromed surface of the magnet is gone then put some tape over to avoid scratch the phone.

Step 5: Put Magnet in the Car.

Choose the better position for the magnet in the car and fix it with a strong double side tape. You will have the most easy, effective and comfortable car phone holder ever!!



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    19 Discussions

    self adhesive magnets available on amazon for couple of pounds.

    I've been doing almost the exact same thing for 3-4 years. I made custom fit metal plate that covers most of the back of the phone. Like protoman says, the only thing affected is the compass. I have even tested the compass almost a year. without the metal back on it everything works great. No long term effects. The neo magnets from a hdd are strong enough that I never have to worry about the phone falling off. I can almost throw the phone up there and it will catch it. No fumbling around trying to find your mount. When you aren't using it for the phone, the charge cord will happily hang there.

    One thing I would add. I cut a piece of rubber from an old bike innertube, and I super glued it to the magnet. I then trimmed it with a exacto knife. It gives the phone a little protection from scratching. It also give a little better look than just the shiny magnet.

    If you use the household/plummer/marine goop glue, it will cleanly remove later if you wish. You just have to tape it in place for a day or so so it will set up.

    I also made desktop cradle with round neo magnets and a piece of heat bent lexan. Drill some holes in it and recess the magnets. Cut out a piece of innertube and glue over the magnets.

    2010-03-12 21.03.42.jpg04-01-10 023 (Small).JPG
    3 replies

    Thanks for the results of the long term testing. I only have it mounted from 2 months ago but I don't see any future problem with SD or screen like some people say without thinking about it first. The only problem is that I'm detecting a little magnetization of the blades (not enough to hold a clip). This could be a problem due the compass will be wrong all the time, it happen to you also?

    Yes, the compass is pretty much useless as long as the blades/metal plate is present. Good news is if you remove the metal, nothing is permanently damaged. The compass will calibrate and continue on like nothing happened.

    To answer a couple people here, SD cards are not a magnetic medium. They are solid state circuits. Magnets do not effect LCDs either. Hold a magnet up to your LCD monitor. (carefully) there is a metal shield on the back. It will attract to your magnet and you could break the glass front. (strong magnet)

    The accelerometer is not affected either.

    Nothing to stop you from buying a second hand back phone case and fit your metal to the inside of that one. Keep it in the car and swap if you want to 'stick' your phone to the dashboard.

    It would mean no problems using your compass out of the car too.

    My initial thought was with the blades. Imagine what TSA would do to you if they ever caught those while trying to board and aircraft. Hope you don't have any allergic reactions to latex cause it's gonna be a long day.

    1 reply

    I thing you should check your gsm signal after doing it, because it can cause lower range of signal...

    You said everything works fine with this setup.I have a few hdds I might scrap just to do this for my car and my work truck.This dont affect the navigation on the phone? you said only the compass so wondering if it will still work.I use my phone for navigation if I go somewhere I havent been before.


    1 reply

    The compass will be fixed to one direction due the magnet, but the GPS and all the other radio signals will be work ok, but you must try it with your phone.

    I used a similar setup. I taped a small metal washer inside my silicone case then slipped it on the phone. It is small enough that the compass seems to work just fine, but large enough to hold strongly to the hdd magnet I used. Of course the compass does not work when mounted, but thats why my Jeep has a compass on the overhead info panel.

    don't you think that magnetic pole can in long term destroy some details inside?????

    I have to agree with Mike and tell you that this is a bad idea.

    A magnet near electronics is a bad idea in the first place, but the SD card in your phone is particularly sensitive to magnetic fields.

    You're also using blades for something that isn't cutting (which in my opinion is a bad idea).

    4 replies

    The only problem is with the compass, that don't work well. The mobile signal, bluetooth, position sensors, accelerometers, etc works fine. I put the phone every day almost 2 hours in the magnet and works perfect from a month ago. The electronics have problems with the electric fields, not the magnetic fields. The magnetic fields can generate a voltage if this field changes in time, but in this case the magnet it's fixed. And "the SD card in your phone is particularly sensitive to magnetic fields." in 19 years studying  and working with electronics never listened something like this, could you explain in what is based this argument?
    I use blades because they have a good level of iron and work well with magnets, you could say another cheap and thin material instead this.

    the magnet can also corrupt memory in the phones database and if left there long enough damage the crystal or lcd display on the phone. This is not a good idea at all. also the razor blades are just a horrible idea especially in a car lol

    The magnet doesn't affect the memory or lcd, please could you explain why you say this? The razor blades are inside the battery cover, you don't see or touch them, please read carefully before say something is a horrible idea.

    SD cards are flash based and therefore not sensitive to magnets like floppy disks or harddrives that are magnetic. I dont see anything that would be a problem with the magnet.