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Now this has started to "interfere with concentration". It is happening when i am getting out and trying to close the door. I feel a static shock as i touch the metal part of the door as my foot touches the ground.

I faced it in my last car as well, in that car the seat covers were of velvet cloth. But in this one they are plain (don't know the exact material). Do others face it as well and how do you avoid it?

Or does it has any relation to weather, I think it happens in cold days.

  • I do know that tire composition matters greatly in this conversation. Certain tire brands can generate enough electrical charge to adversely affect radio reception on a new 1989 model. I think they fixed the radios with some capacitor filter modifications. With that said there really isn't much you can do about it. – zipzit May 16 '16 at 13:31
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    new 89 model??? – Moab May 16 '16 at 13:55
  • Holding a penny (or any other coin) and tapping it to the metal first will discharge without any pain. Larger, tighter contact area. – user17370 May 16 '16 at 14:36
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    Be careful, there are legends that the spark can ignite fuel if the discharge happens when you are refueling. – Džuris May 16 '16 at 14:57
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    @Juris - Ignition of non-compressed fuel requires direct flame, a spark is not enough – Taegost May 16 '16 at 19:44
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Yes, the others face it as well. It depends on the pants and shoes you wear, as well as the material of your seats - static charge builds up between the different fabrics when you stand up because of the triboelectric effect. When you first touch a large metal body (such as the car frame), it immediately discharges, giving you the unpleasant sensation. Weather conditions matter as well, this phenomenon is more common in dry air conditions.

One trick you can try is to get out of the car while touching the metal frame of the car. This guarantees the charge will pass to the car before building up. This trick works in other situations when you get shocked by static as well: touching a metal table leg while standing up off a chair will prevent static discharge at home or office.

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    I just use my car keys to touch the door before I open or close it. Works like a charm. – Graph Theory May 16 '16 at 23:13
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    The effect is worse with synthetics, I believe. For instance, when I wore poly-cotton hoodies in the winter, I'd generate enough charge that I'd get a shock from touching metal, such as a locker (or laptop!), but I don't commonly experience the same problem with cotton clothes. – Mathieu K. May 18 '16 at 6:02
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I have experienced it as well, in some vehicles more than others. Typically, the days I get hit with it the most is, as you stated, on cold days. I don't think it's necessarily the cold day which does it, but rather the amount of humidity which is in the air. When the air is dry it tends to allow more static electricity buildup. The humidity is usually lower on colder days due to the fact there isn't as much evaporation going on around you to create the humidity.

On this web page, they talk about this effect a little bit:

These static charges build up normally by rubbing 2 materials together (an effect known as the Triboelectric effect due to the friction of rubbing), for example while walking on carpet while wearing shoes (rubber soles vs carpet material). When the charge builds to a high enough level and you touch an electrically conductive part like a metal door handle, the static charge is suddenly released all at once and you notice the effect. At low enough levels, you do not actually perceive it even though it actually occurs.

When it's humid, it's much easier (as you correctly mentioned) for the static charges that is being generated to dissipate before you touch a door handle. They dissipate away to the environment via the surrounding air & also back to the 'damp due to humidity' carpet.

So when it's humid, less static charges build up to a level required to zap you and when it's dry you get zapped more.

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    Cold days are less humid as cold air physically cannot hold as much water in it as warm air. – Rory Alsop May 16 '16 at 10:32
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    Yes, it's more like DRY days. You get a lot of static shock in very dry and hot climates like Las Vegas, for example. – Chuck Le Butt May 16 '16 at 12:27
  • This is fairly common, in dry climates or seasons, as Chuck Le Butt mentions. I've seen aftermarket car products in Japan for this issue (high-meg conductive pads that are mounts to the car door with a wire to connect to a metal part behind the door panel) and these [link] (amazon.com/Cylinder-Anti-Static-Keychain-Electricity-Discharger/…) must be for the same purpose. – Jake Peters May 16 '16 at 13:56
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    It my be worth noting that on cold days most of us wear much more woven synthetic material (compare waterproof jacket and a fleece hoodie to, say, a plain cotton t-shirt) on these dry winter days, which multiplies the effect. – Pavel May 17 '16 at 13:46
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One can add a strap that rubs on the road. It bleeds off static charge continuously. It is easy to install but has somewhat limited life. They do work, we have installed several over the years.

Vehicle to ground strap

Note also that it is important to bleed off the charge before removing the fuel cap. There are stories of fires being ignited by the spark.

  • I've seen this on old russian cars and nowhere else, which makes me a bit skeptical. Does it actually work? How? – I have no idea what I'm doing May 17 '16 at 6:52
  • @IhavenoideawhatI'mdoing It's made of conducting rubber, that's all. You can try it by hanging a metal chain long enough to touch the road, but the chain is noisy and easier to snap. – Agent_L May 17 '16 at 9:30
  • @Agent_L Ah, conductive rubber. Makes sense, Always thought it was regular plain old rubber. Though is that enough to ground the vehicle? A conductive strip barely touching the asphalt? – I have no idea what I'm doing May 17 '16 at 10:47
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    @IhavenoideawhatI'mdoing Conductive rubber consists of metal wires inside the rubber band. There wires are designed to conduct very low currents because static charges slowly. Look on fuel tank trailers or trolleybuses - these vehicles must be grounded - you shall find several rubber bands touching the ground. Fuel tanks must be grounded to prevent explosions, trolleybusses to prevent discharging through passengers. – Crowley May 17 '16 at 14:03
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    These straps are unnecessary. Tires contain enough conductive materials (carbon, specifically added for this purpose) to provide a path to ground. You're getting shocked because you carry a static charge, not the car. – Hobbes May 17 '16 at 16:48
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You could try spraying the upholstery with an anti-static spray, like what is used on the carpet in computer rooms and offices with computer equipment. Perhaps the spray used on clothing to prevent static cling would work also?

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Or does it has any relation to weather, I think it happens in cold days.

There are two aspects that may make the effect larger on colder days. The main factor is that the air is dryer, so the charge the car develops as it moves through the air can be larger, and takes longer to discharge. The second factor is that people usually wear warmer clothing, and often this type of clothing creates and retains a greater static charge that warmer weather clothing.

Do others face it as well and how do you avoid it?

Yes, as long as the car is insulated from the ground then you will experience this. What's happening is actually two discharges. When you start to get out you are charged to the potential of the car. Then your foot touches the ground and you discharge to the ground. Then you touch the car door and you become the path for all of the car's charge to discharge to ground. It's this second discharge that you feel - the first one happens through footwear and often is unnoticed, also your body doesn't carry as much charge as the vehicle, so the first discharge is relatively small.

A conductive strap hanging below the car works to eliminate this problem entirely. When travelling quickly, the air pushes the strap up so it doesn't wear on the road all the time, but they do have to be replaced periodically. These disallow high charges to develop on the car, and don't themselves create sparks because the potential is simply never allowed to get that high.

I touch the door with the back of my hand or fingers after I get out, so the discharge occurs on the back of my hand or fingers. This is much less sensitive than my fingertips where I'd usually contact the car to close the door.

In theory you can weld small needles to the metal frame of the car pointing toward the ground. When the car is at a high potential, these will emit electrons and discharge the potential more quickly than the rounded, painted edges of the car. I don't know if this discharge would be fast enough to eliminate the shocks you feel, though, since you stop the car and immediately exit, but it should reduce them without the ground contact of a strap. You'll need to choose a metal, alloy, or conductive covering that won't rust, or you'll be replacing them frequently.

If there's a part of the car you hold onto as you exit, attaching a wire from that part to the frame will also work. So on my van I hold onto the door handle as I exit the vehicle. It's plastic, though, so it doesn't conduct the vehicle's charge to me until I touch the outer edge of the door frame. There are screws in the handle, so if I touched the screws, or attached copper tape along the inside edge of the handle to the screws then the discharge would happen at my feet as I left the vehicle, rather than between the door and my hand.

Lastly, you can get some plastic edge guards for the door frame. If you install one and train yourself to only ever touch that as you close the door you should find the discharges go away. If your trip away from the car was short, though, you'll get a shock as you touch the door handle or door when you return.

The conductive strap, however, is a cheap simple solution, available for $10 including shipping from some online stores, and can probably be found or ordered at your local auto parts stores. Hang it well under the vehicle where it won't be easily seen if you don't want well meaning people to constantly notify you that you've got something hanging under your car!

  • Those straps are unnecessary. Tires contain enough conductive materials (carbon, specifically added for this purpose) to provide a path to ground. You're getting shocked because you carry a static charge, not the car. – Hobbes May 17 '16 at 16:49
  • @Hobbes Regulations require a minimum amount of conductivity. However some low quality manufacturers are substituting silica for the carbon black which reduces conductivity, and some good manufacturers have reduced conductivity enough that they design in additional conductive rubber to comply with regulations. If not installed well or correctly, though, even conductive tires may not provide sufficient grounding for the vehicle. articles.latimes.com/1994-07-29/news/… ... moto.michelin.co.uk/advice/faq/… – Adam Davis May 17 '16 at 18:22
  • @Hobbes Also, note that if the "you are insulated from the car but have developed a charge" were true, then you'd get shocked when you touched the key to turn off the vehicle, and this would only happen if you had plastic keys or key covers. I'm still getting shocked from my big ford van with metal key and good quality name brand tires. – Adam Davis May 17 '16 at 18:25
  • You get shocked when you get out of the car because the friction between you and the seat (as you move around to get out) builds a static charge on your body and the seat. The charge on the seat is quickly dissipated, which leaves a potential difference between your body and the car/ground. – Hobbes May 17 '16 at 18:56
  • @Hobbes So you're suggesting that the 2-4 four square feet of moving clothing against the car seat is sufficient to develop the static charge required for a 5-8mm spark, and that there is no other way people are experiencing sparks on modern cars? Given the reviews on amazon that suggest adding this strap resolved the sparking problem for most (but not all) I don't doubt that what you're saying is true for some, but not all. Creating that large a potential difference in the 1-2 seconds it takes to slide off the seat and touch the door seems less likely. – Adam Davis May 17 '16 at 19:00
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Yeah, that happens a lot. I hold my key with my fingers touching the metal, and tap the edge of the door after I turn. I suspect that the turn-while-seated is when the static charge is generated.

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    charge is created when you slide on the seat to get out, movement creates the charge. – Moab May 16 '16 at 13:54
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I had this with a relatively modern car (2008 Honda Civic) a couple of years ago, and it was getting progressively worse. In the end I found that there was a small crack in the battery casing. When I replaced the battery the problem disappeared and never came back, so that might be worth investigating.

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    How would that work, from a physics standpoint? – Mathieu K. May 18 '16 at 3:50
  • Embarassingly, I have no idea. Maybe it wasn’t actually a problem with the battery but a problem with the earth (‘ground’ in US?) connection to the frame? Either way, it wasn’t static shock from clothing. – Robin Whittleton May 18 '16 at 8:02
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After you open the door, but BEFORE you put your foot on the ground, grab a metal part of the car with your hand. Step out of the vehicle, and then release your hand. Your body will still discharge the static electricity to ground, but because you are holding firmly to the car, there is no air gap for a spark to occur, and the larger surface area that you are touching with means that you won't feel the charge.

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