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.
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.
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.
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.
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.
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?
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!
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.
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.
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.
