[JoeCool88]

As we all know the sheet metal passenger cell of a conventional car forms a Faraday Cage. I'm happy that it never happend to me, however scientists say that it protects you against the aftereffects of a lightning strike. Does anybody know if the i3 passenger cell, which is made of glas fiber and carbon fiber composite material, is a Faraday Cage, too?
If yes a short explanation why would calm me when driving through a Thunderstorm

[Noggie]

well I guess its not a true faraday cage in any cars, if it was you phone would not work inside the car for example.

When I was an aircraft tech 20 years ago, the carbon fiber fairings on the planes were coated with a special conducting primer to divert lightning bolts to the special lightning diverters on the wings.

My guess is the BMW has either fitted some sort of conducting bonding between the parts of the body in the mold, or they have used a similar conducting primer.

I would not be worried about driving the car in a lightning storm.

[ovekvam]

Originally Posted by Noggie

well I guess its not a true faraday cage in any cars, if it was you phone would not work inside the car for example.

When I was an aircraft tech 20 years ago, the carbon fiber fairings on the planes were coated with a special conducting primer to divert lightning bolts to the special lightning diverters on the wings.

My guess is the BMW has either fitted some sort of conducting bonding between the parts of the body in the mold, or they have used a similar conducting primer.

I would not be worried about driving the car in a lightning storm.

Conductive primer is also used to be able to paint the panels with electrostatic paint equipment.

[JoeCool88]

So hopefully the lightning respects the anti static primer, when it arrives with the speed of light, approx. 40.000 Amps and up to 1 GV
I'll raise the question to BMW, keep you informed.

[ovekvam]

The current will want to follow the path of least resistance, which could very well be the conductive primer. But the capacity of the primer could be too low, causing some of the current to find alternative paths.

[vreihen16]

If a lightning bolt can jump 10km through air, I would not count on 1mm of conductive paint to stand in its way! Sorry grandma, but 1cm of rubber on my shoe soles also isn't going to save me from a direct strike, although it does help to prevent indirect-strike injury due to ground conduction from a nearby strike.....

[ovekvam]

Originally Posted by vreihen16

If a lightning bolt can jump 10km through air, I would not count on 1mm of conductive paint to stand in its way! Sorry grandma, but 1cm of rubber on my shoe soles also isn't going to save me from a direct strike, although it does help to prevent indirect-strike injury due to ground conduction from a nearby strike.....

The purpose of a faraday cage is not to stand in the way of the current, but to give it an easier way. And the paint is a lot less than 1 mm thick.

[Noggie]

As the lightning will take the path of least resistance to the ground, the primer will work.
Your tires are conductive, so the current will end up in the ground.

You will be fine as the current will follow the outer edge of the body/frame and through the tires to the ground.

If the conductive paint has worked guiding lightning on Boeing passenger airplanes for more than 60 years, it should work well on a car.

[JoeCool88]

Originally Posted by Noggie

As the lightning will take the path of least resistance to the ground, the primer will work.
Your tires are conductive, so the current will end up in the ground.

You will be fine as the current will follow the outer edge of the body/frame and through the tires to the ground.

If the conductive paint has worked guiding lightning on Boeing passenger airplanes for more than 60 years, it should work well on a car.

I think it was the aluminium airframe Faraday Cage which protected the persons on board. Reason for the conductive paint is to permanently discharge the static charge coming from the "rubbing" of the air molecules on the airframe in flight. I contact BMW, then we will know how they solved the problem on the i3.