Speed is relative. The impact threshold for the process is based on a transient impact of 5 to 7g, at a crash speed of between 5 to 15 mph. The variance is based on several factors, including angle of impact, its characteristics (meaning a direct, or deflected secondary hit), transient velocity, or other pressure metrics, as established by the on-board airbag system instrumentation.
On sensing a collision an airbag will deploy in an average of just 30 milliseconds.
The force of the collision has to great enough
An airbag depoys when a hard impact its the vehicle and the airbag automatically deploy's before the driver and passengers hit the front of the car/seat.
it will deploy if hit hard enough.
It is suppose to deploy in a frontal crash
No an airbag will not deploy if the battery is disconnected
The airbag system has a malfunction and will not deploy if needed as long as the airbag symbol stays on.
Once
If the car is off and no one hits you the airbag should not deploy. If you are driving and stopped at a traffic light and someone hits you, the airbag could possibly deploy depending on the impact of the accident.
200 mph
It's most likely a broken clock spring. Does your horn work? If it doesn't, it's most definitely the clock spring. It's behind the airbag. From what I've been told, the airbag won't deploy, even in an accident.
Drive and hit a brick wall, the airbag will deploy. Then remove it.