Like Tree4Likes
  • 1 Post By jonnycutter
  • 2 Post By BrooklynBravest
  • 1 Post By Ausfirery

Thread: Will cutting the battery power trigger the airbags?

  1. #1
    Forum Member

    Join Date
    May 2012
    Posts
    6

    Default Will cutting the battery power trigger the airbags?

    Hi all, its a commonly repeated statement in my department that "In the old days we used to cut the power to disarm the airbags, but nowdays we don't, in modern cars that can trigger the airbags"

    I never really had reason to question that teaching, but as I started browsing here, I noticed that you all talk about cutting the power to disarm the airbags.

    Whats the go?

    (Im in Australia, if that makes any difference)

  2. #2
    MembersZone Subscriber

    Join Date
    May 2000
    Location
    Wheaton IL
    Posts
    1,767

    Default

    In my experience I have NOT seen an airbag get triggered by cutting the power. Airbags can still go off after the power has been cut and before the capacitor has drained. In older cars it could take 20 minutes for that capacitor to drain. In todays cars a few seconds to several minutes and the system should be disarmed.
    Remember with airbags their are different ways of triggering the bag, some use stored pressure and some use an explosive charge, so be careful not to cut components while doing an extrication. The best advice is to cut the power as soon as possible and peel and peek before doing any cuts.
    Some of the manufacturers have excellent videos on their websites or you tube pages. Do some looking around and I'm sure you'll find some good stuff
    http://www.genesisrescue.com/html/training.php
    http://www.amkus.com/resources/training/
    http://www.holmatro-usa.com/training

  3. #3
    Forum Member

    Join Date
    Nov 2009
    Posts
    3,944

    Default

    Quote Originally Posted by Griskard View Post
    Hi all, its a commonly repeated statement in my department that "In the old days we used to cut the power to disarm the airbags, but nowdays we don't, in modern cars that can trigger the airbags"

    I never really had reason to question that teaching, but as I started browsing here, I noticed that you all talk about cutting the power to disarm the airbags.

    Whats the go?

    (Im in Australia, if that makes any difference)

    Welcome

    Yes you have to cut down under on the wire when you cut the wire

  4. #4
    Forum Member
    EastKyFF's Avatar
    Join Date
    Feb 2001
    Location
    Nippa, KY
    Posts
    3,122

    Default

    Quote Originally Posted by fire49 View Post
    Welcome

    Yes you have to cut down under on the wire when you cut the wire
    And the seasons are backwards, so your weather will be different when you are working the extrication. ;-)
    I am more than just a serious basketball fan. I am a life-long addict. I was addicted from birth, in fact, because I was born in Kentucky.
    ― Hunter S. Thompson

  5. #5
    Forum Member

    Join Date
    May 2012
    Posts
    6

    Default

    Quote Originally Posted by EastKyFF View Post
    And the seasons are backwards, so your weather will be different when you are working the extrication. ;-)
    Will the increased humidity in winter result in more likelyhood of static electricity discharge, and if so, do you think it would be a good idea to advise people to have their car crashes in summer?

    So basically its just nonsense being spouted by someone who didn't know what they were talking about, followed by a significant number of people repeating it because the first guy seemed to know what he was talking about? So sick of that being a problem haha.

    Although, I like how you guys have the problem with the 16ft rule for keyless ignition cars. Over here the oft repeated number is 30m, which is something like 100ft. I guess give the fob the the probie and tell him to go for a run? Haha

  6. #6
    Forum Member

    Join Date
    Jan 2007
    Posts
    77

    Default

    Hi Griskard

    Cutting the power reduces greatly the risk of an accidental airbag deployment. Ignition off, disconnect the battery if accessible. Disconnect neg terminal first to avoid sparks etc. Best to use spanner incase reconnection is needed.
    Cutting wiring looms that hold SRS wires does pose a small risk and is best cut with insulated cutters, there is the risk if a short setting off SRS however this is rare. If all else fails maintain good safety distances from undeployed bags and use safe procedures.

    Hope that helps

    Jon
    Matt_Lato likes this.

  7. #7
    Forum Member

    Join Date
    Jun 2013
    Posts
    122

    Default

    For the sake of not repeating all the above, I will just add one bit of accessory information.

    Don't physically CUT the power cables unless you cannot by any other means simply disconnect it.

    There has been instances with victims pinned in the driver seat, where all the rescuers had to do is utilize the power seat to buy another 1 or 2 inches and free the victim. As soon as you physically severe that cable in two, that goes out the window.

    Get in the habit of taking 15 seconds to pull out your pliers and disconnect it rather than jumping right to cutting it, even for BS calls.
    RangerJake72 and Matt_Lato like this.

  8. #8
    Forum Member

    Join Date
    Mar 2003
    Location
    Wilmington, Vt.
    Posts
    62

    Default

    We are taught both ways. But, as BrooklynBravest stated, we push "disconnecting" if at all possible. There didn't used to be so many electrically operated items on older cars. Now, it's very common to find multidirectional electric seats, electric positioning pedals, electric positioning steering wheels, and of course, electric door locks. Take the time to see if cutting the cables will either help or hinder you.

  9. #9
    Forum Member

    Join Date
    Nov 2013
    Posts
    6

    Default

    Quote Originally Posted by Griskard View Post
    So basically its just nonsense being spouted by someone who didn't know what they were talking about, followed by a significant number of people repeating it because the first guy seemed to know what he was talking about? So sick of that being a problem haha.

    Ah yes, one of the biggest problems in our line of work is those persistent myths, misunderstandings and untruths that people spread and repeat without having a solid understanding of the subject.

    In regards to your question, it is important to understand the reasoning for isolating power to the vehicle.
    We do so to prevent the sparking of electrical components that may cause a fire and also to reduce the risk of an accidental airbag deployment.
    We can start the proccess of de-energising the SRS system during our initial contact with the vehicle by switching off the ignition. No iginition = no power to SRS computer. However a common cause of accidental airbag activation during a rescue is when a live wire is shorted to the SRS system.
    An example of this is the widely seen video of a firefighter in Ohio who was struck by an accidental airbag deployment. In that case the battery was not disconnected and which displacing the dash from the centre console the tip of the spreaders penetrated the SRS computer and the other tip contacted a positive wire resulting in a short to the SRS computer triggering the deployment.
    So it makes sense that the ideal senario is to initially switch the ignition off and then disconnect the battery which removes power from all circuits and prevents a connection or wire from another circuit connecting with the SRS system (the computer or wires connecting to the airbags).

    The reason someone may say that the battery on modern cars should not be disconnected is most likely due to the increased use of power seats and accessories in newer cars rather than the possibility of accidently activating an airbag (or else you would run the risk of this every time you replaced the battery in your own car!)
    We can work around this by a) identifying power seats first and moving them into a better position before disconnecting the battery or b) as alluded to by others above, avoid cutting the wires and disconnect the battery connections with pliers or a shifter so they can be reconnected if required later.

    Obviously there are going to be times where disconnecting the battery is not practical or possible ie. vehicle on roof or battery located under occupied passenger seat.
    No big deal, we take care in tool placement, expose the trim before cutting and maintain safety distances (all of which we already should be doing).

    I hope this helps. In the meantime stay safe and think critically.
    From a fellow aussie, cheers.
    Matt_Lato likes this.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Cutting the battery. Not as important?
    By GPM1230 in forum University of Extrication
    Replies: 30
    Last Post: 11-15-2009, 01:17 PM
  2. Cutting the Battery in an Overturned Vehicle
    By 224FFEMT in forum University of Extrication
    Replies: 5
    Last Post: 01-29-2006, 04:54 PM
  3. Removing battery power?
    By arhaney in forum University of Extrication
    Replies: 16
    Last Post: 11-14-2004, 07:22 PM
  4. Will Cutting Cables Deploy Airbags?
    By rmoore in forum University of Extrication
    Replies: 4
    Last Post: 02-05-2004, 10:15 PM
  5. Cutting out deployed airbags
    By jsdobson in forum University of Extrication
    Replies: 5
    Last Post: 09-07-2001, 10:41 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Log in

Click here to log in or register