Cutting vs. Disconnecting Batteries

[Resq14]

I researched this topic on google and in the search feature here, and could not find compelling reasons to do one vs. the other. I see indications and lots of pointers on when to "cut/disconnect" but not a lot of which one you should do and why. Some say you should d/c so that power can be restored to the vehicle to move seats, windows, etc. Others say cut it to avoid accidentally energizing the vehicle.

I strongly advocate cutting. If you need to move windows and seats, this can be done before power is secured. By cutting each cable in two places and removing a "chunk" of cable, you prevent accidental contact from happening. Why is this important to me? SRS/SIPS/etc devices, fuel pumps, spontaneous ignition of the engine (had that happen last month)... all important things in my opinion. Yes, you can d/c and then wrap in electrical tape. I think it's going a little overboard though personally, when the vehicle in question has just collided. I've seen battery "side terminal wrenches" in trade mags, but have never used one. It always seems like we end up messing around with an adjustable wrench and rusty/corroded screws, creating more sparks than a simple cut creates. And many times the hood would have to be forced to permit use of a wrench, when a pair of cutters could be slipped in the same opening and utilized.

Anyhow, what "sparked" this post was a situation that developed this past month where a customer was not happy that the cables had been cut. It was not a working extrication -- all subjects were out of the vehicles. Both vehicles (minivans) had sustained moderate frontal damage (I thought they were both totaled, which was one reason I didn't hesitate to cut. The other was for the reasons already mentionned). Fluids were all over the road, public safety personnel were in and out of the vehicles, front airbags had deployed. To me, it was within reason to cut the battery cables.

How does everyone else do it? Do you cut it in some instances but not others? Or always disconnect it?

(Whichever way we do it, we \start with the negative terminal, then secure the positive terminal... I think most everyone agrees on this)

[RyanEMVFD]

if we can disconnect the batteries we will and then cover the ends with duct tape. but we will cut them if we have to. it's more or less do as little damage as possible especially on the minor damage vehicles.

[ff7134]

Basically the same at Ryan. Just depends on extent of damage.

[lutan1]

Here we go again...

I'm a firm beleiver in disconnecting, especially with new car technology. There are so many situations with powered devices on cars inhibiting our extrication efforts such as electric sliding seats.

I've been involved in extrications where power has been disconnected and we've had to slide electric seats back- how do you do it when you've cut the cables?

If you need to move windows and seats, this can be done before power is secured.

That's fine if you can predict every thing that may be entrapping the casualty from the outset. If not, you need to be able to cater for the unexpected....

[Resq14]

Originally posted by lutan1
Here we go again...

I'm a firm beleiver in disconnecting, especially with new car technology. There are so many situations with powered devices on cars inhibiting our extrication efforts such as electric sliding seats.

I hadn't seen the specific "cut vs. d/c" debated here yet... maybe I missed it.

And I'm coming at this as more of a safety issue for me and my crew (and in the end, the patient). If it's safer for us, I'd rather work with some inhibitions.

One thing to keep in mind... everytime you "re-engergize" the vehicle, you have to wait for the system to drain again. I wouldn't be wild about putting power back into the car once I've secured it and had people inside.

[Bones42]

We try to disconnect before cutting, but again, the situation dictates it. If we can't access them easily, they are cut. If they are too corroded to not disconnect, we cut. Once in my 20+ years did we have a wish to reconnect the batteries, and it was to make things easier for the tow truck operator later. Not saying it can't happen, but we haven't had the need.

[Fire304]

I think its important to point out that the battery "cable" resq14 cut was called a "wiring harness" by the insurance company and estimated replacement cost was over $1000. Now, I too thought the vans would be totaled, but appearently the insurance company decided to screw these ladies and make them fix it, hence the complaint we recieved. I guess its a good thing I didn't punch out the window to get the keys out.

[Adze39]

If the car is totalled or the engine is going to need to be replaced, might as well save time and cut them. If the car only has minor damage, disconnect them.

[MalahatTwo7]

We try to disconnect where possible, and in particular if the veh is more or less in good shape. Need of accessory equipment inside will also dictate which we do.

As a matter of note, we had a Dodge truck fire last night (28 Apr). The box and cab were totally destroyed. After the fire was finally out (another story in itself) the driver came up to me and said "Hey the door alarm is still going off." So I investigated and sure enough, for all the truck had just been through, the stupid door ajar alarm was chimming away.

So we had to force open the hood and were able to cut the cables - there was no way that we were going to open the lid enough to disconnect this time. We cut about 2 inches from each cable just to ensure (hopefully) that it wouldn't arc itself and power up again.

[Sta22BeaverCoPA]

Cutting vs Disconnecting Battery
First lets go with the cables, we are going to disconnect the negative side of the battery, not the expensive wire harness. To disconnect the negative side from the battery does give us an option to reconnect/reenergize the electrical system of the car. But in doing this could this possibly tell the DERM (they are now going solid state, no little gold balls)for the airbags that there has been a problem and if they haven't deployed now the airbags do deploy. Remember airbags have deployed due to static electricity, could a sudden power surge or reenergizing do the same thing.
I believe and teach cutting the chunk out of the negative cable (low cost)and work around or through the problems encountered is a lot safer. If you can move the seats, put down the windows prior to cutting then do it. Lets face it, if you can put down the windows and move the seats, then you've already gained access to the passenger compartment and the patient prior to disconnecting the battery, hmmmm did you remember to crib ?

[Fyrechicken]

Disconnect if at all possible, but if you can't access the terminals then I would cut doing the ground wire first then the positive second to minimize sparks

[nutty17]

I believe in cutting the cables. With all the battery locations, types of terminals and such I find it a lot faster to just cut the cable. I certainly look to see if I can operate any power seats or petals before disconnecting the battery but as has already been mentioned previously, you will probably miss something sooner or later. If I missed something I would not try to reconnect the power due to the time involved to monkey a solution. If I really had to move the seat back without power I would simply run the spreaders from the bottom of the A post to the front edge of the seat bracket and spread the seat back. In my experience this evolution done slowly will break the seat rachet mechanism without a jerking motion to the patient although the risk is there so it would be a last used evolution.

[SubarcticFF]

It all depends on the cirumstances. Our priorities are 1) Life Safety and 2) Property Preservation.

If the resources are there (time, manpower, and access) to disconnect, then do so. Cutting will only add more expenses to the owners.

On the same sort of topic, how many departments pull valve stems? I know some departments who don't do it as often because they get hassled by police and tow truck operators (slows clearing the scene).

[bigJ164019]

We cut 100% of the time (as long as there WILL be transport). With the price of battery cables vs cost of accidental discharge of SRS, ect, we err on the side of caution.

[firenresq77]

I personally prefer to cut as Resq14 stated. Just my personal preference.......

[lutan1]

Cut-disconnect, cut-disconnect.

Around and around we go!

Chief, Master, Guru, Extrication God Ron Moore say on page 153 of his second edition Vehicle Rescue and Extrication book-

All negative battery cables should be disconnected or double-cut, after which the positive cables should get the same treatment.

Cut-disconnect, cut-disconnect- WHO CARES!

JUST DO IT AND DO IT SAFELY!

Do as the situation dictates at the time. If you can't disconnect, then cut....

Now I feel better for venting that....

[NB87JW]

If you need to expedite the removal of the patient at a "complex extrication evolution" then you will more than likely cut the cables. If you can "take your time" a little more with the victim(s) at a "simple extrication evolution" then you may take a little more time with the terminals and disconnect them. Provided that, you have easy access. If there is limited access(due to damage or otherwise) to de-energize then the likely choice will be to reach in with one hand and cut the cable(s) in two spots each starting with the negative cable first.

Never say Never, and never say always...

Be safe brothers,

JW