Disconnecting Batteries at MVAs

[16fire5 693]

A close friend of mine (no emergency service involvement) had a scary incident while jumping his car this morning. He's a real technical guy but he got a little complacent. Which brings me to the topic. I'm finding that I'm constantly having to correct or stop firefighters while disconnecting batteries at MVA scenes. First too many guys have no respect for the hazards involved in what they are doing. Here's my thoughts.

Have a reason to disconnect. Patients still in the vehicle, fire hazard, anything legitimate is good with me but sometimes the car will be driven away or there are no hazards and no one is in the vehicle.

Use the right tools. I really can't bear to see the haligan used. It really can be a recipie for disaster. The haligan is more than long enough to accidently hit both battery terminals. Which believe me when I tell you is a bad sight.

Accessing the battery. When the car is totaled and all the fluids from the vehicle are now on the highway do we really need to use the forcible entry saw to open the hood and spray the entire area with sparks? I mean I thought that's why we disconnect in the first place to eliminate ignition sources.

I'd love to hear others thoughts on the topic.

[Remember585 815]

Good stuff Cap!

As a general procedure for us, we will make every effort to remove the connections on the battery before making any cuts. When we do have to make the cuts, a simple pair of dikes or other cable cutters does the trick. A suggestion made by one of our Captains a while ago was to take a rubber floor mat (if there are any) and put it on top of the battery before closing the hood, reducing the chance of any metal to metal contact. If we cut a terminal, we will cut out a 1-2" section so the wires run very little chance of making contact again.

I've been to plenty of accidents where the battery has been broken and the acid is spilled - be mindful of where you walk on the scene. You don't want your boots or even your pants to become damaged. (Same can be said for hydraulic fluids too).

A simple thing to remember that I learned in a hybrid vehicle class we hosted - NEVER CUT THE ORANGE CABLES.

[CFFD117 19]

Another thing to keep in mind is depending on the car, the battery may not be located under the hood. BMW places batteries in the trunks of some cars (I believe Mercedes does this as well) , I have also heard of batteries located under the back seats. I keep a pair of medium sized channel locks in my gear, and they work fairly well removing the connections.

[PFDRes47cue 653]

Another GREAT topic for discussion!

Car batteries pose a very large threat to emergency personnel when at the scene of a MVA or even an MVF. The battery acid inside can leak out and irritate/burn our skin and ruin our gear. Batteries can also explode or cause a painful shock. Several years, ago while cutting a battery at a MVA I cut the battery cables with a bolt cutters. However, someone thought it a good idea to have a chain on the bolt cutter to hang it in the cabinet. Well when I was cutting the negative wire the chain hung down and touched the positive terminal resulting in a big pop and flash. Luckily, I was wearing rubber gloves!

I have always been taught to leave cutting the batter wires as a last resort and only if the car is clearly totaled. When possible, I always take the extra few seconds to grab a socket and disconnect the battery properly. This allows the battery to easily be hooked back up by the tow truck driver if needed. It also is one less thing that has to be fixed on the car if it is not totaled. When you do need to cut the battery, it is a good idea to do what Remember585 said, cut a 2 inch section out of the cable instead of just cutting through the cable once.. This minimizes the risk of the cable coming back into contact with the battery post.

I often times see FD's go overboard with the tool selection for popping the hood on a car. very rarely will you need a Partner saw to remove a hood! 99% of the time a halligan will work fine. Even easier, just pull of the plastic grille (if it id not fly off in the accident) and pull the hood release cable...believe it or not this WILL open the hood (unless it was severed in the accident). Often times, the batteries are located close to the quarter panel on cars. This makes it very easy to just pry up the corner of the hood with a halligan to access the batter terminals.

Remember, some batteries have terminals on the top and the side...be careful of all four terminals on these batteries. they are all live!

Stay safe!

[Brenman1988 11]

For my department, it is procedure to atleast diconnect the battery, if not cut it. If there is significant damage, especially to the front of the car, we will cut the cables using the method mentioned above by cutting a section out of the cable to prevent them from touching again. If there is only minor damage and we have the time and manpower, we will take the time to disconnect the cables using sockets. Another thing to remember is not to become satisfied when you have only disabled one battery, there are some vehicles out there that have more than one battery and not always in the same place. So there always has to be a thought that there may be a 2nd battery.

[goon16 155]

fyi .....some dodge and chrysler cars have there battery in the wheel well behind the inner wheel well of the car. I actually have to take the wheel off and the plastic inner fender well to change the battery. This is a real PITA. However they do have a postive connection on the top of the motor so u can jump start it... when i work my side job next i will put up years and models that have the battery in the wheel well for a reference. Helps being a mechanic on the side

[ajsbear 11]

Even after you disconnect the battery it is always good to cover the terminals, duct tape works fine, cheep and you can carry it on your rescue with the tool kit.

[helicopper 1,050]

At least confer with the PD on scene before doing anything non-emergent to a vehicle involved in an accident (I'm not talking about extrication, I'm talking about things like cutting battery cables). If there is a serious injury or death and the possibility of an accident investigation cutting the battery cables may result in the loss of evidence and/or a difficulty in accessing evidence (computers, lights, vehicle settings, etc. More often than not you don't have to do anything to the vehicle especially if the victims are out.

Cutting battery cables does not eliminate hazards from the battery - an overheating battery (at least in aviation batteries) can still explode even if disconnected. A damaged battery can still leak acid even if disconnected.

Many of the things powered by electricity have their own capacitors so the hazard from them is not eliminated by cutting battery cables. Airbags are one such thing.

Another good thing to confer with PD about is whether or not it is appropriate to put speedi-dry down. If they're doing an AI, they may prefer to have the tow service do it so the scene is "undisturbed" for investigative purposes.

Again, all I'm saying is talk with your peers who have a job to do too. If we can help each other out, we should make the effort.

[antiquefirelt 994]

Car batteries pose a very large threat to emergency personnel when at the scene of a MVA or even an MVF.

MVF is a new one by me can you give me an "F"?

[hfd745 8]

I am not only I firefighter but I also drive a tow truck on the side. To often everyone is so quick to cut the battery cables. At many accidents the car could have been easily moved but because the cables were cut it is a much harder task. If your deartment has the right tools it takes 15 seconds to disconnect the wire from the battery terminal. The scene will be safe and if needed the battery could be easily reconnected.

[TCD0415 26]

Another thing to think about is that IF you feel that there is a legitimate need to disconnect power to the vehicle, make sure you won't need it later on. In an extrication, sometimes moving the seat back to the rear stop will gain you alot of extra room for patient removal. With an electric seat, once you cut the Battery Wire, that seat is staying in place. Also, if you need to roll the window down with an electric window, running it down with the motor sure makes a lot less mess than breaking the glass and getting it all over the patient. With these possible scenarios and others, it is usually best to try and "remove" the cable from the battery post like a gentleman, in case there may be a need to reconnect it later. Just make sure it is tucked out of the way and will not re-energize by popping back and hitting the terminal.

[NWFDMedic 58]

At least confer with the PD on scene before doing anything non-emergent to a vehicle involved in an accident (I'm not talking about extrication, I'm talking about things like cutting battery cables). If there is a serious injury or death and the possibility of an accident investigation cutting the battery cables may result in the loss of evidence and/or a difficulty in accessing evidence (computers, lights, vehicle settings, etc. More often than not you don't have to do anything to the vehicle especially if the victims are out.

Great point that I never thought about. It's amazing what a car can actually tell you about its accident these days. My department used to cut the cables of any vehicle with a scratch on it. Fortunately, we've changed that over time.

People were mentioning alternative locations for batteries. Most of our ambulances (type 2) have a battery under the hood and a second under either side of the vehicle, about in the middle. When you think about the hazards a battery can cause, it's really interesting that the batteries are kept so close to either an emergency exit (passenger side) or the fuel intake (driver side). Most modular ambulances that I've seen have a battery cabinet located somewhere accessible from the outside (in our AEV's, it's under the ALS cabinet on the passenger side).

[Monty 35]

MVF is a new one by me can you give me an "F"?

Just guessing - but maybe Fire??

[xfirefighter484x 234]

MVF is a new one by me can you give me an "F"?

Just guessing - but maybe Fire??

Look what key is right below (slightly below to the left) the 'F' key on a standard keyboard...

'C'

Just a hunch...

[ajsbear 11]

There is an inexpensive tool you can buy at any auto supply store that can be used to put around the battery terminal then tightened so it pulls the cable off the post of the battery therefore not destroying anything and the battery can be easily reconnected if need be.

[capt2102 64]

Great point to leave battery in place to be able to roll down windows, move seat etc. And yes, always check with PD about moving car or using absorball. They may want scene photos. As far as disconnecting battery; take the negative terminal FIRST. Just had this discussion the other nite with a younger member of my crew. If you go for the positive terminal first and hit a part of the car body with your tool you can actually weld your tool to the car.

As far as disconnecting the battery, I can recall 3 car/ truck fires I've had that were on the hook of a tow truck comming through my district. The batteries were left connected by another Fire Dept. where the MVA occured and that Dept. failed to disconnect the battery. The damaged car is bouncing around on the hook and a pinched wire from the crash starts the car on fire. Tow truck/flatbed driver looks back and the vehicle on the hook is cooking. My rule is if the car is being towed away disconnect the battery... negative terminal first.

[efdcapt115 1,511]

Great point to leave battery in place to be able to roll down windows, move seat etc. And yes, always check with PD about moving car or using absorball. They may want scene photos. As far as disconnecting battery; take the negative terminal FIRST. Just had this discussion the other nite with a younger member of my crew. If you go for the positive terminal first and hit a part of the car body with your tool you can actually weld your tool to the car.

As far as disconnecting the battery, I can recall 3 car/ truck fires I've had that were on the hook of a tow truck comming through my district. The batteries were left connected by another Fire Dept. where the MVA occured and that Dept. failed to disconnect the battery. The damaged car is bouncing around on the hook and a pinched wire from the crash starts the car on fire. Tow truck/flatbed driver looks back and the vehicle on the hook is cooking. My rule is if the car is being towed away disconnect the battery... negative terminal first.

...negative terminal first....THE most important factor when disconnecting....however I used to tell my driver BW to ALWAYS go for the POSITIVE terminal 1st...as I was always hoping for a POSITIVE outcome...(if ya catch my drift) heh heh

Edit: "sidecutters", which should be a standard tool in everyones' turnout coat pocket, are a very effective tool for working on a battery. not only for cutting the cable (last resort if you can't get the terminal off), but for grabbing and twisting the outside of the terminal connector to pry it off..

[PFDRes47cue 653]

MVF is a new one by me can you give me an "F"?

Motor Vehicle Fire.

There is an inexpensive tool you can buy at any auto supply store that can be used to put around the battery terminal then tightened so it pulls the cable off the post of the battery therefore not destroying anything and the battery can be easily reconnected if need be.

Socket set or open-ended wrench?

[antiquefirelt 994]

Some interesting points being made here. What's the thinking on airbags and passenger safety systems when discussing leaving the power connected and even moving seats? While extrication is a rapidly changing evolution, don't most trainers stress not moving seats while the power is connected due to the potentially damaged SRS or airbags? Many bags may deploy a lesser initial charge due to the seat proximity, but this leaves a second deployment possibility if the seat position is changed and the algorithm is met. Wile this very unlikely scenario, there are no guarantees of how the system has been affected after the crash?

My FD has cut way down on the battery cutting over the last few years. Now we really only cut if there are viable patients within the vehicle, and disconnection is still the preferred method. We specifically do not cut if the only occupant(s) are fatals. For us the battery disconnection has less to do with ignition sources than increasing the odds the airbags and SRS systems are de-energized.

BTW, how many LEO's warn motorists in minor accidents of the dangers of untriggered airbags where there's been damage to the sensor areas? A few body repair people have noted that untriggered or poorly reconstructed bumpers could create a "hair trigger" situation? Anyone actually heard of this happening?

[SRS131EMTFF 471]

I would say that cutting the battery cable is the number one complaint of tow truck operators behind 1. you could have picked a better spot? 2. This had to happen a 3:30am and not between business hours 3. Wheres my coffee?

[PFDRes47cue 653]

I recall hearing somewhere, from someone, at sometime that airbags can still deploy for a few minutes after the battery is disconnected. Is this accurate?

[antiquefirelt 994]

I recall hearing somewhere, from someone, at sometime that airbags can still deploy for a few minutes after the battery is disconnected. Is this accurate?

This is true with many systems. In fact reportedly there were some capacitors in some vehicles that could store enough energy for deployment up to 20 minutes! Clearly why everyone should always follow the stay clear rules when it comes to airbags, though this is becoming far harder as more and more bags are installed in more locations.

Other energy sources such as anything connected to the accessory/cigarette lighter ports are also cited as potential trigger energy problems.

Edited February 1, 2011 by antiquefirelt

[PFDRes47cue 653]

This is true with many systems. In fact reportedly there were some capacitors in some vehicles that could store enough energy for deployment up to 20 minutes! Clearly why everyone should always follow the stay clear rules when it comes to airbags, though this is becoming far harder as more and more bags are installed in more locations.

Other energy sources such as anything connected to the accessory/cigarette lighter ports are also cited as potential trigger energy problems.

Thanks for clearing that up. I have head that things can be power for up to an additional 30 minutes!

[ajsbear 11]

Socket set or open-ended wrench?

Special tool similar but obviously smaller used to pull flywheels etc.

[16fire5 693]

Several years, ago while cutting a battery at a MVA I cut the battery cables with a bolt cutters. However, someone thought it a good idea to have a chain on the bolt cutter to hang it in the cabinet. Well when I was cutting the negative wire the chain hung down and touched the positive terminal resulting in a big pop and flash.

This is why I'm a proponent of using a small tool with a insulated handle. It almost eliminates the posibility of completing the circuit with your tool.

I often times see FD's go overboard with the tool selection for popping the hood on a car. very rarely will you need a Partner saw to remove a hood! 99% of the time a halligan will work fine. Even easier, just pull of the plastic grille (if it id not fly off in the accident) and pull the hood release cable...believe it or not this WILL open the hood (unless it was severed in the accident). Often times, the batteries are located close to the quarter panel on cars. This makes it very easy to just pry up the corner of the hood with a halligan to access the batter terminals.

I think this is the sign of members lack of profiency with the irons. Don't get me wrong it is not easy but you should be able to get it open manually. I have used the bolt cutters on a number of occasions to cut the staple on the hood and then pry it up. One way to become proficient is to use the irons.

Thanks for all the responses I was begining to think I was out of touch. My advice to all the officers look after your members on these bread and butter responses and teach them to do it right. Don't be afraid to speak up how bad would you feel if one of your guys blows up a battery and seriously injures themself because of improper technique in a non emergent situation.

[Remember585 815]

Another point I failed to mention in my first post - if you can't access the battery, TURN THE KEY OFF! It may not solve all of your problems, but it will reduce some of them.

If you have to, another option would be to pull the main or all of the other fuses in the car.

Have options...

Edited February 1, 2011 by Remember585

[Bnechis 3,961]

There is an inexpensive tool you can buy at any auto supply store that can be used to put around the battery terminal then tightened so it pulls the cable off the post of the battery therefore not destroying anything and the battery can be easily reconnected if need be.

Socket set or open-ended wrench?

Battery Terminal Puller

About $15

[PFDRes47cue 653]

Battery Terminal Puller

About $15

I actually have used these before. They work great for top posts. Some side posts do not have enough clearance for the terminal puller. But nevertheless, great addition to any rig!

[goon16 155]

side posts screw into the battery so it might be a little difficult or impossable to use a terminal puller

[ajsbear 11]

Battery Terminal Puller

About $15

Thanks Barry, I was looking for a picture and could not find one. If the weather wasn't so bad I would have gone to the firehouse and taken a picture of the one in my gear.