drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Still is.
EV's in Parking Garages
- Thread starter gadfly56
- Start date
drcampbell
Senior Member
- Location
- The Motor City, Michigan USA
- Occupation
- Registered Professional Engineer
Still is.
How many time has a carpenter, mason or plumber on a jobsite told you "No thanks; I prefer hazards I can see."?
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Most times I get the opposite from GC (I can do everything type) "It's only 120/240. What's the problem?" and "Lights come on so what's the problem."
brantmacga
Señor Member
- Location
- Georgia
- Occupation
- Former Child
the only thing I can say that I've noticed is that EV charging seems to always be at the entrance to the structure; never above the 1st floor. I'm not sure I'd say that's by design due to fire concerns, but likely the least expensive place to run power, and many times these stalls are "sponsored" by a local EV dealer. Not a thing where I am, but several parking garages in Atlanta have EV stalls "courtesy of.." Polestar or Tesla.
But being at the entrance would shorten response time for the FD.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Just a couple of observations:
The fire protection at a gas station is far more extensive that the fire protection in a parking garage for ICE cars. Lots more fuel available, greater change of spills, etc.
The fire issue with a parked EV, a slow charging EV, and a fast charging EV are probably all different.
An EV charging system offers the opportunity to stop the charging in the event that a fire is detected.
I don't have enough information to discuss further, but would hope that an insurance company is actually gathering statistics!
-Jon
The fire protection at a gas station is far more extensive that the fire protection in a parking garage for ICE cars. Lots more fuel available, greater change of spills, etc.
The fire issue with a parked EV, a slow charging EV, and a fast charging EV are probably all different.
An EV charging system offers the opportunity to stop the charging in the event that a fire is detected.
I don't have enough information to discuss further, but would hope that an insurance company is actually gathering statistics!
-Jon
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I've never experienced an EV. Are these free chargers or do they all require credit/debit cards?
If the latter, how does the cost-per-mile compare to charging at home?
If the latter, how does the cost-per-mile compare to charging at home?
Some are free, some are pay to play. The pay to play are almost always more expensive than charging at home.
The only public level 2 chargers in my small city are in the parking lot of our hospital. The rate is $0.39 per kWh. My home rate is between $0.13 and $0.139 depending on how much I use.
The ones at the hospital are, for the most part, only used by visitors from out of town.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
The problem with EVs catching on fire is not a problem the electrical code can solve. I can only imagine the conflagration that will one day occur in a parking garage with hundreds of EVs that catch on fire because one of them does and it spreads. At present there is nothing that will stop the spread of the fire and for the most part automatic water sprinklers make it worse. The fire dept cannot stop it either so a single car fire could easily take down any building. The only real answer is not allowing EVs in a parking garage. Even if the chance of any individual EV catching on fire is pretty small, the way large numbers works means it will happen some day and it will take down a building.
With IC engines, a fire in one car can be readily extinguished and do minimal damage to the rest of the vehicles or the structure.
With IC engines, a fire in one car can be readily extinguished and do minimal damage to the rest of the vehicles or the structure.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
A particular problem with the typical EV battery fire (fully involved) is twofold:
1. The energy stored in the battery is high and, at least initially, can be discharged faster than a fuel fed fire. And you have both the stored energy and the one-time energy of combustion of the active materials.
2. The active materials of the battery cells are under a floor pan and still at least partially enclosed within the deliberately strong battery housing. And further isolated by the cell casings themselves.
Both of these combine to produce a fire which is hard to extinguish (when you cannot allow it to just burn out). The main initial effect of the applied water is to cool the materials, but this is made more difficult by the protection around them. I have seen estimates that a Tesla battery might require 40,000 gallons of water if fully involved. By comparison, the typical fire engine has 500-1000 gallons on board, a dedicated water tender maxes out at 4,000 gallons and a typical ICE fire can be extinguished with 200 gallons of water. Less if foam is used. Foam is of no use for an EV battery fire.
On the other hand, as the technology evolves, specialized equipment is being developed for EV fires which is also able to navigate the low ceiling of a parking structure. The Coldcut Cobra (TM) system uses a high pressure (4,000+ psi) water jet containing abrasive material (essentially a water-cutter) to penetrate the car floor pan and the battery itself, extinguishing the fire with as little as 64 gallons of water.
Once this type of equipment is deployed in a city, either in the form of a specialized engine or a trailer mounted system, extinguishing an EV fire will become routine.
In the meantime, I can see insurers requiring locating EV chargers with space or barrier separation from other vehicles and a nearby high volume fire hose connection to mitigate the risks.
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
Fast charging really stresses and shortens battery life, how about only allowing standard chargers in confined spaces ?
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
So when I have a 3 hour commute into the city center for a 2 hour meeting, I will only be able to have a standard charge before I finish the rest of my day?
mtnelect
HVAC & Electrical Contractor
- Location
- Southern California
- Occupation
- Contractor, C10 & C20 - Semi Retired
There have been many complaints from EV owners that a high percentage of those "Fast Chargers" don't work as advertised anyway.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I recall reading somewhere not too long ago that at least some of the recharging stations do not have the supply capacity to have all the chargers running at full load simultaneously so some chargers have to be shut off or limited in some way.
Around here there are a bunch of charging stations but I cannot recall ever seeing a car plugged in.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Is halon an effective battery extinguisher? Maybe something on-board?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Halon and other halogenated hydrocarbons are getting much more highly regulated as strong greenhouse gasses.
The effectiveness of Halon is probably limited as it will do no cooling and may not actually get to the combustion sites within the battery.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
We are increasing the hazard classification and design densities.
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
And I strongly suspect that the incremental increase in flow rate of fire sprinklers will not make a large difference.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
Sprinklers have been found to be very effective in suppressing fires in ICE vehicles in parking structures. "Suppress" meaning it keeps the fire from spreading to adjacent vehicles and allows time for firefighters to get on scene and plan their response.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Yep. Sprinklers are good for cooling things down and limiting the spread of fires.
The thing is I think most places parking structures are not even required to have sprinklers at all. Which is not a bad bet on things since parking structures tend to be largely made of non combustible materials.
But normal sprinklers will just make lithium battery fires worse.