Tesla Model S, Third Fire

[Kremmen]

Sure, the plan may stay the same as it should if nothing changes. However the approval process is for each case separately and naturally you need to implement all the measures for each case separately.
Also, i am sure that environmentalists and various green activists have influenced the processes thereby increasing the cost due to additional safety measures. But i'm OK with that. To maintain balance, every force needs an opposing force. Lest we find ourselves in the situation where the only guidance is the commercial one.

[zapta]

[A while ago one of my customers showed be a big ass lead acid battery which exploded due to forming H2. That got pretty messy as well.

That's was a challenge in conventional submarines, with hundrads of tons of lead acid batteries in a closed environment. They had on the walls small devices called 'hydrogen condensers' or something like that that looked like small heaters and the hydrogen level was routinely monitored. I our terminology, they were 'hybrid', just like the Prius.

[nctnico]

A bit more on-topic: Tesla is recalling all their mains chargers which are installed at the owners. It seems the current charger has no protection against overheating ( -sigh-) :
http://www.cnbc.com/id/101327143

[zapta]

A bit more on-topic: Tesla is recalling all their mains chargers which are installed at the owners. It seems the current charger has no protection against overheating ( -sigh-) :
http://www.cnbc.com/id/101327143

It's not a 'recall', it is an 'upgrade'.  It is not 'required' it is just for 'customer satisfaction'.

That's a very skillfully crafted messaging.

[nctnico]

And it only costs Tesla a few million Dollars. No big deal 

[free_electron]

First off, it is not a 'charger' it is merely the plug at the end of the cable.
Second, there have been four or five of these fires. In each case the wires in the wall overheated, melting their insulation and eventually causing a short at which point the in-house breaker will trip.

But, before that, the house wiring, outlet in its wall box and the tesla provided plug will start melting, releasing smoke and possibly catching fire.

What is the problem ? There are multiple ones
-wrong gauge of wire being used. Too thin. Wire 'ampacity' is one of these whacky definitions that the electric code uses. A 8 gauge wire has this 'ampacity', a 6 gauge a larger one.
Problem is 'ampacity' is defined as allowed current for a given time to prevent damage.

So an 8 gauge may be able to do 30 amp (i am just picking a random number here, i don't know what it really is) but only for 2 hours in a 24 hour period for a longer operation it may fall to 25 amp.
This also changes if it is free wire or wire run in a conduit.

To avoid the potential problem tesla instructs to use the commercial usage ampacity table. That table is for 24/7 loads like ovens in restaurants. You will see that the wire will need to be made a lot thicker.
Since the tesla can sit there pulling power for 8 to 10 hours ....

The same is to be said for the outlet. There are residential grade and commercial grade. Tesla instructs to use commercial grade. These are still using hard bakelite-like self extinguishing materials and oversized copper blades. As opposed to flimsy pressed sheet iron

They give you a nice document to give the electrician with the guidelines on what should be used.

Problem is , people are penny pinching , do-it-yourself installers, or the electricians think they know better and use whatever they have laying around.

And then you get melting wires...

Now, i do agree that tesla should have put a thermal fuse in the plug from the get go. Better safe than sorry.

At least they are correcting it and we will all get a new set of plugs for free.

[SeanB]

Correct, you have to derate for use of a cable in free air to enclosed in a steel conduit to in a plastic conduit to in a conduit with other cables to buried in a wall. Thus a 2.5mm cable can handle 35A in free air, 30A in a steel conduit and 20A in a plastic conduit buried under 30mm of plaster. Thus the rating of 20A for the breaker in a house, and the load is not considered permanent, when it will be derated to 15A. If you want a commercial connection like to an air conditioner you need a 2.5mm cable fed to it, or a 4mm cable for a unit over 30000 BTU normally. Stoves normally have a 6mm cable in a separate conduit, as you can draw loads of 40A for hours doing cooking.

The socket outlets and the plug tops that plug into them are another matter, many are not certified and will fail with full current for long periods, but may work for a few months initially until a few dozen insert/remove cycles weaken the spring tension that allows the contacts to press fit. Often they just rely on the formed brass thin sheet to provide the contact force. Older ones with turned pin sockets had a steel spring to apply force.

[G7PSK]

The main problem with nuclear waste management is the laws governing it were made by politicians shortly after WW2 they had no knowledge of nuclear physics or radiation other than the film taken of the first bomb test and Nagasaki and Hiroshima.
we now have as a result regulations stipulating the disposal of so called low level waste and as to what that waste is. The low level waste includes the waste paper from the offices at places like Sellafield, the envelope from the morning mail opened by the receptionist goes int the waste bin this is then classified as low level waste, I know this as I was involved in the manufacture of a twenty ton container to transport the waste paper low level waste in the early 1990's. This sort of ridiculous regulation needs to be brought up to date.

[johansen]

The permanently installed wall charger can suck up to 70 amps out of the wall...
no wonder there were a number of fires.
code would require 6 awg wire as a bare minimum, i would speculate most inspectors would require 4 awg.

either the terminals weren't tight, or they used 8 gauge wire.
Tesla could put a thermistor inside the terminal block to prevent this "error" but other than that, nothign they can do about it.
70 amps through 40 feet of 8 gauge is only 1.8% voltage drop.

[tom66]

In all instances of overheating, the fault has occurred between the UMC (universal mobile connector?) and the mains socket, or the socket and the wiring.
The permanently installed wall charger doesn't have this problem.

[zapta]

... either the terminals weren't tight, or they used 8 gauge wire.
Tesla could put a thermistor inside the terminal block to prevent this "error" but other than that, nothign they can do about it.
70 amps through 40 feet of 8 gauge is only 1.8% voltage drop.

This is something a smart charger can approximate and adapt to. Consume 1A and measure the voltage, consume 20A and measure the voltage, compute the output resistance of the source and adjust the charging power.

It will not distinguish between a short thin wire and a long fat wire but for household usage it may be a good enough approximation.

[tom66]

It already does this. If it senses a significant drop under load, it limits current to a maximum of 16 amps and charge port flashes orange. Still charges but slower. This is evidenced by a loose connector at the car causing this.

There's no smooth curve, either full power or limited power.

Also has line stability check, to detect intermittent/arcing connectors, but apparently that's causing quite a few false detections.

[nctnico]

IMHO all kinds of schemes to detect faulty wiring conditions are prone to backfiring. A false positive means someone's car is not charged in the morning. Very nice (NOT!) if you want to go on a holiday without enough juice to make it to the first supercharger.

[tom66]

It's supposed to send a message to the app on your smartphone.

[nctnico]

You have to run at the limit. Tesla's supercharger network isn't denser than they deem necessary.

[tom66]

That's why it's a car for people pushing the envelope, GenIII should have more superchargers and possibly a 300 to 350 mile EPA range version giving more buffer.
I think you can reach each supercharger easily in 85kWh and if you hypermile in a 60kWh, but this will eventually change as the network grows.

[zapta]

You have to run at the limit. Tesla's supercharger network isn't denser than they deem necessary.

The Pony Express system had better density and refueling time . Riders swapped their horses every 5-25 miles.

http://en.wikipedia.org/wiki/Pony_Express#Stations

[SgtRock]

Greetings EEVBees:

--Too many piglets and nowt enough teats.

http://www.cbc.ca/news/technology/charge-rage-on-rise-over-lack-of-silicon-valley-car-charging-stations-1.2503899

"All music is folk music. I ain't never heard a horse sing a song."
"If you have to ask what jazz is, you'll never know."
"The memory of things gone is important to a jazz musician"
Louis Armstrong 1901 - 1971
 
Best Regards
Clear Ether

[nctnico]

--Too many piglets and nowt enough teats.

This sounds like nonsense. Why would every employee be desperate to charge at work? Most people just charge overnight at home. I suppose it's free electricity, but it wouldn't really drive you into a rage over it. A simple rota system could sort things out if people are that desperate.

I don't understand how you fail to see that charging at home is not an option for many people  The picture which comes with the article even shows a big apartment building!
Besides that, charging during the day makes best use of wind and solar power.

[EEVblog]

I don't understand how you fail to see that charging at home is not an option for many people 

Then such a person would be a complete fool to buy a pure EV to begin with.

[nctnico]

I don't understand how you fail to see that charging at home is not an option for many people 

Then such a person would be a complete fool to buy a pure EV to begin with.

Why? The whole at home charging idea is just wrong in the long run. The grid feeding domestic areas is not going to cope with the sheer amount of electricity required when many people have an EV. Charging stations are the way to go just like you go to a gas station to get petrol.

[nctnico]

Then such a person would be a complete fool to buy a pure EV to begin with.

Why? The whole at home charging idea is just wrong in the long run. The grid feeding domestic areas is not going to cope with the sheer amount of electricity required when many people have an EV. Charging stations are the way to go just like you go to a gas station to get petrol.

That's ridiculous. If you charge your car overnight it doesn't need a high power charger, it can run from a normal wall socket. Doesn't matter if it take 8 hours. The grid can be upgraded, since we need it to be. This is just a lame, defeatist attitude.

At what cost? It takes Germany billions of euro to connect the solar panels and wind turbines in the north to the users in the middle. Nobody wants to pick up the bill.

You also claim that charging during the day makes the best use of wind power... You know that the wind blows at night too, right?

Not as much as during the day. The sun is the motor behind the wind. I live in the windiest part of the NL  but the wind stops during the night. I actually have to turn on my airconditioning on summer evenings to keep my office cool due to lack of wind.

If you live in a flat and really want an EV just ask the landlord if you can have a charger installed. Most will probably say yes, it's a free upgrade. If EVs are popular, like they are in silicone valley, landlords will install chargers to attract customers. I really don't see why companies find it so expensive to install additional charging points either, since they don't need high power expensive ones.

Do you see the contradiction here? Landlords should install for free and companies claim it is too expensive... Besides that the landlord would need to install a system with dedicated parking spots. That is IF the landlord owns the parking spaces in the first place.
Home charging just isn't going to work; it is a stopgap solution.  All in all it takes much less money to install a dense fast charging network (about 200k euro per fast charging station).

[nctnico]

Try putting a couple of fast chargers along a highway (which is where you need fast charging points). A Dutch company is planning on installing 200 fast charging station throughout the country (so far they build 5). They need 40 million to to that. 40M/200=200k. The cost to rent the land from the government is not low. And then they'll need to run a cable which costs another 60k to 100k alone (you'll be looking at a large bill to get a 50kW connection to your home for fast charging).

So anwer this question: who is going to pay for the charging points?

Just installing outlets isn't going to cut it if people have no designated parking spots (the electricity company would like to get paid and those outlets + wiring don't appear magically over night). IOW: the here has to be some form of subscription & metering. The street I live in has about 200 parking spots. If each parking spot needs a charger you quickly go over 200k. And that is for just one street. In that light it makes perfect sense to spend 200k on a fast charging station than trying to charge at home.

[johansen]

 

Try putting a couple of fast chargers along a highway (which is where you need fast charging points). A Dutch company is planning on installing 200 fast charging station throughout the country (so far they build 5). They need 40 million to to that. 40M/200=200k. The cost to rent the land from the government is not low.

most highways have street lights, or a gas station at most every 10 miles, and if you live in an area where you're more than 30 miles away from civilization, you're probably not going to buy an electric car anyways.
second.. the cost to rent land from the government, for electric charging stations, well, there's your problem right there.

[Frost]

most highways have street lights

But only in the USA
In europe you will find highways with street lights beyond cities
only in Belgium.