Slashdot Mirror
Tesla Updates Model S Software As a Precaution Against Unsafe Charging
zlives writes "Tesla Motors has maintained that the most recent fire involving one of its Model S electric vehicles isn't the result of a vehicle or battery malfunction, but the company is still addressing the situation with a software fix, according to Green Car Reports. The California-based automaker has added a software function that automatically reduces the charge current by about 25 percent when power from the charging source fluctuates outside of a certain range, Green Car Reports says, citing the Twitter feed from an Apple employee, @ddenboer, who owns a Model S. You can read the text of the update below."
If electricity is outlawed, only outlaws and Nikola Tesla will have electricity.
Hoist Number One and Number Six.
Here is the actual article, not the article about the article... http://www.greencarreports.com/news/1089292_tesla-updates-software-to-cut-charging-if-wiring-may-be-bad
This is a good thing.
I got the 100Amp High ower Wall Charger with mine, and this puppy needs some serious juice!
When i got the car, i used my old "Welder" outlet in the garage, which supposedly was rated for 30 Amps. Of course noone ever was drawing full load from this for long periods of time before people had EVs.
Even my 30A welder only pulls PEAK 30 amp, and not more than a few minutes at a time.
Once i plugged in the Tesla and charging at 30A, the plug got VERY hot, to the point where i was uncomfortable with it, and i manually throttled it back to 18A.
(My default the car will charge at 80% of the rated capacity, so a 30A outlet would charge at 26A)
I could imagine that if left unattended, and not watched over by a curious EE nerd, this would have ended badly.
For the 100A charger i ran 2Gauge wire (That's about as thick as your average garden hose!)
And even the 2Gauge get's noticeably warm at 80A sustained charging.
In the meantime i have been to many friends and family where i "plugged in" (or helped them install their own chargers) and I've seen some shoddy wiring in garages!
Most people use a Dryer outlet "rated" for 30A, but really only good for ~15.
And then for good measure they throw in a 40A wall plate connector.
The tesla charger only recognizes the plug, and - assumes if there is a 40A plug it can suck 40A out of it.
When that has been DIY installed on top of a 20A wiring..... bzzzz we have a problem!
So, hopefully the continuous line voltage monitoring will help a bit, and protect people from their own shitty wiring!
You're comments are a reason that companies drag their feet on enhancing safety. They could do the right thing to add more safeguards. Then some will take that to mean they were defective in the past, and sue. We're actually creating disincentives for companies to improve. The auto insurance IIS safety standards are one of the few places where we provide incentives for companies to improve. I'm kind of surprised it hasn't caused lawsuits "you sold me an x that wasn't as safe as y". Hmm, maybe CYA causes the car companies to have crash testing as early as possible the product cycle to avoid that.
So the basic idea is that if your power source is terrible (i.e. shoddy wiring in your home), then pulling too much through it could expose that problem via a fire. That isn't a problem with the car, but rather a problem with the substandard wiring. If Tesla merely responds with "it isn't us and isn't our problem", we'll invariably hear of more house fires and the Model S will be blamed.
So they develop a change that detects potentially substandard wiring from the symptom of poor quality power entering the vehicle. It then cuts the draw significantly in that case to reduce the risk of said substandard wiring causing a fire (notice the wiring would still be at fault). Suddenly, because Tesla has released a "fix", their car must have been at fault all along!
This is an absurd level of idiocy and quite frankly, if it continues and eventually sinks Tesla, then we deserve to choke to death on the smog of our own stupidity's making. It's really remarkable how terribly dumb the top of the bell curve is. All evidence points directly toward the future envisioned in the film Idiocracy.
-- "Government is the great fiction through which everybody endeavors to live at the expense of everybody else."
The *proper* fix would be to redesign the charging circuit to continuously monitor feed impedance.
They already do that, by monitoring the voltage drop when the load is applied. That doesn't cover all cases though, because fires are more often caused by high resistance or intermittent junctions. If you get say a 5% voltage drop because of wire resistance it's probably no big deal because the heat dissipation is spread out over the length of the wiring. A similar drop caused by a poor junction might glow because it's concentrated in one spot. I believe that poor junctions often exhibit short term fluctuations because they're loose and intermittent, and that's the additional thing that this software mod looks for.
So they 'fixed' something that wasn't even the problem he's sure because the car logs said so...
Sounds like some bullshit and some backpedaling.
His ego is going to kill tesla...
Could be, but having been on the receiving end of complaints for software-driven hardware, an equally likely scenario is this:
They got a complaint about their car catching fire, and afraid of the PR nightmare this could cause, the top engineers were put on the case to find the problem as quickly as possible and fix it. Meanwhile, someone else was put on gathering all the additional information to feed to engineers/press/etc.
In their digging, the engineers discovered that the charging circuit wasn't really all that robust, and that this COULD cause a charging issue, even if it didn't in this case. With the work and testing already done, they rolled out a firmware update to test if this could be the scenario that caused the fire. The logs then confirmed that this issue wasn't the case, but they had a fully tested firmware update that mitigated other potential charging issues, so they released it instead of just keeping it to themselves.
This kind of thing happens all the time. Although I have also experienced situations where the releasing never happened, as the initial complaint was private and the company never wanted to admit publicly that there was an issue -- in this case, the "fix" was rolled into the next update that was actually supposed to do something else -- it came under "various minor feature improvements" IIRC.
This isn't an issue specific to Tesla vehicles, but it is something that any electric vehicle owner should be aware of and an issue in general for home electrical distribution systems.
The first house I lived in when I got married had the entire house on a single 20 amp circuit (supposedly installed by a professional, but I'm not sure which decade with the tar & cotton wiring I ended up spotting as I went through the attic), and the house I grew up in was only rated with the fuse box for 40 amps (again the whole house, but there were multiple circuits with that house). Even the house I live in at the moment is only rated for a maximum of 100 amps, and I'm not really sure how close to that limit I care to push the issue even though the wiring gauge does look sufficient for those power requirements. I know some new home construction can be rated for as high as 200 amps or more, but it is something to be discussing with contractors when the house is being built currently in terms of planning for potential needs of future power needs. IMHO it really needs to be added into the NEC (National Electrical Code) as assuming something like a stead base power load of 40 amps in a standard socket should be found in a garage or something like that.
That doesn't even get into the neighborhood power distribution systems that would need to be updated in a serious manner if electric vehicles became quite common. It most definitely will become a major issue for electric utility companies in the future if these vehicles become popular.
Tesla actually slowly ramps up the current draw. When I hook my car up to the 80A charger it will slowly ramp up to 40A, pause, then slowly ramp up to 80A (there are two chargers in the car, each rated at 40A). It monitors the change in voltage as it does this.
This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
I hate to break the news to you, but Ohio is out-doing Texas.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
don;t meet his requirements.
His requirements? Try the National Electrical Code requirements, which are legally required by most state and local building codes. A 50A line that can't deliver 50A is in violation, and shoddy wiring like that is a serious hazard, regardless of whether you charge a Tesla with it.
The U.S. has had time to upgrade their infrastructure
Are you kidding? Imagine a power company telling its customers that they're being "upgraded" to 240V service, and therefore all the electrical equipment they have will be trash. Moreover, all wiring, outlets, etc. in their home has to be replaced.
120V is not an "infrastructure problem". The only ramification is a little more copper to wire up a home. 120V comes from the max practical voltage for a carbon filament bulb. Europe, being about 20 years behind the US in large scale electric power distribution, was able to choose a higher voltage, but one that was still limited by the then state-of-the-art in metal filament bulbs. If you were to choose an optimal household wiring voltage today, who knows what it would be. Maybe 350V would be better. Moreover, for large loads where 240V makes a significant difference (e.g. electric range or dryer, CAC, etc.), American homes have 240V lines.