The J1772 charging connector should release when you press and release the trigger button on the J1772 charging connector. If you press and hold the trigger button without releasing then the Tesla J1772 charging adapter will remain in the Tesla vehicle's charging port. If you are unsure you can use both hands after you press and release the trigger button on the charging connector (use your free hand to hold onto the J1772 adapter). The only thing that a 3rd party charging station won't be able to do is open the Tesla vehicle's charging port cover by pressing the trigger button.
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Best home charger?
- Thread starter steph746
- Start date
Midnightsun
Active Member
The
Now that NACS is the new standard and all future EVs in North America will have this built-in in the next year or 2, I highly suggest you get a Tesla NACS unit as it will require no adapters on all future vehicles to come. It's not like you will be changing wall connectors like one may change a car. I assume they will last a lifetime or until they fail and need to be replaced. The big advantage of the Tesla unit is you get the NACS connector and the ability to charge at 48A if you so desire.
The easy way is to press and release the unlock trigger without pulling the cord out from the charge port, this signals the car to release the adapter (tesla blue indicator light will turn blue) however since you released the trigger it is still locked on to the adapter and both come out when you pull it out. To remove the adapter if you want while unplugged from the car, just push and hold the trigger while pulling the adapter out. To open the charge door, just push lightly on the door.
Now that NACS is the new standard and all future EVs in North America will have this built-in in the next year or 2, I highly suggest you get a Tesla NACS unit as it will require no adapters on all future vehicles to come. It's not like you will be changing wall connectors like one may change a car. I assume they will last a lifetime or until they fail and need to be replaced. The big advantage of the Tesla unit is you get the NACS connector and the ability to charge at 48A if you so desire.
Electric vehicle service equipment (EVSE) whether Tesla Wall Connector, Tesla Mobile Connector or J1772 equipped universal equipment have a finite life span. This equipment is subject to physical damage and general wear and tear. The signal wires in the charging cable are small in diameter, may break over time. The high power delivered while charging means elevated temperatures for the circuitry. In general this equipment will exceed the typical warranty period (3 years) but last less than 10 years. Even the top quality brands such as Clipper Creek (now owned by Enphase) are know to fail after a number of years. In general when the charging station fails (outside of the warranty) it is not worth repairing and needs to be replaced. At one time this equipment typically cost in excess of $1000 (before the current inflationary period.) Today's charging equipment costs far less than a decade ago.
Um. If it comes to hardware failing at random, I’m your guy. I’ve shepherded busted and broken telecom gear through FMA more times than I can count. Cables, connectors, circuit boards, lightning strikes, power fluctuations, you name it.
But.. I think I have something to say about the reliability of, if nothing else, the Tesla Wall Connector.
From the top: You're right: Heat is the enemy of reliability. There's this thing called the Arrhenius Equation that, pretty much, says that failures go as the exponential of heat rise. So, take two identical transistors: Run one at 115 C, run one at 85C, and the one at 115C is going to last a lot less than the 85C one.
Going along those lines, then, where is the heat being dissipated in a Tesla Wall Connector? Um. And that's when your argument begins to have some issues.
As it happens, the only thing nominally consuming power in a Tesla Wall Connector (or anybody else's, for that matter) is the little bitty computer board that runs the protocol back and forth between the wall connector and the TWC. This computer board is, very definitely, Not A Pentium. Having looked at it, it looks like a bog-standard microcontroller and a dozen or so other parts. I'd guess that half those parts have to do with getting 5V (or whatever the CPU runs at), and maybe 12V (or whatever the CCS standard runs at) made. the rest are filtering. My opinion: If the whole board dissipates more than, say, 5W, I'll eat my hat.
"But!", people say. "What about that 48A! There has to be high power with that, right?".
Um. Maybe, but probably, not so much. That's a relay, called a "contactor" because it handles more current than your normal garden variety relay. There's a pair of contacts (one for each hot leg, and maybe another for the ground), and these contacts are Physically Large and rated for that current. Contactors in this current range are used all over the blinking place: For example, AC contactors are in HVAC systems for the Big Fan, The Compressor, and what all. One can run down to Ye Local Hardware Supply Store and find dozens of the blame things, rated for somewhere like a hundred thousand to a million operations. With contacts a quarter inch across, made out of Really Good Conducting Material, we're not talking a ton of heat, here.
What actually kills contactors are arcs and sparks. Take ye standard HVAC contactor. Say it's closed, chugging along at 20A or something at 240 VAC, and the thermostat in the house says, "we're warm enough, turn off!". The HVAC gear de-energizes the relay and a spring starts moving the contacts away from each other. So, we get a couple of hundred microns of distance between the contacts and there's 200V present.. and a great big honking electrical motor with Big Coils And Lots Of Inductance. Let's say that at the instant the contacts move apart, there's 20A present and a big magnetic field in the motor. As the contacts move apart, the current tries to decrease, and this is what coils hate: They keep the current going, come what may, and an arc forms, at whatever voltage it takes to keep that current going. (That's inductive kick, thank you very much. ICEs use that to make spark plugs spark.) That arc is surface-of-the-sun hot and will vaporize the contact material, leading to pits and such all over the contact. By the by: Same thing happens with wall switches in your house and the like, which is why wall switches don't last forever, either.
Now, in the above example, all the energy in the magnetic field in the motor has to get dissipated somewhere, and heating up stuff and making that arc is how it happens. And, if one doesn't make allowances for this kind of behavior, contactors wouldn't last any length of time at all. There are things, like snubbers (an R-C network across the contacts) that can reduce the arcing, a lot, and dissipate the energy in the Resistor of that R-C network. That reduces, but doesn't eliminate the arcing; and this is why HVAC contactors tend to get replaced every dozen or so years or so.
But.. this is a Tesla. Or some other BEV. Suppose the Tesla gets itself charged up using all those handy rectifiers and switching transistors inside the car. So, now its full. It kinda turns off the current On Its Own, No Inductive Kick, Thank You Very Much. And then, and only then, does it tell the Wall Connector to disconnect the power.
Um. No current is flowing when the contactor is ordered to Open Up. There's voltage, sure - but if there's, like a couple of hundred thousand Ohms of resistance, there's Not A-Gonna Be An Arc. No Arc, No Wear. And that garden-variety contactor, made in its millions for the HVAC trade and dead cheap as a result, is going to last a llloooonnnngggg time. 50 years, maybe? Well, it is mechanical, it's moving back and forth, there's a spring and all, so I guess a little stress and strain will eventually lead to some metal fatigue. But these things are designed to last 10, 20 years in the presence of contact pitting, and we ain't got none of that.
What about other sources of heat? Well, the heavy wires from the breaker panel are connected to joints, and the joints are supposed to be torqued down good and proper. To my eye.. what the heck is going to wear that out?
Now, lets talk about the obvious place: The NACS (or J1772 connector, I don't care for the purposes of this discussion.) I've had a look at the NACS. Those are great, big, huge, silver contacts with lots and lots of surface area. No arcing, for the same reason that the contactor doesn't have arcing. The control pins are pretty blame hefty for something carrying a milliamp or three, with tons of surface area there, too. But, things slide; dirt gets in there; oxidation happens, especially with silver.. So, sure, 15 or 20 years, maybe 10. Sure and begorrah, this connector is tons better than a NEMA5-15. It's clearly designed to be a high-usage connector.
Actually, if there is a place that looks like a possibility, it might be the cable, itself. All metals, when flexed, will eventually succumb to metal fatigue. I've had old extension cords or lamp cords fail this way; an 18GA multi-wire with, say, 8 or 9 smaller diameter wires in there, will, over time, start breaking the smaller wires in different places. Eventually enough of the wires break and the lamp cord or extension cord gets intermittent, the light flickers all the time, the cord might get hot, and it's time to either ditch the extension cord or replace the lamp cord.
It's for this reason that test probe wires, like ones might find on a voltmeter, are Very Thick and have tons of extremely fine wires. Those wires are flexed all the time and wrapped in small diameters around things as they get tossed in and out of drawers. By making the wires ridiculously fine, the amount of bend on a given wire is reduced; but, again, I've had to ditch old test probe wires.
But take a gander at that big honking power cable attached to the TWC. It's.. stiff. Not flexy-wexy. And that's not because of the copper in there, at least not completely: It's because the people who designed that cable put insulation and fabric in there to make it stiff and hard to bend. The harder it is to bend, the harder it is to bend the copper, and so metal fatigue is reduced. That's not a short life cable, there.
Will it fail eventually? Sure. But just how many cycles will the TWC in an average person's home get used? Once a day? 365 days a year? Betcha the designers took that into account.
So, maybe 5, maybe 15 years. And, when it fails.. buy a new cable.
So, I'm guessing that the average homeowner is going to get on the order of 20 years out of a TWC.
What could break this rough analysis?
Well, right off, under-specifying components. Let's suppose that the TWC converts from 240 VAC down to a regulated 15V, which is then used directly by the drivers for the CCS. Use an analog regulator to drop the 15V down to, say, 3.3V to drive the computer board and the contactor windings. Spend a little money, keep the packages the right size, and, if one gets a 10C rise in temperature anywhere, One Did It Wrong.
But! Might be a few pennies cheaper to buy a smaller part that can't dissipate 100 mW properly. (And, yeah, engineers get picked on about a couple pennies per part, when one is building a million of something.) So.. cheap out, use substandard parts from questionable suppliers and, sure, It Won't Last.
As I mentioned, I work in Telecom. Standard practice is to give Telco's 15 year warranties. If you want a fifteen year warranty, then you pay for that - with more expensive, more reliable parts. You guys want to know where the cheap parts are? On stuff that's expected to last five years or less. Like cell phones. In particular.
The other place where solid, reliable parts are used? Cars, no kidding. In many cases, automotive spec'd parts are better than MILSPEC, because car companies really don't want to have to contend with warranty and/or safety repairs.
Conclusion: I wouldn't worry about a Tesla-designed Wall Connector too much. Tesla's engineers have a rep for good, reliable engineering. Can't speak for anybody else.
What about lead-free solder? Consumer electronics now use lead-free solder that is known to develop micro fissures after ~10 years. This affects everything electronic including the circuit boards in an EV.
Also, you won't necessarily want a 10 year old charging setup because it will be lacking some desirable features, i.e. vehicle-to-grid, etc.
Also, you won't necessarily want a 10 year old charging setup because it will be lacking some desirable features, i.e. vehicle-to-grid, etc.
As it happens, I haven't run into fissures with solder, so can't comment on it. I have run into dendrites and tin whiskers. The dendrites were caused by early versions of lead-free solders, discovered in the 1990's by NASA and others and, to my knowledge, have been solved by modern solder formulations.
Tin whiskers, it turns out, happens when one galvanizes things. But they sure as heck can be invisible to both the naked eye and an eye and a ridiculously high-powered optical microscope
.I did a quick web search on the micro fissures; what papers I skimmed seemed to be talking about issues with nanoparticles embedded in the solder paste. After soldering, over time, slow reactions on Really Thin layers of solder apparently cause opens. I'm not sure that this is the issue of which you speak, but it looks likely.
However, I can see this as an issue with dense wiring on a circuit board with lots and lots of connections.. like, say, with a cell phone or tablet. With 'way less than a mil wide traces and connections, things get interesting.
But, going back to that TWC whose circuit board I took a gander at: There weren't that many connections; the board wasn't particularly strained for space, and the leads on the board were clearly visible and not particularly dense, which makes sense for Ye Basic Microcontroller Setup. Under those circumstances, one can make the traces a lot wider, say, 10 mils or bigger, and one doesn't need to use chips with 150 BGA pins under them, shrunk to the smallest size achievable. So, everything is wider and thicker - including the solder. So, as a random guess, given the 3"x4" or so board I saw in there, it probably isn't susceptible to that kind of fault. It's less, "Consumer electronics" and more, "Industrial Electronics".
So, don't think that the Tesla TWC has this issue. If I get ambitious, I might take the cover off my TWC and take a couple of pictures of the board to get an idea of the technology involved.
