Tesla won't charge with mobile charger

[Tronguy]

Yes. I’ve tried to use Quick240 devices in the past and they usually don’t work. Major hassle finding non GFCI circuits on opposite phases. In this era of ubiquitous Superchargers, it just isn’t worth it to save 20 minutes at a Supercharger.

So, GFCI is an impediment to getting a Quick240 device to work; I get that. But I have two other points about this Quick240 device.

• It violates the KSS principle: Keep it Simple, Stupid. Complexity is the enemy of reliability. I'd rather have something relatively simple like a breaker than some complex current-measuring widget with a lot more parts and possible failure mechanisms. And, for what it's worth, breakers themselves are the kinds of things that can die with age and manufacturing defects. I've messed with breakers (mainly, with sizing them) but one gets the impression that there are lots of standards about how they work and how reliable they are. This Quick240 device.. think that it's gotten the same attention over decades?
• There is a reason to have a home charging system: It's a heck of a lot more convenient and probably cheaper over time than using a Supercharger. Superchargers tend to cost around 3X the cost of electricity at a house, since, beyond the cost of electricity, they need maintenance, repair, and the cost of financing Even More Superchargers. So, fine: Put a 240 VAC charger in one's house if one can swing it. But if one is going to do that, following the KSS principle and Doing It Right is the way to go.

One last whack at this, then I promise to shut up (on this thread) about the topic: There's lots of things that can go wrong with electricity. Worn wires, bad manufacturing, things cutting through insulation, connector plastic failure, cracks in plastic, cracks in metal, corrosion, transistor die failures, circuit board failures, microprocessor failures (both hardware and software/firmware), cosmic-ray induced bit flips in RAM, and it just goes on and on and on.

Tesla does a pretty good job trying to shut things down with software; we all know that if there's an excessive voltage droop, or there's not a proper connection to ground/neutral, etc., the software will shut down charging.

But there's always stuff that software simply can't touch. Serious people with PhDs and such have had at the problem when insulators don't, conductors don't, stuff breaks, and so on, and from this comes things like the NEC and what seems to be the near-infinite number of standards on things people wouldn't normally consider as a potential problem.

Were you guys aware of nifty things like Y and X rated capacitors? Y rated capacitors are designed to go between a hot and ground/neutral. One of their defining characteristics: When they fail, they fail open. Repetitively, even. That.. isn't trivial to do. X rated capacitors are designed to go across a power feed; they don't necessarily fail open, but they are designed to Not Catch On Fire if they fail short. That last, of course, being something that capacitors do.

So: Electricians get trained on electrical safety. They don't take short cuts, or are sure not supposed to. (One can find somebody flinging $BS in every profession.) Homeowners can do electrical work, too, and can do it right, given the chance. But all of this leads to Why Building/Electrical inspectors and permitting: Another pair of eyes to look for mistakes. Since mistakes can kill people, this is a Good Thing.

And that's enough for the day.

 

[Rocky_H]

I have one of the official name brand "Quick220" devices that has all of the sensing and safety stuff. It's just not useful. There are almost never any situations in which you can actually put it to use. It can't work on GFCI circuits, and guess what? ALL outdoor or garage outlets are required to be GFCI. So it's only possible to use it from stringing really long extension cords from outlets in interior rooms.

 

[davewill]

I've messed with breakers (mainly, with sizing them) but one gets the impression that there are lots of standards about how they work and how reliable they are. This Quick240 device.. think that it's gotten the same attention over decades?

I almost hate to post this, as I'm not in favor of their use, either, but the Quick220 is tested and listed by Intertek to UL and CSA standards, so it has definitely had some thought and ongoing review put into it's safety. Probably at least as much as your average EVSE has. Probably a lot more than your average China cheapo EVSE.

Of course, they all rely on being protected by circuit breakers and such, like any appliance. If I had two compatible, convenient outlets of good quality, I wouldn't be scared to use one as a temporary solution, but that is almost never the case. Like @Rocky_H pointed out, people end up using random extension cords snaked through windows or propped open doors, plugged into 20yo outlets.

Using one as a temporary solution where you can check all the connections carefully is one thing, using one as a daily charging solution however, is a ridiculous and unwarranted risk. There are too many plugs to work loose, or be tripped over, circuits that can become overloaded because someone unwittingly plugs something in, etc...

And there are plenty of fly-by-night suppliers of such hardware (and DIYers who cobble their own) who are not so careful. It's a solution whose time is very long past.

 

[MOE J]

Man, these cold issues need a huge fix: insulate the battery, insulate the undercarriage and install a better bat-warmer.

Also-the superchargers-they too need a winter overhaul (insulation/charger warmer).

How about an Over the air update fix--lets go tesla engineers/IT techs

 

[Rocky_H]

Man, these cold issues need a huge fix: insulate the battery, insulate the undercarriage and install a better bat-warmer.

Well, what this thread is about is someone trying to use an eye dropper to fill a swimming pool, and then you're here saying the swimming pool is what needs the update so it fills faster. That's not the problem. There is a battery heater that can do its job if you give it enough power to really do it.

Also-the superchargers-they too need a winter overhaul (insulation/charger warmer).

How about an Over the air update fix--lets go tesla engineers/IT techs

The notorious stories from Chicago are more of a two-fold thing of driver education and construction. More sites with more stalls are needed, because this warming just takes a large amount of time. So making sure more cars can get plugged in while they have to be connected longer requires capacity.

 

[M CARLING]

Regarding the Quick220. Each leg is protected by a single pole 120V circuit breaker. If either one of those circuit breakers trips, then all current stops flowing through the Quick220 to the TMC, not just half the current. So the breakers not being ganged together isn’t optimal, but it’s not a disaster either. The residual danger is that if one of the breakers trips, then the other leg is still hot (despite no current flowing). A naive user trying to find or understand the fault might become the conductor between the hot leg and neutral or ground. Despite that quibble, I agree that they are not safe enough for regular use. I might use one in an emergency situation, but I would watch it. I certainly wouldn’t go to sleep with one plugged in (operating or not).

If the problem is a very cold garage and there are two 120V circuits available (whether on the same or different legs), I think a better solution would be to plug the TMC into one of them and a 120V space heater into the other one.

I agree with all the posters that 120V is not sufficient for very cold weather charging. Install a 208V or 240V or 277V charging solution if possible. If you’re in a single family home in North America, 240V would most likely be available. If you’re in a complex of townhouses, for example, or another multi-unit complex, you may have 208V available. It’s very rare to find 277V available residentially. 277V will charge faster than 240V which will charge faster than 208V, but any of them will be much, much faster than 120V. Note that TMC works fine with 208V or 240V (which share the same receptacles), but there are no adaptor cords available for 277V receptacles. A hard-wired wall connector is required to charge from 277V.

Finally, if all you have is 120V available and it’s so cold that the car isn’t able to charge from it, leave it plugged in. Insufficient current is better than zero current and might save your battery from being damaged.

Using the car’s cabin heater is likely to be counterproductive. The battery heater is a much more efficient way to heat the battery than the cabin heater and they would be competing for very limited electricity. Every watt hour used to heat the cabin would not be available to the battery heater.

 

[davewill]

Regarding the Quick220. Each leg is protected by a single pole 120V circuit breaker. If either one of those circuit breakers trips, then all current stops flowing through the Quick220 to the TMC, not just half the current. So the breakers not being ganged together isn’t optimal, but it’s not a disaster either. The residual danger is that if one of the breakers trips, then the other leg is still hot (despite no current flowing).

Not so. If one of the breakers trips, the Quick220 will disconnect both legs from the output receptacle. It has relays that only energize if both legs are present and on different phases.

 

[Rocky_H]

Regarding the Quick220. Each leg is protected by a single pole 120V circuit breaker. If either one of those circuit breakers trips, then all current stops flowing through the Quick220 to the TMC, not just half the current. So the breakers not being ganged together isn’t optimal, but it’s not a disaster either. The residual danger is that if one of the breakers trips, then the other leg is still hot (despite no current flowing). A naive user trying to find or understand the fault might become the conductor between the hot leg and neutral or ground.

No, that's not true. That's what makes the Quick220 (TM) an actual product instead of just some cords screwed together. It is better and more expensive because it has real detection and safety mechanisms in it. It senses for both sides being live and connected before it will allow that on the output. If either side gets disconnected, it shuts off and displays an error warning light.

 

[M CARLING]

I should have been more careful with my wording, but we’re all correct. I didn’t write that the Quick220’s receptacle (or any part of it) is still hot. I wrote that the leg is still hot — and it is — all the way from the breaker in the panel (which is where it ideally would be shut down) to inside the Quick220. As I wrote before, “not a disaster” but it’s not as safe as a ganged double breaker. Again, as I wrote above, it’s only a problem if a naive user starts poking around trying to figure out how and why it shut off.

 

[Rocky_H]

I didn’t write that the Quick220’s receptacle (or any part of it) is still hot. I wrote that the leg is still hot — and it is — all the way from the breaker in the panel (which is where it ideally would be shut down) to inside the Quick220.

So....you're describing the power cord of your television. It is supposedly dangerously hot because the inside of the cord is connected to the outlet all the way from the breaker in the panel to inside the TV.

It would only be "hot" in the exact same way that a plain old extension cord with nothing plugged into it is "hot" just because it is a physical extension of the wire in the outlet. The only hot part is inside the cord where people can't touch it, so it's no different than any appliance cord.

So why should that be "ideally shut down"? There are no exposed metal prongs that are hot, which is the problematic thing that can happen in a kludged one of these that doesn't have the safety monitoring.

You're trying to ridicule this as not safe when that's not the case. It is safe; it's just not very useful.

 

[rrolsbe]

This is a frequently reported problem with 120V charging in the cold. It provides so little power that power taken up trying to get the car warm enough to charge is more than the 120V outlet can provide. If it is cold enough, the car actually drains battery instead of charging, as you found out.

If you have a garage, it would help to warm it up. If you have a space heater, that might help too.

I'm not entirely sure if running the cabin heater really helps you, as the battery pack is what needs to warm up.

Try to get a 240V option installed as soon as possible. If you have an electric dryer, using that port may work in a pinch. If you have a NEMA 5-20A outlet, that might also help squeeze a little bit more power, although you need the Tesla 5-20 adapter.

I have never been in a position to test 120V/12A charging with a very cold traction battery. Given a 2018 Model 3 RWD can send 4kW of energy to the rear motor stator winding for battery heating, is the car not smart enough to only use available power from the wall 1.4kW and not ALSO use an additional 2.5kW from the battery? Sounds like it may not be, so owner beware?

 

[DuncanM]

I have never been in a position to test 120V/12A charging with a very cold traction battery. Given a 2018 Model 3 RWD can send 4kW of energy to the rear motor stator winding for battery heating, is the car not smart enough to only use available power from the wall 1.4kW and not ALSO use an additional 2.5kW from the battery? Sounds like it may not be, so owner beware?

There's a number of issues being discussed including why the OPs charge current is dropping to 8a. As I mentioned earlier if your 120v outlet is fed with 12-2 wire and a 20A breaker, you can change the outlet to a (get a high quality outlet) NEMA 5-20 to charge at 120v/16a. I have charged at 120v/12a at ~0F and the car will charge but the battery will lose a few % SOC, at the end of the session, when scheduled preconditioning the cabin and battery is turned on.

 

[Rocky_H]

is the car NOT smart enough to only use available power from the wall 1.4kW and NOT ALSO use an additional 2.5kW from the battery? Sounds like it may NOT be, so owner beware?

I'm normally pretty good with following these, but you've got three negatives in here, so I didn't follow which way you're asking this or if I should answer yes or no.

 

[M CARLING]

So....you're describing the power cord of your television. It is supposedly dangerously hot because the inside of the cord is connected to the outlet all the way from the breaker in the panel to inside the TV.

It would only be "hot" in the exact same way that a plain old extension cord with nothing plugged into it is "hot" just because it is a physical extension of the wire in the outlet. The only hot part is inside the cord where people can't touch it, so it's no different than any appliance cord.

So why should that be "ideally shut down"? There are no exposed metal prongs that are hot, which is the problematic thing that can happen in a kludged one of these that doesn't have the safety monitoring.

You're trying to ridicule this as not safe when that's not the case. It is safe; it's just not very useful.

The difference is that the power cord to the television is only hot when everything is working correctly. When there is a fault, a circuit breaker trips in the panel and the television’s power cord is completely de-energized. That’s not what happens with Quick220. When there is a fault with Quick220 or the device that’s plugged into it, one of the two circuit breakers in the panel will trip, but in nearly all cases, the other breaker will not trip and its leg will remain energized. The Quick220, sensing voltage on only one leg, will then de-energize its receptacle. That’s probably safe enough for users who aren’t idiots, but it’s not as safe as de-energizing both legs all the way to the panel, because that’s what many people will expect to happen when it shuts down following a fault and a breaker trip.

When a fault has occurred, some people who think they understand more than they really do will poke around trying to understand what happened. You and I understand that the Quick220 has internally de-energized its receptacle and is hot inside. Some users might expect it to be de-energized all the way back to the panel and start poking around, possibly where it is plugged in, possibly trying to look inside the Quick220. There are some really stupid people in the world. I once dated a woman who thought all dogs are male and all cats are female and together they produce mixed litters of male puppies and female kittens. I probably wouldn’t worry too much about her around a Quick220 because she doesn’t know enough to be dangerous i.e. she doesn’t think that she knows more about electricity than she really does. However, there are guys out there whose ideas about electricity are just as wrong as her ideas about dogs and cats. There are reasons why 240V split-phase breakers are double ganged. It’s to increase safety.

A lot of linemen have been hit hard touching distribution lines (2400+ volts) that have been de-energized and verified to be de-energized (using a mega) because they didn’t understand induction from parallel lines. A de-energized distribution line has to be clamped to neutral (or ground) before it’s safe to handle — even with suitably rated and properly tested PPE. These are guys who work with electricity day in and day out and go through mandatory safety training every year. Linemen still get electrocuted from time to time. Thinking something is de-energized when it isn’t, whether it’s a 24,000V volt overhead line or a 120V line from the wall to a Quick220, does not enhance safety.

I didn’t write that Quick220 is not safe. I wrote that it’s not as safe as a double-ganged circuit breaker. I stand by that opinion. I also didn’t in any way at all ridicule Quick220. I even wrote that I would use one in an emergency. That’s the opposite of ridicule.

Again, I should have been more clear in my first post. I thought I corrected that in my second post, but perhaps not well enough.

 

[rrolsbe]

I'm normally pretty good with following these, but you've got three negatives in here, so I didn't follow which way you're asking this or if I should answer yes or no.

Yeah, not my most concise forum post but two late to edit.