The Electric Vehicle Thread

[RobLJ]

If you can find one before March, it looks like they will qualify for the $7500 tax credit, although the battery sourcing requirement will probably change that in March.

If you can find one, it's a great deal.



It costs me 8.50 (at .13kw) to charge mine for a 230-300 mile range. The Forester it replaced would require at least $35 for that, although that's at 3.50/gallon for premium which is selling for about $4.50 right now here in Reno.

Like I said before, that $25k will also get me a used Bolt in the not-too-distant future...I don't know why everyone focuses on Tesla EVs.

I'll add a 240VAC outlet on the front of my place (using the electric dryer circuit) to charge it at my (24/7, all-in) cost of only $0.10/kWh.

Doing that & avoiding ($$$) Level 3 chargers will mean a per-mile fuel cost of ~1/3 that of gasoline.

As for outages, I've lived in the same place for almost 30 years & hurricanes damaging refineries in the Gulf of Mexico have resulted in more gasoline shortages here versus the few noticeable electric outages (longest less than a day) that have occurred in all that time.

 

[Rustic23]

before putting in a diy home charger, be sure to look at this video! Nothing to sell, but it seemed like good advice. I never thought of it.

https://youtu.be/tDp9PhPJhUI

 

[REWahoo]

before putting in a diy home charger, be sure to look at this video! Nothing to sell, but it seemed like good advice. I never thought of it.

https://youtu.be/tDp9PhPJhUI

Although listening to Sandy Munro is like fingernails on a chalkboard to me, the video does make some good points. There are way too many YouTube videos out there with DIY instructions for installing an EV charging circuit, and this video shows what can happen even when you have a "pro" do it.

Key takeaways for me from this video and the other "my charging circuit melted" reports I've seen is 1) have an electrician do the install, 2) use high quality components, and 3) use the minimum amperage setting on your charger to get the job done. I have a 50 amp circuit but charge at 32 amps to reduce the potential for overheating.

One other safety measure is to place a remote sensing thermometer with an overheat alarm on the charging receptacle. Since I charge at night when rates are lowest, the thermometer will set off an alarm on the base unit in our bedroom should the temperature of the receptacle/plug overheat.

 

[Koolau]

Although listening to Sandy Munro is like fingernails on a chalkboard to me, the video does make some good points. There are way too many YouTube videos out there with DIY instructions for installing an EV charging circuit, and this video shows what can happen even when you have a "pro" do it.

Key takeaways for me from this video and the other "my charging circuit melted" reports I've seen is 1) have an electrician do the install, 2) use high quality components, and 3) use the minimum amperage setting on your charger to get the job done. I have a 50 amp circuit but charge at 32 amps to reduce the potential for overheating.

One other safety measure is to place a remote sensing thermometer with an overheat alarm on the charging receptacle. Since I charge at night when rates are lowest, the thermometer will set off an alarm on the base unit in our bedroom should the temperature of the receptacle/plug overheat.

All good advice. I wonder how many folks know about this issue. My son has a Mod 3 and he seemed to think charging at home was a no brainer though I have no idea who installed his charging system. I will mention this to him and thanks to Rustic23 for the source.

 

[JoeWras]

I skipped a bit through, didn't see it all, but saw some interesting items. Start with what REWahoo said, and I'd add:
- Connectors need to be approved for heat and long duty cycle applications.
- Consider a load balance switch that turns off the charger circuit when the draw in the rest of the house is high.

They talked about how the typical dryer plug is soft plastic, as it is rated for occasional use. 100% duty cycle may overheat it. Quality connectors cost a lot more, and may use old fashioned material like Bakelite. That's intentional for heat.

The load balance switch was to protect the main panel and prevent it from experiencing long periods of high draw. Just in case.

The electrician guy kind of ranted a bit on the fact that NEC needs to come up with better standards for this application. It simply is nothing like any other application in a residential home. Stoves, dryers, A/C units all have duty cycles allowing rest and heat dissipation.

Sandy mused that maybe some of the Bolt fires were due to bad charger installs instead of the car.

 

[Midpack]

^^ +1. I am using one of the most expensive NEMA 14-50 receptacles you can buy, Hubbell or Bryant - they cost about 10X that of a Home Depot e.g. Leviton or cheap generic, what most of us probably have for our home clothes dryers. I am also using a top of line 50A breaker, but I will charge at 32A or maybe lower - that's way faster than I would ever need, pushing for 40A or higher just isn't necessary to me. I will charge over night, during off peak times, even though my electric utility charges the same rates 24/7 (inexplicably). Trying to save money with the cheapest home garage EV 240V charging setup is literally playing with fire IMO. Tesla provides instructions for a safer, robust installation.

https://www.tesla.com/sites/default/files/downloads/universalmobileconnector_nema_14-50.pdf

 

[joesxm3]

Well that was enough to scare me. I bought the Tesla Wall Charger and was going to send it back today and go with the NEMA 14-50 plug. But I think I will stick with the wall charger so at least that piece ought to be up to the task.

I saw another video where they decided to use 4 gauge wire instead of the recommended 6 gauge. That might be worth the extra cost. I just checked the manual and it says "minimum 6 gauge".

What is a "fire rated wall"? I am planning to mount the charger to the cement outer wall in my cellar/garage. From a quick Google it seems that the cement wall qualifies.

The part that lost me was when they talked about a "bolt on" circuit breaker separated from the other breakers in the box and using a "knife cutoff" switch.

I don't know much about breaker panels.

I know that I have a 200 amp service coming into my panel. I think that there is some sort of a "bus" that the individual breaker circuits are connected to.

Does this mean that all the breakers feed off the one "wire" (for lack of a better term)?

Does each circuit suck out a given amount of power (amps?) and trip when it reaches the circuit breaker value. That is if I suck 16amps my 15 amp breaker will trip?

If I have 20 or more 15 amp breakers, does this mean that I am counting on the fact that they all will not be sucking their maximum at the same time?

For example, if I have 20 15 amp circuits at maximum is that not 300 amps on my 200 amp circuit? What happens if that occurs?

I think I saw that when you install the wall connector you choose a maximum power setting. Would it make sense to install a 60 amp circuit but choose something like 32 amps in the charger? The idea being that the 60 amp breaker would be heavier duty than a 40 or 50?

The manual is 44 pages. I will definitely study that before I talk to my electrician.

 

[ERD50]

before putting in a diy home charger, be sure to look at this video! Nothing to sell, but it seemed like good advice. I never thought of it.

https://youtu.be/tDp9PhPJhUI

Interesting video, some very good content. I'll add to some of the responses so far, that covered a lot.

I'd like to see them (or someone) condense that down to a bullet-list of do's and don'ts, something more accessible for the average homeowner. Then follow up with some of the reasons.

I'm a bit surprised that it looks like you need to buy a 'special' high-quality connector. IMO, the UL rating ought to cover it. Code does call for de-rating to 80% for "continuous (more than 3 hours). Well, continuous should mean "continuous".

I get that an EV can present a load uncommon to almost anything. A/C, resistivity heat, electric water-heaters and other high current loads are going to cycle. Even a water heater starting from cold is only a few hours. So an EV does create a somewhat new situation.

Certainly attention must be paid to assure every connection is rock-solid. Any poor connection is going to generate a lot of heat at those currents. But I'm disappointed in UL or other certification places if they certify a connector, but then you are told to buy a 'better' one, for this use. "Continuous" means "continuous".

I had figured the well respected (and $$$) brands (like Hubbel) might offer longer lifetime in terms of wear, or are stronger against breakage. But a cheap connector that is certified ought to be safe for that use, or it shouldn't be certified. That's my stand on it. But in light of this - use the Hubbel!

Side note: Bakelite has an interesting history. Essentially the first plastic, developed well over 100 years ago, and yet still superior for some applications like this.

-ERD50

 

[ERD50]

....

What is a "fire rated wall"? I am planning to mount the charger to the cement outer wall in my cellar/garage. From a quick Google it seems that the cement wall qualifies. ...

I think they mean not mounted to a bare stud wall, or wood covered wall. I think 5/8" drywall qualifies as 'fire rated'. One hour protection is the standard, IIRC.

-ERD50

 

[Masquernom]

I haven't researched charging EV's yet. Not in the market right now. But, can't you just plug an EV into a standard 120 VAC outlet in the garage and let it charge over night? I know it would take several hours, but shouldn't overnight be enough?

 

[REWahoo]

But, can't you just plug an EV into a standard 120 VAC outlet in the garage and let it charge over night? I know it would take several hours, but shouldn't overnight be enough?

Using a standard 110v outlet to charge adds ~3 miles of range per hour. That may be enough for some people but most of us would like to be able to do better, which requires a 240v outlet.

 

[MRG]

I haven't researched charging EV's yet. Not in the market right now. But, can't you just plug an EV into a standard 120 VAC outlet in the garage and let it charge over night? I know it would take several hours, but shouldn't overnight be enough?

You can add about 4 miles of range per hour of charging with a 110 circuit. Depending upon how much you drive, it might be enough. We had a visitor in our neighborhood last year who kept his model 3 going with it a summer.

 

[audreyh1]

I haven't researched charging EV's yet. Not in the market right now. But, can't you just plug an EV into a standard 120 VAC outlet in the garage and let it charge over night? I know it would take several hours, but shouldn't overnight be enough?

Yes you can, and I have done so at my sister’s house. It’s very very slow however, like 4mph charging at 115V outlet versus 26mph charging at a NEMA 14-50 connection for my vehicle. So overnight you can gain some range, but not nearly fully charge. It’s OK for getting you to a supercharger maybe ha ha.

For my sister’s house out in the boonies I arrived with a fairly high state of charge (70%), and then just used the outlet to occasionally recoup losses from running errands. That worked well as a strategy. Now with new superchargers much closer to her place I probably won’t even bother.

 

[Alan]

Our home charger is linked to our energy company and when the car is plugged it will charge at 10p/kwh for 6 hours overnight or at any time the half-hourly rate is less than that. It also monitors how much we export to the grid from our solar panels and will switch from export to charging the car if the export rate is 1.4kW or higher. (If the car is already charged to its preset value then it won't redirect the excess solar. Unless we are going on a long trip I have the max charge preset to 80%)

 

[Ronstar]

First of all - I'm not an electrician - but have wired a few houses (with no problems so far)

...What is a "fire rated wall"? I am planning to mount the charger to the cement outer wall in my cellar/garage. From a quick Google it seems that the cement wall qualifies.

I would think so - A fire rated wall is just that - a drywall wall on the interior of a garage, or concrete wall that meets fire ratings

The part that lost me was when they talked about a "bolt on" circuit breaker separated from the other breakers in the box and using a "knife cutoff" switch.

It sounds like they recommend a bolt on breaker. Thought is that a normal push on breaker is more apt to come loose than a breaker that is screwed to the bus bar.

I assume a "knife cutoff" switch is what we call a service disconnect. I installed one on the outside of my house near the ac unit so anyone working on the ac can just pull the knife handle out to cut power to the unit. No need to come inside and turn the breaker off.

I don't know much about breaker panels.

I know that I have a 200 amp service coming into my panel. I think that there is some sort of a "bus" that the individual breaker circuits are connected to.

Does this mean that all the breakers feed off the one "wire" (for lack of a better term)?

Pretty much so. Your main house hot wire feeds the center bars. The neutral and ground wires feed their respective bus bars. Ground and neutral busses are generally connected to each other in main panels, but not connected in a sub-panel.

Does each circuit suck out a given amount of power (amps?) and trip when it reaches the circuit breaker value. That is if I suck 16amps my 15 amp breaker will trip?

Not sure if the limit is 1 amp over, but the breaker will trip when the amps attempted to be drawn exceed the breaker amp rating.

If I have 20 or more 15 amp breakers, does this mean that I am counting on the fact that they all will not be sucking their maximum at the same time?

For example, if I have 20 15 amp circuits at maximum is that not 300 amps on my 200 amp circuit? What happens if that occurs?

Most circuits (at least in my house) don't come close to using the breaker / wire rating of each circuit. I might be using 5-10 amps on a 15 or 20 amp circuit. And I believe that the biggest draw on a circuit is when certain things are turned on. ie my table saw, etc has a bigger draw when initially turned on than after it has been running a few seconds.


I suspect if the combined amperage being drawn from all of the circuits exceeds the panel amperage or amp rating of the main breaker, the main breaker will trip.

I think I saw that when you install the wall connector you choose a maximum power setting. Would it make sense to install a 60 amp circuit but choose something like 32 amps in the charger? The idea being that the 60 amp breaker would be heavier duty than a 40 or 50?

I would install exactly what the manual calls for, with the correct size wire for the amperage needed and the length of the run.

 

[joesxm3]

Thanks for the detailed explanation.

The manual says "an external cut off is neither needed nor recommended".

They also say to mount to a stud or plywood. They give screws so I am not sure how tap con screws would work. Maybe I can build a little square with studs screwed to concrete and drywall over it.

I hope that the Tesla Wall Connector product would be made well and not have issues like the 15-40 plug.

It can take max 4 gauge and specs 6 gauge for the lower amps. I will aim for 32 amps to be safe, but I thino you can change it over WiFi and also limit from the car.

 

[Ronstar]

Thanks for the detailed explanation.

The manual says "an external cut off is neither needed nor recommended".

They also say to mount to a stud or plywood. They give screws so I am not sure how tap con screws would work. Maybe I can build a little square with studs screwed to concrete and drywall over it.

I hope that the Tesla Wall Connector product would be made well and not have issues like the 15-40 plug.

It can take max 4 gauge and specs 6 gauge for the lower amps. I will aim for 32 amps to be safe, but I thino you can change it over WiFi and also limit from the car.

I would think that the tap con screws would be fine for your concrete wall.

 

[Midpack]

I'm a bit surprised that it looks like you need to buy a 'special' high-quality connector. IMO, the UL rating ought to cover it. Code does call for de-rating to 80% for "continuous (more than 3 hours). Well, continuous should mean "continuous".

I get that an EV can present a load uncommon to almost anything. A/C, resistivity heat, electric water-heaters and other high current loads are going to cycle. Even a water heater starting from cold is only a few hours. So an EV does create a somewhat new situation.

You would think so, but I'm probably going to use a Bryant 14-50, maybe spring for a Hubbell.

As you note, 240V EV charging is a higher load for longer than any appliance that I know of. But more than that, appliances are rarely plugged/unplugged whereas mobile connectors may be more often - that's my primary reason for choosing a better install. I'd rather err on the side of caution, right or wrong. I assume many of the recommendations, including Teslas themselves, are partly CYA. Seems foolish to draw the line in the $XX difference in receptacles, after spending $XX,XXX for the car. EV charging is new to all of us the first time, sparky stuff is not a strength for all of us, self included.

 

[REWahoo]

You would think so, but I'm probably going to use a Bryant 14-50, maybe spring for a Hubbell. ... . But more than that, appliances are rarely plugged/unplugged whereas mobile connectors may be more often - that's my primary reason for choosing a better install.

I went with a Bryant 14-50r ($50) as the price for the Hubbell has gotten ridiculous (~$200) probably due to demand. I understand Bryant it is made by Hubbell.

As to the frequency of plugging/unplugging, I've had my 240v service for five months and after the initial plug into the receptacle, I've unplugged and plugged it back in a total of two times. Since I don't do any road trips I don't take the charger with me so I have no reason to unplug it - other than to reset it if we get a power glitch, which has happened twice in the five months I've had it. If it happens again I will try to remember to reset it by turning off/on the breaker instead of using the plug.

 

[joesxm3]

It seems that the Hubble 14-50 costs about $100 and they raised the price of the mobile connector kit to $250, so that would be $350.

The wall charger is $430 last I looked.

I suppose you would still want a mobile connector to take with you.

I have both sitting here now. I almost sent the wall charger back and have an open return ticket that allows a few week return window still.

I suppose I will end up keeping both and just write the cost off to scope creep on this project.

 

[Midpack]

I know the tradeoffs, so I'm not hoping to get into any of that. Just a simple factoid, assuming the assumptions are about right?

I'd spend $950/yr on gasoline driving my Santa Fe Hybrid at current gas prices.

Electricity to charge a Model Y at home at current published utility rates (7.67 ¢/kWh Summer, 7.29 Winter + 0.61 other per kWh charges) will run about $200/yr added to the overall utility bill. The Basic Facility Charge is fixed, we pay that regardless, so I assume the difference in kWh usage is the actual cost of EV charging.

Nice savings, more than I expected.

 

[joesxm3]

You are lucky to have such cheap electricity. My rate is more like $0.25/kwh.

But I just think the Tesla is a great car even if I don't save on milage.

But my Acura only gets about 24/gal.

 

[audreyh1]

You would think so, but I'm probably going to use a Bryant 14-50, maybe spring for a Hubbell.

As you note, 240V EV charging is a higher load for longer than any appliance that I know of. But more than that, appliances are rarely plugged/unplugged whereas mobile connectors may be more often - that's my primary reason for choosing a better install. I'd rather err on the side of caution, right or wrong. I assume many of the recommendations, including Teslas themselves, are partly CYA. Seems foolish to draw the line in the $XX difference in receptacles, after spending $XX,XXX for the car. EV charging is new to all of us the first time, sparky stuff is not a strength for all of us, self included.

I leave my mobile connector plugged into the column mounted RV pedestal at home. We happen to have a hose reel mount above it that we used for the RV, and it turned out to be an excellent holder for the mobile connector cord to the car. We only unplug the mobile connector from the pedestal when we leave on a road trip.

We only plug in about once a week, so we turn off the 50 amp breaker when not plugged in.

We do intend to install the Tesla wall charger which will be on a different column in a more convenient location.

 

[audreyh1]

You are lucky to have such cheap electricity. My rate is more like $0.25/kwh.

But I just think the Tesla is a great car even if I don't save on milage.

But my Acura only gets about 24/gal.

Our tiny Jeep Liberty only got an outrageous 17mpg. It was a great toad (tow behind the motorhome) which took care of the long distances when RVing, but stand-alone it was ridiculous.

We are at $0.15 per kWh at home here, but when we renewed the contract last year that was a big jump up from $0.11.

 

[ERD50]

... current published utility rates (7.67 ¢/kWh Summer, 7.29 Winter) ...

Nice rate, are you sure that includes all delivery and tax/fees that are based on kWh? Another thing often missed - is that 3.85 m/kWh (260 watts/mile) from the wall (what you pay for) or based on Tesla's numbers of watt-hours/mile from the battery (which doesn't include other losses from the wall)? The 260 watts/mile seems lower than most numbers I've seen?

Probably not a big add on if they were left out anyhow. You'll clearly see a savings.

....

We only plug in about once a week, so we turn off the 50 amp breaker when not plugged in.
.

Is that 50A breaker that you turn off a big 'knife switch' style (on the box?). A standard in-panel breaker is not meant to be used as a switch, like this:

.

Further reading, breakers like that can be used as switches if they are "HID" rated.


-ERD50