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The "standard" car charger is usually overkill—but your electrician might not know that [32:26]

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  • Changing a 120v line over to 240 is likely also against code even if the physical cable can handle it. 120V cable is typically white/black/green, and the electrical code prohibits using the white one as a hot leg. That’s why 240V cable of the same AWG is red/black/green. The red & black legs both carry 120V.

    Code allows painting the white conductor black which is what i do. Or at least it did 10 years ago when I last checked.

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    You might not need 50 amps now. But that line is a 1 time cost and maybe you'll want to weld one day.

  • Mostly old-ish technology, which is far more interesting because they had to be more innovative.

    Dat toaster

  • #1 is a terrible idea if you ever need to hire an electrician in the future, plan on selling your house, etc. The National Electric Code prohibits using white, green, or grey wire for a hot/load connection. The 120V cable will contain a black wire for the hot connection, white for neutral, and green for ground. To properly convert it to 240V you would need a cable that consists of black & red wires for the two 120V legs.

    If your home ever suffered an electrical fire then this sort of jury rigging is precisely the sort of thing any competent insurance inspector would spot, and insurance carriers would deny coverage for since it clearly isn’t code compliant, which means a licensed electrician didn’t install it and it wasn’t properly inspected.

    The "120 volt cable", assuming you mean NM-B aka Romex, is rated for up to 600 volts if you look at it closely. It is absolutely acceptable to use that wiring for a 240V circuit, as long as you wrap colored (not green) electrical tape around the white neutral wire to indicate it's another hot.

    Yes, there are 3-conductor (plus ground) wires one can also use for switches and 240V circuits with neutral. That neutral can be used to have 120V and 240V together (your oven may use 240V coils, but the light bulb probably runs on 120). Doesn't mean you need to have it, if your 240V circuit doesn't need a neutral. My air compressor is just a motor that can run at 240, no neutral needed, and its outlet is wired up with the same kind of Romex used for a 120 right next to it (with black tape to indicate a second hot)

  • As explained in the video you can't run 50 amps ona dryer outlet. It's 42 amps max.

    I believe dryer outlets are typically 30a@240v. That’s a nice step up than a standard outlet and simple math shows 4x the power of 15a@120v

    If you have one in your garage, then you already have an outlet that can do faster charging than a standard outlet.

    Just like you technically don’t need a 50a level 2 charger, you may not have to settle for a standard outlet. I bought a heavy duty extension cable with adapters for several different outlet types.

  • As explained in the video you can't run 50 amps ona dryer outlet. It's 42 amps max.

    Can you cite a time stamp? I don't want to watch a 30 minute video.

    I'm very curious where "42 amps max" comes from, as NEMA outlets are rated for 15A, 20A, 30A, 50A, or 60A. 42A is a rather oddball number; I'd like some context for it.

    Most dryer outlets are rated for 30A, NEMA 10-30, or 14-30.

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    A small 30 amp level 2 charger can put another 10 miles of range in a 450 Wh/mi car in 40 minutes.

    A 15 amp level 1 charger can put another 10 miles of range in a 450 Wh/mi car in 2.5 hours on paper, but practically it takes longer, over 3 hours if it downrates itself to 12 amps, and almost 5 hours if it chickens out to 8 amps.

    Another 4.5 kWh of battery gets another 10 miles of range without charging.

    Having a level 2 charger at home means any time you go home for just about any reason you can always take just about any trip again right away, without an expensive vehicle with an oversized battery.

  • I think “might be overkill” would be a better title and position than “usually overkill.”

    It factually is not.

    most people would fall behind anytime they drive further than the average number of miles.

    Assume you drive it all the way to empty, then park it and plug it back in at 7PM. Leave it for 12 hours until you leave again in the morning at 7AM. A typical small EV will charge at ~5MPH on a 110V, 1.2kW connection (faster on a 20A circuit). So 5MPH x 12 hours means you already have 60 miles of range again for the next day. And I would say that's a pretty extreme scenario.

    Realistically you would never drive it to 0% and you would probably leave it parked longer than 12 hours.

    I use L1 almost exclusively, BTW.

    Probably if you have a Hummer or something you might want something a bit faster.

    What electric vehicle gets 5 miles/1.2kWh? That's only 240 Wh/mi.

  • What electric vehicle gets 5 miles/1.2kWh? That's only 240 Wh/mi.

    What electric vehicle gets 5 miles/1.2kWh?

    Most of the small ones.

  • Agreed, and that headline is needlessly inflammatory . Looking at my EV mileage , I could almost certainly get away with just plugging into a standard outlet. However the level 2 charger means that even if I screw it up, I can be mostly charged in a couple of hours. It’s been really effective at helping me get over what range anxiety I had. It’s really helped keep car usage as a somewhat impulse thing, rather than a process: I’m ready to go anywhere anytime.

    It also means I can charge multiple EVs, if I wanted to.

    If you screw up, you can usually get to a charger a few blocks away and snag 50% of your battery in 20 minutes.

    I charge entirely off of a standard 120 outlet, and it easily handles my daily and weekly travel needs, along with my partner's numerous errands and extra trips throughout the week.

  • Code allows painting the white conductor black which is what i do. Or at least it did 10 years ago when I last checked.

    This.

    That said, it's rare that only one or two outlets in a garage are tied to a breaker. Usually they're all on one circuit in older homes, in my experience.

    If you can find a circuit like this, though, it's perfectly valid. Many chargers made for 110V also have a 230V/15 or 20 amp mode. My Mother-in-law's portable charger has a 230V NEMA 2-20 adapter that comes in the bag with it.

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    In recent test of a German auto club they found out that it‘s cheaper/ more effective to charger faster. You loose a lot of energy if you load slow over hours.

    This energy is taken by the electricity of the car. So, while charging the car is on and takes some Watts. There are just a few brands that have decoupled the charger circuit from the overall electric circuit of the car.

    Can’t find the article now, but I think charging a PHEV through a standard power plug had about 20% energy lost. It was clearly visible that a charger is a good choice.

    Edit: link https://www-adac-de.translate.goog/rund-ums-fahrzeug/elektromobilitaet/laden/ladeverluste-elektroauto-studie/?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

    You‘ll loose

    • ~10-30% AC 2.3kw Standard Power Plug
    • ~ 5-10% DC 11kw Wallbox
    • Internal car electronics are crucial: Is the loading circuit de-coupled or the entire car On?
    • Temperature or pre-heating the battery before loading reduces losses at DC charging
  • Can you cite a time stamp? I don't want to watch a 30 minute video.

    I'm very curious where "42 amps max" comes from, as NEMA outlets are rated for 15A, 20A, 30A, 50A, or 60A. 42A is a rather oddball number; I'd like some context for it.

    Most dryer outlets are rated for 30A, NEMA 10-30, or 14-30.

    Not the same person and cba to get a timestamp right now, but it's the 80% rule - the electrical stuff isn't designed to deliver the rated amperage continuously for hours on end, so for car charging, you're apparently supposed to limit it to 80%. Now, 80% of 50 isn't 42 but 40, so not sure if it's a case of 80% not being a precise number or a mistake here, but it roughly checks out.

  • You explained how it's doable when you drive 60 miles

    Read it again. I said 60 miles the day after driving it to 0%. People don't "usually" need this.

    Average EV has 293 miles of range currently; even if you arrived home with 20% battery remaining and you only wanted to recharge to 80%,

    Thats 176 miles of range. People don't "usually" need that.

    At least once every few months we take a day trip to the nearest "big" city, which is 105 miles away.

    You said all of this already and I already replied to it.

    I'm certainly not saying that a L2 charger is a must for...most people. But I would not agree that L1 is enough for most people.

    🤔 Wat. Do you think there's like a L1.5 or something?

    Wat. Do you think there's like a L1.5 or something?

    There's the option of a level 1 charger at home, supplemented with an occasional stop at a fast charger.

    The L1 charger is not quite enough to keep up with their usage, but their usage isn't enough to make an L2 absolutely necessary.

  • In recent test of a German auto club they found out that it‘s cheaper/ more effective to charger faster. You loose a lot of energy if you load slow over hours.

    This energy is taken by the electricity of the car. So, while charging the car is on and takes some Watts. There are just a few brands that have decoupled the charger circuit from the overall electric circuit of the car.

    Can’t find the article now, but I think charging a PHEV through a standard power plug had about 20% energy lost. It was clearly visible that a charger is a good choice.

    Edit: link https://www-adac-de.translate.goog/rund-ums-fahrzeug/elektromobilitaet/laden/ladeverluste-elektroauto-studie/?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp

    You‘ll loose

    • ~10-30% AC 2.3kw Standard Power Plug
    • ~ 5-10% DC 11kw Wallbox
    • Internal car electronics are crucial: Is the loading circuit de-coupled or the entire car On?
    • Temperature or pre-heating the battery before loading reduces losses at DC charging

    Did that account for battery lifetime, because if not, that could offset efficiency gains as fast charging degrades batteries.

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    I watched the video and it seems to make good points, but no matter how many times I see something related to US power circuits it just feels so ... antique? I have 3x25A fuses on the house and several 3x16A outlets around so getting 11kW out is just a matter of plugging in a socket.

    Obviously it would be a good thing to have controls so that water heater, floor heating or sauna stove aren't all on together but I think I've replaced a single 25A fuse over 10 years we've lived on this house and I'm pretty sure that was caused by a small(ish) surge on the grid and not our load.

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    We have a granny charger that came with one of our EVs that we use as a backup and with our caravan to charge on sites that allow it. As I am UK it tops out at 2.4kw (10A @ 240v) and its annoyingly slow even charging for more than 12 hours at a time.

    Our main home charger is 7kw, and as we get cheap electric every night for 7p a KwH for 5 hours, we can charge about 40kwh in that time period. Means even our largest battery is fully charged in two nights from completely empty. If we tried that with the granny charger it would cost significantly more, as it would be up to 40p a KwH outside of the main hours and take 40 hours to charge the same amount.

    Now if you doing only a few miles a day, less than 40 miles (4 miles per KwH, charge for the 5 cheap hours using the cars charging timer, charge 10 KwH), it might work out ok for you, but then charging every day cannot be good for the battery? I know it would get annoying quite quickly. It would also get pretty painful if you have more than one EV, we have three between us and the kids, so its not remotely practical.

  • We have a granny charger that came with one of our EVs that we use as a backup and with our caravan to charge on sites that allow it. As I am UK it tops out at 2.4kw (10A @ 240v) and its annoyingly slow even charging for more than 12 hours at a time.

    Our main home charger is 7kw, and as we get cheap electric every night for 7p a KwH for 5 hours, we can charge about 40kwh in that time period. Means even our largest battery is fully charged in two nights from completely empty. If we tried that with the granny charger it would cost significantly more, as it would be up to 40p a KwH outside of the main hours and take 40 hours to charge the same amount.

    Now if you doing only a few miles a day, less than 40 miles (4 miles per KwH, charge for the 5 cheap hours using the cars charging timer, charge 10 KwH), it might work out ok for you, but then charging every day cannot be good for the battery? I know it would get annoying quite quickly. It would also get pretty painful if you have more than one EV, we have three between us and the kids, so its not remotely practical.

    Granny chargin', not triple phasing like you should.

  • I watched the video and it seems to make good points, but no matter how many times I see something related to US power circuits it just feels so ... antique? I have 3x25A fuses on the house and several 3x16A outlets around so getting 11kW out is just a matter of plugging in a socket.

    Obviously it would be a good thing to have controls so that water heater, floor heating or sauna stove aren't all on together but I think I've replaced a single 25A fuse over 10 years we've lived on this house and I'm pretty sure that was caused by a small(ish) surge on the grid and not our load.

    I'm not sure what you mean by this. Any modern US house would have a similar capability, it's just older homes that would struggle since there would never be a need for such high power devices in a garage.

    Most older garages would only need enough power to run a single lightbulb, if it was slightly newer, maybe a low power automatic garage door opener.

    It's the same in any country with buildings over 100 years old.

  • Granny chargin', not triple phasing like you should.

    You almost had me charging? You never had me charging - you never had your car charging, it had tripped the socket

    Pedantic but: 7kw isn't three phase in the UK, just 30A. Three phase electric can give you up to 22kw in the UK for charging, obviously not every EV can charge that fast, most only go up to 11kw AC. I would kill for that extra charging speed but I can't justify the extra cost and effort to get it fitted by the electric company

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