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

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  • Not talking about the circuits, but the main electrical connection to the grid. To me it often seems like there's reluctance in overcommitting overprovisioning that capacity: as an example, four 16A circuits on a 25A main breaker. Here that's quite common, but even in Tech connections videos I've seen him bring up smart electric cabinets or automatic load monitoring when putting enough capacity on the mains to possibly go over.

    What I'm asking is, why bother? If you trip the mains by having too much load, just reset the breaker and be done with it. No need to automate things to not run into that situation, one will learn to not have the oven on while charging the car full blast. No need to gimp the charger amperage since you're running a new circuit anyway, and it's not like it's much different running a 20A circuit vs a 40A one. If that's 70% of your total available capacity, it doesn't matter – worst you have to do is walk downstairs and flip a switch.

    I don’t think overprovisioning is a thing that is realistically is a problem in the U.S. or in Germany. I know that modern homes tend to have 300amp mains. Older homes 100amps. You would have to have a house that was wired in 1920 in order to have a 20amp mains available. In that case you have bigger issues safety wise.

  • The infinitely easier solution is to let the car charger know how much power is available to draw.

    Well, true. Fair enough

  • Uh.

    I drove semi trucks in the US for years....

    You'd better either double clutch or float those gears, because if you don't, you're destroying your clutch brake, which means you'll have trouble getting it into gear from a dead stop. That applies for both upshifts and downshifts.

    Ever sit next to an old truck or bus and hear them grinding gears to get into gear?

    That's due to the clutch brake failing to stop the flywheel.

    All semi trucks in the US use synchro-less manual transmissions.

    When shifting a syncro-less transmission, YOU are the synchro.

    The clutch in these trucks has 2 positions. You either just barely engage the clutch enough to break contact, or you depress it fully to engage the clutch brake and (attempt to) stop the flywheel from spinning.

    If you do the second one while shifting a moving vehicle, you're causing undue wear and tear on the aforementioned clutch brake.

    Sure. But in the first Fast and Furious movie they're not driving syncro-less transmission semis. They're driving tricked out sports cars in a straight line and somehow having about 14 gear changes in a 6 speed manual.

  • 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

    Yes, he responds to that in the video.

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

    In here 100+ year old houses are pretty common but practically all of them still have at least somewhat up to date electrics with that 3-phase input. It's been around for decades after all. My house is built originally 1928 and my mothers house is from 1909 and both of them have 3x25A main breakers with those 380V 16A CEE sockets around.

    And as garages commonly double as a work space with 3-phase induction motors on the tools it's still pretty common to have that 3x16A available as it's not that much more expensive to pull 5x2.5mm² cable to the garage compared to 3x2.5mm² for single phase 16A outlet.

    Also, it's typically not that expensive to upgrade your panel, if you live in a zoned area. Buildings in the unzoned area typically have good electrical connections since in the countryside you typically want access to three phases.

    As an example for moving from older single phase service to 3x25A, it costs around 810 € typically, with 2000-3000 € as a worst case scenario. That's in Lahti, Finland – in Espoo it seems to be around 500 €

    Of course there's then the need to upgrade the panel as well, but that's a relatively simple operation.

    My childhood home had 3x90A breakers since it originally had a resistive heat setup, in a relatively large building (plus some other energy intensive equipment housed there). In reality it was far too much even then, the max load we calculated under full load was more like 25-30 kW.

  • Sure. But in the first Fast and Furious movie they're not driving syncro-less transmission semis. They're driving tricked out sports cars in a straight line and somehow having about 14 gear changes in a 6 speed manual.

    While true, there are syncro-less racing transmissions as well for a number of the more popular moddable cars.

  • The way that it works in most countries is that the breakers are per circuit in your wall. The breakers trip in order to prevent that single circuit from overheating and starting a fire in your walls.

    Let’s say you have a wire that’s rated for 16amps. More than that and it becomes a fire risk just threw overheating. @230v that gives you 3680w per circuit.

    If you have your industrial microwave, water heater, and car charger all going at the same time on that same circuit. This will draw way more than 3680w and thus would go over that 16a limit.

    The breakers trips once you go over that 16a limit for safety. It’s a good thing. This all being said no sane electrician would put those three things on the same circuit. lol.

    Circuit breakers are actually what enable you to safely over provision. Without them fires would just be a matter of time.

    I know it works this way in the U.S. and Germany at least.

    Also worth noting that breaker ratings are for instantaneous usage. A 15A 120v breaker can only actually support 12A of continuous usage. But it says 15, because most things use a little extra power when they first turn on. AC system spinning up the fans and compressor, for instance. Spinning things up takes more power than keeping it moving. If you put a 15A device on a 15A breaker, it would likely trip as soon as that device turned on. In that instance, you’d likely use a 20A breaker to support the 15A device instead. But that 20A breaker would also call for upgraded wiring and outlets which could support 20A.

  • Do you think a device with regulation circuits is more likely to be overloaded and start fires...?

    My guess would be yes, somewhat, probably. but maybe not much.
    As he says in the last part of the video: If it gets hot, you have a problem.

    Better ask an electrician.

    The devices sold as "EV wall chargers" are not really chargers.
    They're simple power suppliy units, whether or not it has bells and whistles to time the charging and what not.

    The actual battery charger is in the car. It will attempt to suck as much energy from the PSU as it can and it will itself balance the load and all that. Having a separate unit also trying to regulate the load seems like something that will inevitably create more heat than necessary somewhere in that chain.

    Generally speaking you do not need to protect the car from unstable supply. It will protect itself.

    I will still recommend getting a proper "EV charger" to ensure that it can utilize all the phases unlike a regular garage plug. Also to ensure that it is properly grounded, which can be an issue for some cars.

    At least here in Europe, where we have 3 phases. It's much better to have all 3 phases wide open and let the car suck a little on each, instead of having it overloading a single phase through a granny plug.

    I know the American 2 phase circuit is different, but I still believe it's better not to put any more heat inducing obstructions in the chain.

  • Uh.

    I drove semi trucks in the US for years....

    You'd better either double clutch or float those gears, because if you don't, you're destroying your clutch brake, which means you'll have trouble getting it into gear from a dead stop. That applies for both upshifts and downshifts.

    Ever sit next to an old truck or bus and hear them grinding gears to get into gear?

    That's due to the clutch brake failing to stop the flywheel.

    All semi trucks in the US use synchro-less manual transmissions.

    When shifting a syncro-less transmission, YOU are the synchro.

    The clutch in these trucks has 2 positions. You either just barely engage the clutch enough to break contact, or you depress it fully to engage the clutch brake and (attempt to) stop the flywheel from spinning.

    If you do the second one while shifting a moving vehicle, you're causing undue wear and tear on the aforementioned clutch brake.

    I can't speak for big rigs, but I drive and ride multiple manuals. Synchro or not, there's no reason to double clutch an upshift in the cars under normal or high performance situations. It'd only make sense if I took too long to shift and had the engine rpm fall far below what matches the speed of the next gear. It's a drag race. They're burning synchros to drop 6krpm to 4k in the next gear in half a second. Even in normal driving, dropping 1000rpm or more is plenty of time to catch the next gear. 2 of my mini trucks have burnt synchros on one gear each (prior to my ownership), so I'm pretty well aware of how to time it for a smoother shift on the downfall. If double clutching was necessary on upshifts, I wouldn't be able to do gasless clutchless shifting. But I can

    Downshifts, absolutely. There's plenty of reason to double clutch a downshift. The engine is, by definition, under spun for the next gear so yes, blipping it up will make it easier to drop a gear. Not needed for 1 gear at a time with good synchros, but certainly adds consistency when I do a 5>3 downshift to pass in the truck with a burnt 3rd. Almost required when I had braking problems and needed to downshift into 1st since the speed differential was far greater.

    The source of the line form the movie is probably from the theatrical soundtrack from Bullitt. The engine sound was recorded separately from a GT40. The driver double clutched because it sounded mean.

    Let's not forget the line comes from a scene in which granny shifting burnt the piston rings, dangered the manifold, made the floorboard fall off, and spilled a jar of o-rings.

    I assume you used the wrong word towards the end. The flywheel is bolted to the crankshaft. If anything stops the flywheel, the engine is now turned off.

  • Well I did say I was being pedantic, which is absolutely the best way to watch fast and furious with friends

    Friends? Sib, you watch FnF with family

    Donut Media has excellent videos about the worst and best lines. Some are dual category because they're so bad they're ironically integral to the community now

  • My guess would be yes, somewhat, probably. but maybe not much.
    As he says in the last part of the video: If it gets hot, you have a problem.

    Better ask an electrician.

    The devices sold as "EV wall chargers" are not really chargers.
    They're simple power suppliy units, whether or not it has bells and whistles to time the charging and what not.

    The actual battery charger is in the car. It will attempt to suck as much energy from the PSU as it can and it will itself balance the load and all that. Having a separate unit also trying to regulate the load seems like something that will inevitably create more heat than necessary somewhere in that chain.

    Generally speaking you do not need to protect the car from unstable supply. It will protect itself.

    I will still recommend getting a proper "EV charger" to ensure that it can utilize all the phases unlike a regular garage plug. Also to ensure that it is properly grounded, which can be an issue for some cars.

    At least here in Europe, where we have 3 phases. It's much better to have all 3 phases wide open and let the car suck a little on each, instead of having it overloading a single phase through a granny plug.

    I know the American 2 phase circuit is different, but I still believe it's better not to put any more heat inducing obstructions in the chain.

    I wish we had 3 phase, but the fact is many European homes only have 1 phase. The distribution is 3-phase, but the residential wiring is only set up to use only 1 phase and upgrading the whole electrical system of our home is simply too expensive. This is in Norway, but it's similar in many countries.

    We recently installed a charger, and the electrician put in a 32A breaker. He told us you should never run continuous draw above 80% of the breaker, which gives us 25A * 230V = 5.75 kW as our max charging speed. Not fantastic by any means, but means we can go from 10 to 80% overnight, which is good enough for us. If we need a fast charge, the local gas station has a 250 kW charger anyways, so we could top of if need be - though we have never needed that so far.

  • I can't speak for big rigs, but I drive and ride multiple manuals. Synchro or not, there's no reason to double clutch an upshift in the cars under normal or high performance situations. It'd only make sense if I took too long to shift and had the engine rpm fall far below what matches the speed of the next gear. It's a drag race. They're burning synchros to drop 6krpm to 4k in the next gear in half a second. Even in normal driving, dropping 1000rpm or more is plenty of time to catch the next gear. 2 of my mini trucks have burnt synchros on one gear each (prior to my ownership), so I'm pretty well aware of how to time it for a smoother shift on the downfall. If double clutching was necessary on upshifts, I wouldn't be able to do gasless clutchless shifting. But I can

    Downshifts, absolutely. There's plenty of reason to double clutch a downshift. The engine is, by definition, under spun for the next gear so yes, blipping it up will make it easier to drop a gear. Not needed for 1 gear at a time with good synchros, but certainly adds consistency when I do a 5>3 downshift to pass in the truck with a burnt 3rd. Almost required when I had braking problems and needed to downshift into 1st since the speed differential was far greater.

    The source of the line form the movie is probably from the theatrical soundtrack from Bullitt. The engine sound was recorded separately from a GT40. The driver double clutched because it sounded mean.

    Let's not forget the line comes from a scene in which granny shifting burnt the piston rings, dangered the manifold, made the floorboard fall off, and spilled a jar of o-rings.

    I assume you used the wrong word towards the end. The flywheel is bolted to the crankshaft. If anything stops the flywheel, the engine is now turned off.

    Yeah, meant the input shaft

  • One thing I really don't get in the discussion around EVs and charging is, why are people so afraid of tripping the main breaker? If you have a total of e.g. 17 kW available and happen to go over, just reset the main breaker (or replace it in case it's still a traditional one). It's there precisely so that you wouldn't need to care about overloading the connection.

    In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US) while using the available power to

    • heat/cool a single family home (in -20 °C weather mind you)
    • run all appliances (including the oven, stove, dryer etc.)
    • heat up a sauna
    • charge an EV
    • whatever else you typically would want to plug in, kettles and such

    While it's true you can trip the main breaker if you have everything on at the same time, typically it never happens even if there are no lockouts in place preventing overuse. And it's not like tripping it causes any permanent harm.

    Why is an electrical service upgrade constantly brought up as a solution when any home with >15 kW of available power won't need it? Is it against code to purposefully overcommit your mains in the US or something?

    Edit: there were valid concerns raised over how long-lived the breakers are (probably won't be rated for tens of fault-condition related trips), also that these smaller service specs aren't as common as I've gathered from the media. That might have something to do with this at least. Thanks for the replies – it's been an interesting discussion.

    In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US)

    Wow, how do you do that?

    Of course over-provisioning is a thing but that’s crazy. Maybe you have much smaller appliances or assume much lower usage, but 70a basically assumes 2 major appliances at a time, using close to max load, and with nothing else turned on.

    Typical 240v major appliances

    • level 2 EV charger: 50a
    • stove: 50a
    • central ac: 40a
    • dryer: 40a
    • heat pump: 50a+
    • water heater: 50a

    Of course you won’t use them all at once and they won’t usually be drawing their full rated load but I would not want to deal with being limited to one at a time so I can also turn on the lights or use the microwave

    That can theoretically draw 280a, before you even count things like lights and small appliances. If you added up all possible circuits, you may be hitting 1000a theoretical in a modern house. I’m comfortable that My 200a service will handle any combination I might use, but 70a definitely not

    By contrast I once lived in an apartment with 60a service. It did not have most of these large appliances but I frequently tripped the main with combinations like stove + window ac + microwave + lights

  • One thing I really don't get in the discussion around EVs and charging is, why are people so afraid of tripping the main breaker? If you have a total of e.g. 17 kW available and happen to go over, just reset the main breaker (or replace it in case it's still a traditional one). It's there precisely so that you wouldn't need to care about overloading the connection.

    In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US) while using the available power to

    • heat/cool a single family home (in -20 °C weather mind you)
    • run all appliances (including the oven, stove, dryer etc.)
    • heat up a sauna
    • charge an EV
    • whatever else you typically would want to plug in, kettles and such

    While it's true you can trip the main breaker if you have everything on at the same time, typically it never happens even if there are no lockouts in place preventing overuse. And it's not like tripping it causes any permanent harm.

    Why is an electrical service upgrade constantly brought up as a solution when any home with >15 kW of available power won't need it? Is it against code to purposefully overcommit your mains in the US or something?

    Edit: there were valid concerns raised over how long-lived the breakers are (probably won't be rated for tens of fault-condition related trips), also that these smaller service specs aren't as common as I've gathered from the media. That might have something to do with this at least. Thanks for the replies – it's been an interesting discussion.

    why are people so afraid of tripping the main breaker?

    Not everyone know as much as electricity as you, I think is natural to be afraid of something you not know so much and that potentially can burn your house.

  • In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US)

    Wow, how do you do that?

    Of course over-provisioning is a thing but that’s crazy. Maybe you have much smaller appliances or assume much lower usage, but 70a basically assumes 2 major appliances at a time, using close to max load, and with nothing else turned on.

    Typical 240v major appliances

    • level 2 EV charger: 50a
    • stove: 50a
    • central ac: 40a
    • dryer: 40a
    • heat pump: 50a+
    • water heater: 50a

    Of course you won’t use them all at once and they won’t usually be drawing their full rated load but I would not want to deal with being limited to one at a time so I can also turn on the lights or use the microwave

    That can theoretically draw 280a, before you even count things like lights and small appliances. If you added up all possible circuits, you may be hitting 1000a theoretical in a modern house. I’m comfortable that My 200a service will handle any combination I might use, but 70a definitely not

    By contrast I once lived in an apartment with 60a service. It did not have most of these large appliances but I frequently tripped the main with combinations like stove + window ac + microwave + lights

    Aside from the heat pump we have all of these things and they’re often running all at once. Never had an outside

  • One thing I really don't get in the discussion around EVs and charging is, why are people so afraid of tripping the main breaker? If you have a total of e.g. 17 kW available and happen to go over, just reset the main breaker (or replace it in case it's still a traditional one). It's there precisely so that you wouldn't need to care about overloading the connection.

    In my experience people get by with a 3x25A (17 kW available, matches approximately a 70A service in the US) while using the available power to

    • heat/cool a single family home (in -20 °C weather mind you)
    • run all appliances (including the oven, stove, dryer etc.)
    • heat up a sauna
    • charge an EV
    • whatever else you typically would want to plug in, kettles and such

    While it's true you can trip the main breaker if you have everything on at the same time, typically it never happens even if there are no lockouts in place preventing overuse. And it's not like tripping it causes any permanent harm.

    Why is an electrical service upgrade constantly brought up as a solution when any home with >15 kW of available power won't need it? Is it against code to purposefully overcommit your mains in the US or something?

    Edit: there were valid concerns raised over how long-lived the breakers are (probably won't be rated for tens of fault-condition related trips), also that these smaller service specs aren't as common as I've gathered from the media. That might have something to do with this at least. Thanks for the replies – it's been an interesting discussion.

    Where I live, there is a pole fuse, which is, as the name implies, on the pole, and only a linesman can change it.

    Massive pain in the ass if that pops.

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

    I‘m not sure if fast charging degrades batteries. Just read somewhere an article stating that fast charging initially - first charge - boosts the overall capacity of the batterie due to chemical reactions that do not occur that long at anodes.

    The issue with fast charging was the thermal management - it’s getting to hot. This is managed by good battery management and a different packaging of cells nowadays. I think fast charging isn’t an issue anymore. Can’t provide you a link or such, it’s what I gathered through serveral podcasts.

  • I‘m not sure if fast charging degrades batteries. Just read somewhere an article stating that fast charging initially - first charge - boosts the overall capacity of the batterie due to chemical reactions that do not occur that long at anodes.

    The issue with fast charging was the thermal management - it’s getting to hot. This is managed by good battery management and a different packaging of cells nowadays. I think fast charging isn’t an issue anymore. Can’t provide you a link or such, it’s what I gathered through serveral podcasts.

    If you could find any evidence to support all that, i might consider it, until then, ill roll with what i know.

  • If you could find any evidence to support all that, i might consider it, until then, ill roll with what i know.

    Can you source your statement that fast charging reduces lifetime?

  • Can you source that?

    Here is a paper on the relationship between heat and battery degradation

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