Do I need a home charging station or just a 240 volt outlet? Advantages to either?

Discussion in 'General' started by jeffgamer, Oct 16, 2019.

  1. jeffgamer

    jeffgamer New Member

    Hi! Florida USA user here! In the space of one week, my wife and I have gone from the gas world to the (mostly) electric world. Bought a used 2017 Chevy Volt and a new 2019 Nissan Leaf Plus (I've never spent so much at one time since buying my home -- EEP! -- but we're psyched to be taking this step). We are having an electrician come to our home in a few days to install...something...on the outside of our house, just outside our can't-park-the-car-in-it-because-it's-too-cluttered garage, so we can easily charge up the cars.

    But what should we have him install? A 240-volt outlet? Or do we need one of these charging stations I see advertised? Are both fine options? What are the advantages of one versus the other?

    Our neighbor has a plug-in and just inserts the cable into his 240-volt outlet in his charging station. And yet we've been told by others that that's not workable...that we NEED to have a charging station for our home and not just the outlet. Obviously, that would be a more expensive endeavor. I need to call back the electrician to clarify what we want, and I would love to be more confident in KNOWING what to tell him.

    Any feedback the community has would be SO appreciated!!

    Thank you!!
  2. manybees

    manybees New Member

    You will need a separate 240 volt, Level 2 EVSE (charging station) on its own circuit whether you use an outlet or hardwire it.

    I would call your electrician and tell him/her you need a 240v circuit installed for electric vehicle charging, and then have the electrician come out to assess your situation and give you an estimate. I would get 2-3 estimates as prices can vary wildly. Prices will also depend on lots of factors and will range from a few hundred to a few thousand dollars.

    I believe the EVSEs (charging stations) provided with the Leaf and Volt are Level 1 (120v and can plug into a regular household outlet). If you want faster charging, you'll have to purchase a 240 volt, Level 2 EVSE separately (I recommend Clipper Creek as a reliable, UL-listed brand).

    A few things you'll need to consider for a Level 2 EVSE:
    • Hard-wired or plug-in? An EVSE can either be hard-wired to your electrical system or can be plugged into an outlet. The most flexible option is to install a 240 volt outlet and then plug an EVSE into that. This way, if you ever move from your house, you can just take your EVSE with you, rather than having to remove something that's hard-wired. You could also potentially bring your EVSE with you on a road trip if you know you'll be able to plug in elsewhere.
    • Dedicated circuit. Most Level 2 EVSEs require a dedicated electrical circuit, as the circuit will be drawing high-voltage current continuously over extended periods of time. This often means that an electrician will have to wire a whole new circuit rather than tapping into an existing one. If the run from your current electrical panel is far, this adds to the cost, too.
    • Amperage. The maximum amperage available to be drawn at 240 volts will depend on a number of factors, but will determine what Level 2 EVSE to buy and what type of outlet to install. What's the max amperage of your home's electrical service? How much load is already being used in your home? What's the peak load? How far from the electrical panel will the run be for the new circuit? Any competent electrician will be able to assess all of this, but you will need to purchase a Level 2 EVSE that works with the available amperage. (As a side note, you can calculate the kilowatts (kW) the EVSE will be able to send to the vehicle by multiplying volts times amps; e.g. 240v @ 30 amps will be able to provide a maximum of 7.2 kW to a vehicle, which means that, in an hour, you'll be able to add 7.2 kilowatt hours (kWh) to your vehicle if the vehicle can accept 30 amps of current—which I don't think the Volt can, by the way. In this way you can calculate how many miles can be added to a vehicle in an hour if you know how many miles per kWh your vehicle gets: simply multiply the kWh being added times the miles/kWH your vehicle gets; e.g. 4 miles/kWh X 7.2 kW per hour = around 28 miles of range being added per hour.)
  3. Francois

    Francois Active Member

    I have a 240V/30a station but the dedicated circuit for it on my electric panel is 40a, not 30a. Don't know if this is also a regulation for the USA or if this is just a Canadian thing.
    Last edited: Oct 19, 2019
  4. marshall

    marshall Active Member

    You are limited to 80 percent of the full current value, including the amperage draw of anything else on the same circuit. So in your case of a dedicated 40 amp circuit, 80% of 40amp is 32 amps.

    On a 30 amp circuit, 80% of 30 amps is 24 amps. So your 30 amp ESVE would draw too much current on a 30 amp circuit.
  5. Francois

    Francois Active Member

    Thanks for the explanation. It's easy to follow and much appreciated. :)
  6. marshall

    marshall Active Member

    Your neighbor is using a portable EVSE. Your cars should have came with a 120 volt portable EVSE.

    It depends on your circumstances as to whether or not you need a 240 circuit and a new EVSE. A retired person, a person who can charge at work, or has access to free or low cost public charging stations, may not need to a dedicated 240 volt circuit and EVSE.

    However, most folks will need a dedicated 240 volt circuit and new EVSE.
  7. bwilson4web

    bwilson4web Well-Known Member

    I would add a WiFi or other network management interface to the EVSE requirements. The advantage is you get a better idea of how this and the future cars actually work.

    Bob Wilson
  8. tps5352

    tps5352 New Member

    I am considering purchasing a Tesla next year, and was also initially perplexed about the perceived need for a charging station (as promoted by auto manufacturers and aftermarket accessory suppliers). Here are some preliminary thoughts and conclusions. I'd be glad to hear other viewpoints.

    The amount of power supplied to the car being charged at home and the rate of charging are, I believe, factors of the household electrical circuit you use. The household circuit consists of (a) the initial design of the circuit at the electrical panel (inside the circuit-breaker box where electricity enters your house), (b) the power rating of the circuit breaker you choose, (c) the gauge of house wiring used (e.g., Romex 6-3 w/ground wire), and (d) the particular outlet (e.g., NEMA 14-50) or hard-wired charging station used.

    Based on what I’ve read, to charge a car at a reasonable rate you usually want to use a 220/240-volt circuit (similar to that used for clothes dryers, electric ranges, and hot tubs). But to get an adequately fast charge, you also want reasonably high AMPERAGE (e.g., ~60 amps). (Of course, you should follow the auto manufacturer's recommendations.) If you already have an adequate circuit and accessible outlet (say in the garage) with sufficient voltage and amperage, that is great. But if not, you need to install an adequate dedicated and accessible circuit (probably using a professional electrician).


    240- and 120-volt Outlets - 2.jpg Tesla Charging Station.jpg

    The electrical power (voltage and amperage) available to charge your car is not determined by the charging station or outlet alone. It is determined by the electrical circuit (inside your walls) that the charging station or outlet is attached to.

    So assuming you have or install an adequately-powerful dedicated circuit, what is the advantage of a $500+ (Tesla, ClipperCreek, or other) charging station over a simple outlet?

    Here are possible advantages of a (hard-wired) charging station that I can think of:
    • Appearance. A charging station is neat and tidy and looks professional. But so, also, does a properly-installed outlet. A standard outlet is simpler, smaller, and usually easier to install.

    • Weather-proof and locking charging stations are available. But so, too, are weather-proof and/or locking outlet covers (which are much cheaper).

    • A charging station probably comes with a permanently-attached charging cable that cannot be easily removed (i.e., stolen). In comparison, a simple outlet requires that you already have, or need to purchase, an adequately-sized, detachable cable with appropriate plug (to attach to your 240v outlet). And new cars may come with suitable charging cables/adapters, so you may not need to buy one.

    • A charging station may have a built-in hanger to keep the cable neatly stored.

    • Since it is usually installed by a licensed electrician, presence of a charging station and an installer helps ensure that the electrical household circuit powering it is adequate and safe (i.e., meets local code and the auto-maker’s requirements).

    • Newer, more expensive charging stations may be rated for higher amperage (e.g., >60 amps), and thus charge more quickly. However, keep in mind that a charging station CAN ONLY dole out the electrical power supplied by the household circuit behind it. An adequate electrical outlet at the end of the same circuit supplies the same voltage/amperage as a charging station.

    • Newer charging stations my include WiFi capability that can, I assume, provide the car-owner with helpful charging information and convenient functions.

    • A charging station should safely charge and shut off (e.g., to prevent overcharging), have features liker timers or trickle-charging, and may contain an internal fuse or circuit-breaker. But I assume that today's cars may have those features built in. And if the household circuit is properly installed, additional circuitry safeguards may be unnecessary.
    My Initial Conclusion: As long as you use an adequately powerful and properly/safely installed household electrical circuit (which is required no matter what), an additional charging station seems superfluous to me, and therefore is probably NOT worth the (often) considerable additional expense to purchase and install, especially if your vehicle has built-in charging capabilities and safeguards. The bulk of your charging-preparation expenditures should instead be directed towards installing an adequate and safe (up to code) house circuit using a proper 240-volt outlet (e.g., that matches the plug of the cable your car comes with). This would be necessary whether you just install an outlet or go the extra mile and also buy a (costly) charging station.

    What do other people think?
  9. marshall

    marshall Active Member

    I think you need to read up on what a EVSE does.

    Note an EVSE is not a charger. A level 2 charger is built into the car. Unfortunately, folks interchange the two terms.
    TheLight75 and KiwiME like this.
  10. davidtm

    davidtm Member

    I would add that the other limiting factor is the speed of the charger built into the car. Most are limited to 6 or 7 kW, so anything over 50A on the circuit is overkill, unless you are future-proofing.
    KiwiME likes this.
  11. tps5352

    tps5352 New Member

    Good comments. Here is what I think I know, so far.

    The acronym “EVSE” stands for the rather vague and ambiguous phrase, “Electric Vehicle Supply Equipment.” In the case of a home “charging station” (admittedly a possible misnomer) or “charging dock” (ditto), it means an optional device installed at the wall-end of a dedicated electrical house circuit intended to more safely pass electricity through to the vehicle from the house circuitry via a cable attached to the car. I will continue to call them “charging stations,” even though you are correct in pointing out that the actual “charging” (i.e., conversion of household alternating current [AC] to direct current [DC] stored in a battery) takes place within the car itself.

    As we know, a home charging station can be a Level 1 (120-volt) or Level 2 (240-volt) device, presumably matching the voltage and amperage of the house circuit feeding electricity to it. I assume that most people who go to the trouble and expense of installing a home charging station desire faster charging, and hence tend to install a dedicated 240-volt circuit coupled to the matching docking device.

    According to industry websites, home EVSE (or “EVSE control”*) charging stations may include the following characteristics and abilities:
    • They are primarily intended to safeguard (a) users, (b) vehicles, and (c) the power grid by ensuring that during vehicle charging at home industry engineering and safety standards are implemented and maintained.

    • But they may admittedly include redundant safety features.

    • They can manage the correct current level during the home charging process.

    • And they “lock-out” possible current flow when the cable is not attached to the car.

    • Plus they detect hardware faults and shut current flow off if a problem is detected.

    • But they do not manage the power transfer (charging) process itself—that is normally handled by the car’s on-board mechanisms—unless there is a mechanical fault, in which case they can halt the power transfer process.

    • They can include timing functions, a convenient feature.

    • And they can eliminate the need for most user interaction and management during the home charging process.

    • Plus they may offer WiFi-capable features.

    • Up to a point (see comment by davidtm) they may allow faster recharging at home, but only if the house circuit feeding the charging station is already at adequately high voltage and amperage. As I understand it, the rate of charging is not determined by the home charging station by itself, but primarily by the household circuit backing it up (and by limitations within the car, as davidtm points out).
    In summary, so far, my preliminary conclusion remains: I see no automatic reason to spend an additional $300 to $1,000 or more (for equipment and installation) to install a “charging station” assuming that the dedicated household circuit and outlet are properly installed, fused, and weatherproofed (i.e., meet code requirements). That said, home charging stations appear to provide additional, albeit sometimes redundant and arguably unnecessary, features. So there is certainly no harm in properly installing a name-brand, good-quality device, except for the added expense, which can be considerable. If one is available at a discount or as a bonus, or perhaps you have a household with more than one kind of electric vehicle, then by all means…

    Also, in my previous post I did not cover possible advantages of portable "charging stations" that plug into standard (e.g., 240-volt) outlets and can be used (with the proper plug adapters) on trips away from home. These devices may offer the same safety features as their hard-wired counterparts and could be advantageous on the road where the integrity and quality of a (non-commercial) charging spot is unknown.
    * What would be a more suitable name and acronym? “Charge Monitoring Station?” “Charge Safety Dock?” “Electric Vehicle Charge Monitor?” Etcetera,…
  12. tps5352

    tps5352 New Member

    Interesting. Yes, the technology is and will be changing so fast that it will be tough to keep up. For example, the online specifications on the latest Tesla home wall connector describe it as an up-to-80-amp device. I therefore assume that new Teslas either can or eventually will be able to (future-proofing) charge at that higher amperage. A household circuit created for that amperage would require 3-gauge Romex-type wire (which is unusually thick and heavy) and a suitable (Tesla recommends a 100-amp single-phase!) circuit breaker. This would surely require professional installation, and may not even be possible at some homes. As electric vehicles become more common, home electrical design and codes are going to have to adapt.
  13. bwilson4web

    bwilson4web Well-Known Member

    The early Model S had a option for 80A charging. Since then, even the Teslas are in the 32-40A range. For example, a mid-range Model 3 can do 40A but my SR+ Model 3 only goes to 31A on AC. On DC, it goes to 100 kW, over 200A DC.

    Bob Wilson
    Re-Volted likes this.
  14. davidtm

    davidtm Member

    Watched this today and learned a lot. For example, there is no "Level 3".

    Sent from my Pixel 3a using Tapatalk

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