Using an extension cord for a level 2 charger

Discussion in 'Clarity' started by ozy, Jan 5, 2019.

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  1. ozy

    ozy Active Member

    A neighbor of mine showed me an alternative solution he had come up with to charge his Tesla. His electrical panel was far from his garage and he had received high quotes for installing a 240V panel to his garage. Instead he purchased an RV 50amp 75 ft extension cord (Nema 14-50)

    He then had an electrician hook one end of the extension cord to the panel and the other end ran along his outside wall all the way to the garage where it was connected to a charger. Apparently, this solution cost him about $750 whereas the work to install a 240V plug in the garage was over $2000. Just wondering of other people have done this as well? If I do the same can I use an adaptor on this extension cord and use the charger that came with the car? Or do I have to purchase a dedicated 220V charger to connect to this?
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  3. Texas22Step

    Texas22Step Well-Known Member

    I am no expert at any of this, but it is noteworthy that the Clarity manual (on p 454) states, "Do not use extension cords, adaptors, or multi-outlet plugs between the charging cable and the outlet." Now, it is not clear why Honda includes this warning in the manual -- it might be deference to full employment for all electricians or some worry about possible fire liability on their part, or maybe something else. But I would want to find out why Honda recommends to avoid this sort of set-up before I spent money and time to try it out myself.

    All of this said, note that the charger that comes with the Clarity is strictly 110V, and is not interchangeable with a 220V power supply as your question implies. If you are not going to use a L2 charger, maybe getting a 15A dedicated 110V circuit installed by an electrician to your preferred charging spot would be far less expensive than a 220V dedicated line. Or maybe there is an existing 15A 110V receptacle already installed on your home's exterior that you might be able to use with the OEM 110V charger?
    Last edited: Jan 5, 2019
  4. Viking79

    Viking79 Well-Known Member

    National electric code doesn't allow running cords through doors or holes in the wall. I find it funny that someone buying a Tesla wants to save a few bucks on installation.

    That being said an extension cord can work fine, but requires extra safety consideration. You have much more exposed cord to damage (proper installation would have the cord protected by conduit or in the wall). The connectors can make poor contact and overheat, as they are prone to corrosion not seen with hard wiring.

    If using an extension cord, regularly check it for heat buildup. Grab plug, and run hands along length an hour after starting charging to feel for hot spots. In case of OEM 120 V EVSE, the recommendation is for weatherproofing and for heat/safety issues with cheaply made or worn and damaged cables. Also, I assume the factory cord (not positive Honda does, but many do) has a temp sensor in the plug to detect if the outlet is getting hot. That would not work if plugged into an extension cord as the outlet is generally where the heat buildup is. It would detect if extension cord got.

    My recommendation is hardwired is safest, then plug in EVSE, then extension cord is only temporary measure and only if you are smart about it.
    David Towle and ClarityDoc like this.
  5. craze1cars

    craze1cars Well-Known Member

    To directly answer your question, no you cannot connect the 120v level 1 charger that came with the car to a 240v circuit....

    I’m not fully understanding your question I’m afraid.

    And what you describe as to what the electrician did for your neighbor in terms of permanently hooking up an extension cord to a panel, is a flagrant violation of every electric code, but absolutely it would function. I’d like to see photos of this setup...
  6. Sandroad

    Sandroad Well-Known Member

    The RV industry makes adapters for everything, including adapters for adapters. But, if you went from the 50A receptacle to the Clarity OEM charger with an adapter, you’d still only get Level 1 charging. You’ll have to get a Level 2 charger to get Level 2 charging. And, IMHO, no electrician worth his\her license would ever hardwire an extension cord (RV or not), run it unprotected along an outside wall, and call it good. That would never pass inspection.
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  8. JackH

    JackH Member

    IF the electrical panel is on the exterior of the house .....
    IF there was a 240v outlet installed at the panel .....

    Then, using a properly rated extension cord would not be a problem. It would be no different that hooking up an RV or a even a welder.
  9. DucRider

    DucRider Well-Known Member

    I seriously doubt a licensed electrician performed this install (or he/she won't hold that license for long). This is as unsafe an installation as I have ever heard of and quite clearly was not permitted or inspected. I don't know your relationship with your neighbor, but that is a house fire waiting to happen and I would let them know that:
    1) It's unsafe
    2) He got ripped off if he was charged $750 by that "electrician"

    He should call the city/county to get it inspected, then he will have plenty of basis to get his $750 back.

    And, unlike many other EVSE's (the "charger" is built into the car) that come with EV's, the one in the Clarity hasn't had any reports of being used with 240V (either successfully or unsuccessfully). Every EVSE has warnings not to use them with extension cords, but some do anyway.
    David Towle likes this.
  10. ozy

    ozy Active Member

    Just to be clear...This was not a "permanent" hooking of an extension cord. The electrician simply installed a 240V outlet 1 foot away from the electrical panel in a weatherproof box. This was all he was paid to do and he didn't really care what happened after that. There is no liability whatsoever on his part. My neighbor then went ahead and got this long extension cable that plugged into the 240V end and snaked it around the outside perimeter of his house (securing it to the wall) and into the garage. So the cord is exposed to the elements but the key components ie: the 240V plug and the other end of the cord are
    Perhaps I didn't describe this clearly enough....This was not a "permanent" hookup of an extension cord. The electrician simply installed a 240V outlet 1 foot away from the outdoors electrical panel in a weatherproofed box. This was all he was paid to do and he takes on no liability at all for what you do with that plug (he charged $250). My neighbor then went ahead and got this 75 foot extension cable that plugged into the 240V end and snaked it around the outside perimeter of his house (securing it to the wall) and into the garage. So the cord may be exposed to the elements but the key components ie: the 240V plug and the other end of it are not. Imagine if you had a large garage with a 240V plug and you wanted to charge a car that was 75 ft away from that plug. This is the same scenario except for the fact that about 50 feet of that cord is permanent outdoors.

    Followup: I had an electrician come to the house today and basically told me that it would be very expensive ie: "thousands" of dollars to run a dedicated 240V plug into my garage. Said that he would have to go through walls etc. He then gave me the option of running a hard wired cable from the outside panel box, around the house (in a trenched conduit) and into the garage. He said that would require 150 feet of copper wire, trenching, conduit etc and it would be less expensive. The third option he gave me was exactly what my neighbor did ie: install the 240V plug near the panel and leave it up to me to run whatever extension cord I wanted. He felt that technically this would not be "legal" but that it was safe. In fact, he said that in his own house he has a heavy duty extension cord running across his side yard to a little shed that he works in.
    marshall likes this.
  11. marshall

    marshall Well-Known Member

    As long as the wire gauge is large enough for the current it's carrying, the cable is UV rated, water proof, and the it's protected from physical damage, I don't see a problem. I would probably use twist type plugs and receptacles for a little bit more safety.

    I would make my own using SOOW cable.
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  13. DucRider

    DucRider Well-Known Member

    So it's not permanent, or it is?
    "Safe" is relative, and an installation like this violates the NEC because it not deemed safe. You have a permanently mounted electrical cord with no protection from physical damage (among other issues).

    The problem with "workarounds" to avoid doing an installation that complies with safety standards is that they work great - right up until the time they don't. Many years ago I did a brief stint doing insurance related inventory of burned houses and businesses. In addition to actual fire damage, people vastly underestimate the kind of damage smoke and water will do. The property loss is bad enough, but the ones where lives were lost were worse. More than a small percentage were electrical in origin. Your money, your belongings, your life, so entirely up to you. But many electrical codes are the result of seeing what people do that causes problems. Prohibiting using flexible cord as a cost saving method to avoid installing wiring to code definitely falls in that category.
  14. craze1cars

    craze1cars Well-Known Member

    This explanation makes a lot more sense. Now I understand. All legitimate options. Long extension cord will need to have occasional checks for aging if you choose that route. I think kinda silly unless you plan to sell his house soon. Invest if you’re staying. Personally I’d go with permanent install, trenchers outside and then in, and I wouldn’t just run a line for charger only...I’d upsize the wire and put a 100 amp sub panel in the garage, and then wire the charger from there. Gives you future options.

    Now you can simply make a choice on what you want to do.
  15. ozy

    ozy Active Member

    This would be a great option. However, for some reason I'm finding that the cost of doing things in the L.A area is far more than in other parts of the country. The quotes that I've been getting are so crazy that I wouldn't even consider them. If I owned a Tesla I may be more roped into the need for level 2 charging. However, with a PHEV that only needs to charge 47 miles and has no range anxiety anyway, I doubt that I'll be spending the $2500 for what you just suggested (that's about the price that they gave me). I think that my level 1 charger will be fine for most occasions. I come home at around 7pm and leave for work around 6am; therefore, the car is not 100% charged but it's close. I have seen some claims out there for level 1 chargers that are "twice as fast" as the OEM level 1 chargers; and if this is true, this may be a very convenient way of at least getting a 100% charge each morning. I'll post this question on a seperate thread.
  16. craze1cars

    craze1cars Well-Known Member

    This claim is not mathematically possible....beware of such claims. You need a 240v power source to charge any faster than a level 1 charger. There is no way around it.

    $2500 sounds fair for a sub panel, given the distance you’re describing this run to be. I can see $1000 in materials alone if 150 feet is true. I’d spend 2 solid days doing that install...trenching and whatnot. And your homes value will increase likely by the same amount. In your shoes, I’d make the investment.
    Last edited: Jan 5, 2019
  17. KentuckyKen

    KentuckyKen Well-Known Member

    Well, I must respectfully disagree. You can get a 16 Amp Level 1 EVSE that runs on 120v that many have found to fully charge in 4-5 hours which is approximately twice as fast as the OEM Level 1. You just have to have a dedicated 20 Amp circuit.
    Many have bought this one By Duosida for $200:

    However, I’ll stick to my tried and true Charge Point Level 2 32 Amp with phone app monitoring and scheduling.
    Last edited: Jan 5, 2019
  18. David Towle

    David Towle Well-Known Member

    Why is everyone so hot on spending thousands getting a 240 volt charger for a car that charges in 12 hours on the no cost 110 volt system that comes with the car?
    4sallypat likes this.
  19. That’s where I’m at, especially with gas as cheap (relatively) as it is. There seems to be precious little economic advantage to EV mode at these prices. That said, I still try to operate on electricity as much as possible. But for our particular situation, a full charge overnight generally suits our needs.

    Gas goes up substantially, and it will be time to reconsider.
  20. insightman

    insightman Well-Known Member Subscriber

    I enjoy driving on EV power the way some appreciate the smooth power of a V-12 ICE. So it's for the joy of EV driving that I always seek to maximize my ICE-less miles, despite the low gas prices and the added expense of a Level 2 EVSE. I plan the thefts of my wife's Clarity to divide my expeditions so as to allow a couple of hours between them for charging. She's starting to complain that I get to drive her Clarity more than she does, but I make sure it's always available for her (with a healthy charge in the battery) when she wants it. My 3-cylinder Insight is feeling cruder and cruder.
    4sallypat and barnesgj like this.
  21. MNSteve

    MNSteve Well-Known Member

    My motivation is more based on the way the car drives on EV than in any cost savings. And yes, carbon footprint is a concern, although <blasphemy alert> not a strong one for me. I just strongly, very strongly, perfer the quiet of driving on EV. For whatever reason, the ICE really bugs me in non-highway driving, but does not bother me when I'm on the highway.

    But even so, I can't logically justify the expense of a L2 charger. My driving pattern is to take the car out once during the day, and when it gets home, I plug it in, and the L1 charger gets it ready for the next day with no issue. When I'm on a trip, having a L2 charger at home would not help. The only real motivation I have for installing a L2 charger is pre-conditioning; I find it useless on a L1 charger but quite reasonable with L2. Now if I could actually remember to turn it on 30 minutes before I leave . . .
    insightman likes this.
  22. craze1cars

    craze1cars Well-Known Member

    Ozy doesn’t have a 20 amp dedicated circuit and he doesn’t want to pay one to run a new circuit.

    I also have a hard time mathematically seeing how a 120v 16 amp charger can charge a car in 4 to 5 hours, when the OEM one which is known to consume something like 12 amps on the OEM 120v takes 3 times longer? Something is off there...But I don’t own one, I’m just a shadetree electrician who mathestimates well...

    As for why people are spending money on fast chargers, I can only speak for myself...our Clarity leaves and returns to the house 2 to 3 or even 4 times per day, often 30 to 40 miles at a time. So to minimize fuel usage we use the level 2 charger speed charging capability a LOT. For those who just commute to work and home and that’s it? I agree they likely would see little benefit from having a fast charger. But our car just never sits in the garage for 12 hours at a as a shadetree electrician I installed my own for just cost of materials...
  23. 4sallypat

    4sallypat Active Member

    Has anyone calculated the cost to recoup the L2 charger versus using the OEM L1 charger ?

    I know that using a L2 charger is more efficient and uses less total kWh than the L1 charger but I would like to know if anyone has taken the time to compute the cost of 240V L2 per charge cycle compared to 120V L1 charge cycle ?

    That would be a way to calculate how long the ROI for the L2 charger (before rebates)....

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