WARNING: Extension Cords

Discussion in 'Prime Plug-in Charging' started by Rob43, Oct 15, 2019.

  1. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    Lately I've seen lots of talk about purchasing & using extension cords. So I wanted to go over a few things that I believe are Very Important when choosing an extension cord for your Prius Prime at 120 or 240v charging.

    Most of you that read my Rob43 240 volt 2 1/2 hour adapter charging threads/posts know my stance on Over Building these adapters with stout high quality parts & bigger 10 AWG Pure Copper wire.

    So here it is: When you go to online retailers like Amazon, I want you to do a quick search on any extension cord you're planning to purchase. Scroll down the page & locate the "HAVE A QUESTION", then where it says "Type Your Question Or Keyword" I want you to enter:

    1) "Aluminum"
    2) "Copper Clad"
    3) "Clad"
    4) "CCA" (copper clad aluminum)

    If you get ANY results from any reviewers that indicate the extension cord you're considering to purchase has these materials, DON'T BUY IT.

    Many people buy 12 AWG extension cord, but if the extension cord you purchase is Copper Clad Aluminum (CCA) it simply won't function the way you thought it would. Roughly speaking, a 12 AWG CCA extension cord has about the same resistance as a 14 AWG copper wire extension cord. Also, always use the shortest cord for the job.

    Extension cord "Resistance" = HEAT, heat is your enemy.

    Here is my favorite Voltage Drop Calculator:
    Voltage Drop Calculator

    Extension Cord Length, A good rule of thumb when buying a pure copper extension cord:
    1) 50 feet of 12 AWG should be your Maximum Length.
    2) 100 feet of 10 AWG should be your Maximum Length.

    The "Golden Rule" of acceptable percentage of voltage loss is up to 3%, LESS IS BETTER.
    Example Of A Voltage Loss Picture Below.

    Notice that when you use 100 feet of 12 AWG pure copper extension cord with a Prime 12 Amp EVSE unit at 120 volts, the voltage drop JUMPS to 3.18%, this now falls outside the margin of safety.


    Food for thought,
    Rob43

    Screenshot_2019-10-15_at_5.15.27_PM_-_Edited.png

    Screenshot_2019-10-15_at_5.31.01_PM_-_Edited.png

    Wireendssmall_-_Edited.jpg
     
    #1 Rob43, Oct 15, 2019
    Last edited: Oct 16, 2019
  2. Salamander_King

    Salamander_King Senior Member

    Joined:
    Nov 8, 2015
    4,954
    3,740
    0
    Location:
    New England
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    And if there is no mention of material used in the cable, CCA or otherwise, how can you find out?
     
  3. m8547

    m8547 Active Member

    Joined:
    Aug 8, 2018
    561
    328
    0
    Location:
    Colorado
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus

    In general, maybe just don't buy products from Amazon when quality and safety are important. It's become overrun with foreign sellers making fake "brands" to sell their low quality products. And even for products from legitimate brands, counterfeiting is rampant on Amazon, and as far as I know they still don't do much to prevent it. Finally the widespread gaming of reviews makes it hard to determine what is actually a good quality product.

    Here's a specific example of how you might end up with a counterfeit product from Amazon. An unscrupulous seller could send their counterfeit version of a product into the Fulfilled by Amazon program. As long as it looks vaguely like the real product and is labeled correctly, it will probably go into the same bin as all the other inventory of that product. Then, when you go to buy it, even if you buy an item that's "sold by and shipped from Amazon.com", you will get a product randomly pulled from the bin which might be the real thing or might be a counterfeit item that was sent in.

    Fake reviews are a huge problem with these fake brands. Even if a review has the verified purchase tag, it can't be trusted since that can be faked. The seller (or someone working on their behalf) can create fake amazon accounts that buy their product. The fake accounts pay real money, but the seller doesn't need to ship the product, and the seller can refund whoever paid the fake accounts outside of Amazon. Then the fake account can leave a good review, and it will show up as a verified purchase. The only cost to the seller is Amazon's transaction fees (and whatever the review faking service charges for farming fake accounts), which is a small price to pay for a "verified" five star review. Notice how many reviews after a page of "top" reviews are just one sentence, maybe even complete with typos or grammatical errors.

    Another way to game the review system is to pay off people who give a bad review. I left a bad review on one of these "fake brand" products once. I knew I was buying a product that was clearly a knockoff of a brand name product, but I thought it was worth a chance because it had 2000+ positive reviews. Of course when I got it, it didn't work as well as the brand name item. I left a negative review, and I got a phone call (!) from someone a few hours later offering me a $10 credit on my account plus a full refund and offered to send a replacement product if I wanted to try it again. They asked (but didn't require) me to change my review, but I feel like most people would change their review under these circumstances. Paying off people who leave lower reviews is a small cost when a few hundred or thousand good reviews could sell tens of thousands of items. Maybe that's just great customer service, but if you are using reviews to judge the quality of a product you can't really compare when one company is doing this and another isn't.

    For things like extension cords I try to stick to buying from physical stores that carry products from brands that have a real business presence in the US (or online versions of those stores). If in doubt you can also check for UL certification and look up the product in the UL database. UL takes fake certifications extremely seriously, although it might take them a while to find out if someone starts importing products with fake certification on a small scale.

    Lowe's has a good 12 gauge 15 foot extension cord. It's not the cheapest (around $35 I think), but it works well. And for 50+ feet it's easy to find 12 gauge cords in any hardware store.

    Monoprice.com carries 15A rated, UL listed 14AWG cords in 6 and 10 foot lengths, which is great if you need just a tiny bit more length. But I'd personally chose the 15 foot 12 AWG cord over a 10 foot 14 AWG cord.
     
    bisco and Rob43 like this.
  4. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    11,914
    6,132
    0
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    I have several Safety issues with Extension cords, several can be minimized by working with Rob43 so he does not give you his standard product.

    1) Every outlet/plug combo is a weak point, a dangerous point, and a potential for fire. Toyota strongly discourages extension cords since they ‘know’ that someone will manage to set fire to their house/car/family members and blame Toyota. Almost all 120 volt extension cords are rated for 15 amps at best. Even if the wires are thick, the plug and outlet are rated at 15 Amps. (Rob43 buys outlets rated at 20 Amps, but he cares) As such, the outlet/plug is where fires are most likely to start. If you bought a 12/3 or better (10/3 is better) cord the fire is unlikely to start in the middle unless you cut it. So one 50 foot cord is much safer than two 25 foot cords!

    2) Rob43 puts a Warning label or two on the NEMA 5-20R end of his cable warning you this is NOT 120 volts, like it looks. If you add a 50 foot extension cord, the warning is 50 feet away and unread. If you must use an extension cord, MUCH better to use a 240 volt cord, so the only point that looks like 120 volts, has the warning label. But this still adds extra outlet/plug pairs, but rated at higher Amperage. So it is several ways safer than using a 120 volt extension cord.

    3) (I have not asked Rob43 about this but let’s pretend he really cares about not burning down your house/car/ family members) The best cable Rob43 could make you was one the length of the extension cord you were going to buy. This way you skip one Outlet/plug pair, the only plug needing a warning label is labeled by Rob43 and he uses copper based cable, not Aluminum. Obviously Rob43 would charge more for a 37.5 foot (or whatever YOU need) than for his standard 3 foot adapter, but it would be money well spent on safety.

    4) If money is no object, or you need the advanced features, a hard wired EVSE is even safer, no outlets or plugs until you are at the car itself.
     
    #4 JimboPalmer, Oct 15, 2019
    Last edited: Oct 15, 2019
    java007md and Rob43 like this.
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    84,669
    37,243
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it isn't that big a deal to find a proper extension cord, just don't cheap out on your safety
     
  6. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    Great question, it certainly makes this tough because you really can't see inside your new extension cord.

    When I choose an extension cord, I absolutely look for some sort of packaging label that says something like: "100% Copper", or "Pure Copper Wire/Cord". Could they still cheat, yes, but I've never experienced CCA wire in a package that was clearly marked as "100% Pure Copper".



    Rob43
     
    Salamander_King likes this.
  7. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    As JimboPalmer points out, yes I could easily build anyone a much longer custom length of 10 AWG pure copper extension cord for their particular needs.

    BUT, I would really like to keep things centered on everyone knowing the risks (if any) of using an extension cord. So please do a bit of due diligence on your part BEFORE you place that order, a quality 10 or 12 AWG pure copper extension cord will serve you well for years and years provided you use it within its limitations.



    Rob43
     
    #7 Rob43, Oct 15, 2019
    Last edited: Oct 16, 2019
    java007md, Montgomery and utsug like this.
  8. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    Though I already posted these pictures somewhere else, they really belong here.

    For those of you that use any type of extension cord, Please Look at ALL of your connection points. As JimboPalmer points out, it's the connection points that are most vulnerable to electrical conductivity issues.

    Clean your connection points as needed, these pics say it all.


    Rob43

    thumbnail_(1)_-_Edited - Edited.jpg

    thumbnail_(16)_-_Edited - Edited.jpg
     
    java007md likes this.
  9. DavidA

    DavidA Prius owner since July 2009

    Joined:
    Jul 14, 2009
    2,143
    1,605
    18
    Location:
    Chicago western burbs
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I'm guessing that this power drop also happens with a remote run that any electrician installs? Let's say there is a detached garage 100 feet away from the main house and panel, and a 50A 240v is necessary for an L2 installation there. Unless copper and a significant gauge is used, are we talking about the same less formula?
     
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    84,669
    37,243
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    is aluminum legal in any state?
     
  11. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced

    Yes, you would always see some sort of loss with your above question.

    Using your provided info, I calculate a 1.65% Loss with a run of 6 AWG copper wire & a 1.04% Loss with a run of 4 AWG copper wire.



    Rob43
     
  12. noonm

    noonm Active Member

    Joined:
    Feb 5, 2019
    486
    450
    0
    Location:
    NJ
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    I do know its used heavily in overhead power lines, so its at least legal for that use.

    I also don't see why it wouldn't be legal for other uses. My understanding is that aluminum wiring is fine as long as its installed and handled properly. However, most people don't because they are used to copper wiring.

    However, for extension cords it does seem like you should go with a thicker gauge for a CCA one than you would choose for a pure copper cord.
     
  13. JimboPalmer

    JimboPalmer Tsar of all the Rushers

    Joined:
    Apr 14, 2009
    11,914
    6,132
    0
    Location:
    Greenwood MS USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Call me wildly optimistic, but I expect an electrician to use cable sized for the load expected. Sadly we can not expect car owners to use the right extension cord. We can preach "Use thick copper wire and heavy duty plugs." all day but if 14/2 is 87 cents cheaper, they will burn down their house to save that 87 cents.

    I support and encourage Rob43's attempts, but I don't hold out hope we won't have extension cord fires.
     
    Rob43 likes this.
  14. The Big Sleaze

    The Big Sleaze Junior Member

    Joined:
    Nov 28, 2019
    53
    15
    0
    Location:
    'frisco
    Vehicle:
    2020 Prius
    Model:
    Two Eco
    Bayco KW-130 Cord Storage Reel with Center Spin Handle, 150-Feet - Walmart.com

    This is one of my all time fave products. Should be on the self for under $8. Also works great for ropes, hoses and even chains. Buy 2. Keeps long cords from getting all twisted. Twist when rolling out or up is what kills cords, not when they are in use at close to or even over their max rating. Also keeps your hands clean, and tends to keep cords much cleaner since you can gently just lay them down, VS lots of dragging and unrolling all over the ground.

    IMO the big danger is not the cord, but where the cord plugs into. I've spend decades in construction and other adventures where cords are frequently taxed far beyond ratings, and worst thing that happens is breaker keeps tripping. However, that was always plugging INTO a fairly new and professionally installed system. I'd be much more wary pulling into an old knob and tube wired house that was rigged decades ago and probably has something building nests inside the wall.

    BTW, how many amps does charging a Prime pull, maxed out? Some big construction firms are now requiring 20amp cords, of which about 100ft will fit on spool in link. I recommend the cords with the little lights in the end plug to let you know you are "live" and plugged in at the other end.
     
    Rob43 likes this.
  15. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    The standard answer is 12 amps, the real answer is ~11.7 amps.


    Rob43
     
  16. The Big Sleaze

    The Big Sleaze Junior Member

    Joined:
    Nov 28, 2019
    53
    15
    0
    Location:
    'frisco
    Vehicle:
    2020 Prius
    Model:
    Two Eco
    So, "on paper", I can fully charge at max rate with a cheap-O $25 100ft 15amp? What is the least amount of amps I can use to charge with standard household 110V?

    Suppose for some reason all I have is 7Amp gen like this? Would it work? Would it cause pain to little generator? Anything not too fancy to tell the Gen "just give me about 4 amps, no hurry, don't hurt yourself"?
     
  17. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    A Prius Prime can charge at ~12 amps OR ~8 amps, your choice.

    I personally tell people to use the best quality extension cords, typically 10 AWG pure copper.

    I do not Ever recommend using a generator like that because it puts out Very Dirty Power, most likely it's modified sinewave and the harmonics are high. I've personally never experimented by using a modified sinewave source on our Toyota OE EVSE unit, but I'd guess it would either get hot-ish or simply go into fault mode.


    Rob43
     
  18. m8547

    m8547 Active Member

    Joined:
    Aug 8, 2018
    561
    328
    0
    Location:
    Colorado
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Plus
    The lowest you can set is 8A, unless you find an EVSE that can set a lower limit.

    The YouTube channel TFL had a hard time getting a Tesla to charge from a generator. The grounding is not quite right.

    Luckily the Prime has an extremely efficient, quiet, and powerful generator built in! It's even better than a premium Honda generator, because it's a Toyota generator.
     
  19. Priusdon57

    Priusdon57 Junior Member

    Joined:
    Jan 1, 2018
    6
    6
    0
    Location:
    Georgia
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Advanced
    These reply’s are all bad advice:

    My 2018 Prius Prime came with a paper that was attached to the charging cable it specifically says: Connecting the charging cable to an extension chord is strictly PROHIBITED. The extension chord may overheat and does not contain a GFCI. The leak detection function of the CCID (Charging Circuit Interrupting Device) may not operate correctly. The CCID is the box that has the 3 lights on it.
     
  20. Rob43

    Rob43 Senior Member

    Joined:
    Sep 24, 2014
    1,070
    736
    0
    Location:
    VA, BMW Race Car, BMW R1200R, BMW 330Ci, Ford F350
    Vehicle:
    2013 Prius v wagon
    Model:
    Prime Advanced
    The Toyota legal department NEEDS to add warning labels like that to prevent (not so smart people) someone from using a ~50 ft long 18 AWG extension cord for charging.


    Rob43
     
Loading...