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Any Solutions for 30/24 amp charging?

Discussion in 'Model S: Battery & Charging' started by BobbyG, Apr 16, 2016.

  1. BobbyG

    BobbyG Member

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    Several recent posts and Tesla staff have confirmed that since Tesla is no longer making the 14-30 adapters available, users who have a 30A source are left few safe options including:
    • Spending $500+ on a wall charger set to the 24A cont. load limit and looking for destination chargers instead of using friends/family while on the road
    • Using the 14-50 adapter and dialing the current down to 24A on the touchscreen and hoping that a firmware update doesn't reset this limit to the 40A allowable with the 14-50 (my understanding is that there is no way to know when updates will occur)
    • Hoping that I can find a Tesla 14-30 adapter either at a Service Center or online somewhere.
    None of these options are preferable, and I'm trying to communicate with Tesla accordingly. Given the prevalence of 30 amp outlets, I do not understand why they are creating this issue. Has anyone found another way to safely and easily charge with a 30 amp source?
     
  2. BobbyG

    BobbyG Member

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    To add to my own post: Here's one idea I'm kicking around. Given that the problem with needing to reset the limit in the car, I'm wondering if adding a couple of in-line 25 amp fuses to the cord set up would do the trick. They are relatively cheap (~$2/ea), wouldn't blow very often, and would add a layer of protection for the car and the house. Thoughts?
     
  3. TexasEV

    TexasEV Active Member

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    30A outlets aren't as useful as you may think when traveling. Most dryer outlets aren't within reach of where you can park the car. If you have a 30A source that you would use every day at your house I would recommend the convenience of the HPWC. It's really a small expense relative to the price of the car.

    If there is a relative's house out of town that you visit frequently, I would suggest installing a 14-50 outlet in their garage. That's what I did.
     
  4. DCGOO

    DCGOO Member

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    Not really related to your question, but all software updates are queued up, displayed on the console, and must be accepted before they are installed. I cannot imagine not being aware of one on the way in. After it is installed it is announced with the release notes. They typically take around 90 minutes to install, during which time you cannot drive the car.

    The bigger problem is inadvertently dismissing one, rather then scheduling it for later. Who knows when you will get another chance at it.

    Bigger problem if you have multiple regular drivers. "...oh yeah I saw something about update something. I ignored it so I could change the radio."
     
  5. Petra

    Petra Member

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    Yes, it's frustrating and annoying that they've canned the NEMA 14-30 and 10-30 adapters. I was fortunate enough to snag a 10-30 adapter before they canned them, which I use to charge while visiting my in-laws. The setup I use at home is a self-built EVSE, with brains from the OpenEVSE project, that runs off of a NEMA 6-30 outlet.

    I leave a 25' NEMA 10-30 extension cord hanging in the garage at my in-laws' place, park in the driveway, and charge using their dryer outlet whenever I'm visiting (usually 4-6 times a year). It's not an ideal solution, but it works great and makes taking the Model S up there convenient. Installing a 14-50 outlet isn't always a viable option. In the case of my in-laws, installing a 14-50 outlet would require a panel and service upgrade (normal house built in the 70's in the SF bay area) and PG&E quoted something like $20k for the service upgrade alone. The HPWC may be cheap compared to the price of the car, but you're still asking people to spend even more money when their existing plugs and the included UMC should be able to do the job.

    Killing off the 30A adapters for the UMC was, to me, a poor decision because there are a lot of potential customers who are in a situation similar to my in-laws--easy, cheap charging could be had through the UMC with a 30A adapter. The Model 3 launch may make this more of an issue in the long run.
     
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  6. linkster

    linkster Member

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    I actually use my 10-30 and 14-30 UMC adapters quite often at friends and relatives houses on my stretched 50' UMC. IMO, Tesla is going to have to re-issue these UMC adapters due to demand and potential safety issues.

    btw, an owner has a 10-30 listed
    for sale in the classified section. I think he is asking double the original price (I would gladly pay $90 if I needed one)
     
  7. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Occasionally, the car will be "off" on its GPS tracking as well and can recognize your home as a slightly different address, which can then cause the charging current to reset to default.

    I've given my opinion to Tesla numerous times that their adapter selections need to be broader. I've even offered to take their designs under some type of agreement and have them manufactured, if they didn't want to do it.
     
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  8. SomeJoe7777

    SomeJoe7777 Marginally-Known Member

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    Is there some type of trademark or copyright issue if someone were to reverse-engineer the UMC adapters and manufacture them? Is there a safety or UL-listing issue?
     
  9. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    There are the murky waters of design patents - if any exist - but that's about it. No real safety issue if designed and manufactured properly. As far as listing goes, anyone can have the product listed if they go through the process.
     
  10. efusco

    efusco Moderator - Model S & X forums

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    I've purchased several items from this place that work fine. You can put in the appropriate 30amp outlet and leave this adapter cord plugged in full time then plug your NEMA-14-50 UMC into that.
    For Tesla Model S
    [​IMG]
     
  11. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    That photograph shows precisely the problems with home-made adapters. That's a 6-30 to 14-50 adapter. It has no neutral conductor. If someone tries to use that for an RV, they will very likely damage a number of appliances in the RV (or commit a pretty serious safety problem by allowing return current to run via ground). There is no visible label to warn others that there is no neutral. Either they've connected the neutral to the ground pin (a GIANT no-no), or it's left disconnected.

    Such an adapter needs to be labeled "FOR TESLA CHARGING ONLY -- NO NEUTRAL -- DO NOT USE FOR ANY OTHER APPLICATION"

    In addition, all the same warnings for overcurrent protection apply, with the car potentially resetting its charging current. Never set it to more than 24A and pray it doesn't reset on updates or incorrect location sensing.
     
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  12. SomeJoe7777

    SomeJoe7777 Marginally-Known Member

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    I'm tempted to take one apart to find out how the current limit is signaled. I'm betting it's passive, e.g. just a resistance between the signaling pin and ground. If the resistances corresponding to the current limits can be mapped out, these can probably be duplicated and made for any outlet, including international styles.
     
  13. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    It's known to be a resistor. Another thread somewhere on these forums lists the resistances needed to signal the UMC.
     
  14. csshih

    csshih whirrrr

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    Spare UMC Availability this post has some information.
     
  15. Brass Guy

    Brass Guy Member

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    I've made this point on other threads too:
    You know how in certain faults (it happens to me sometimes) the car reduces the max current from 40A to 30A?
    On occasion I have to charge on a 30A outlet. I made my own adapter and dial back the current to 24A in the car. One time that faulted (a brief power interruption) and the car set the current to 30A, 75% of the 40A signaled by the adapter.
    It was a while ago so I don't know if one of the v7 updates changed that, but dialing back is far from fool-proof.

    Without any Tesla 30A adapters, there's no good way to use a 30A outlet.

    The resistor is between the ground and signal pins of the adapter.
    I saw these numbers on the forum a couple of years ago and saved them, but don't know if they're accurate.
    40A - 9.08k ohms
    24A - 33.16k ohms
    16A - 75k ohms
    12A - 140k ohms

    Unfortunately, to decrease the current signal you need to increase the resistance. It'd be easy to decrease the resistance, so that means starting with a lower rated adapter. You can change a 5-15 to a 5-20 by adding 160k ohms in parallel. That I wouldn't mind experimenting with.
    You could change the 5-15 signal to 30A signal (24A draw) by adding about 44k ohms in parallel, then make a "Tesla special" adapter to go from a x-30 outlet to a 5-15 socket; but I'd expect the 5-15 adapter to melt or start a fire. Or even the 5-15 receptacle at double its rating.

    If you could insulate the signal pin on the 14-50, and add your own 33k ohm resistor to take its place, then a 14-50 to x-30 adapter would work. I wonder if you could get a thin insulating sleeve in there.
     
  16. ChrisPDX

    ChrisPDX Member

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    I've thought about this myself. I've cut the neutral pin off my spare 14-50 adapter (the original pre-recall one I never sent back), but have to manually turn down the current on the car. If I could somehow add approximately 24k ohm resister in series to the signal pin, I would have a proper 14-30 plug. It could plug into either 30/50 amp, and run at a safe 24 amp draw. No adapter either! If I could figure out a simple way to do that, then I could probably have a nice little side business converting 14-50s to 14-30/50s. :)
     
  17. brkaus

    brkaus Member

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    I feel like someone should manufacture a pass through block or even a 14-50 alternative that has a dial switch to set the current.

    Which side of the UMC to the people that extend the UMC modify? Perhaps patch into the wire...

    If I remember correctly, the UMC is potted so not much could be done there.
     
  18. TexasEV

    TexasEV Active Member

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    Even simpler would be for Tesla to start making 14-30 UMC adapters again. Someone at Tesla reads the forums so they must see there is demand for it, and it would be safer than any of the kludges being discussed here which would benefit Tesla as well as the owners. So why aren't they?
     
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  19. brkaus

    brkaus Member

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    YES!!!
     
  20. Thomas Allen

    Thomas Allen Member

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