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The Power of CHAdeMO

Discussion in 'Model S: Battery & Charging' started by Cottonwood, Feb 8, 2015.

  1. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    With the CHAdeMO adapter shipping, I decided to try to see how much time it would take to get a charge in an 85 with a CHAdeMO charger.

    Many CHAdeMO chargers are limited to 50 kW and 125 Amps. In addition, the Tesla CHAdeMO adapter is limited to 125 Amps. I put this together with Battery charge state vs battery Voltage. Assuming that charge current was limited to 125 Amps or the Supercharger current, whichever is less, I then calculated CHAdeMo charge power and rated mph charge rate.

    My raw and not well explained calculations are at Supercharger 2015-02-05 - Google Sheets

    Here are some interesting results:

    1. Starting charge power at 360 Volts is about 45 kW and 150 mph.
    2. Max charge rate before the 85 battery current limit kicks in at 393 Volts is 49 kW and 164 mph.
    3. Time to reach 80% SoC from 0% via CHAdeMO is 1:22
    4. Tesla claims Supercharger time of 0:40 to reach 80% from 0%.
    5. On this slightly cold evening, it took me 0:50 to reach 80% from 0% on the Silverthorne Supercharger.
    6. A 50 kW CHAdeMO only takes an extra 42 minutes over a Supercharger to get to 80% and more, and 32 minutes more than my cool evening example.

    A 50 kW CHAdeMO needs about 56 kW AC in or a breaker (80% continuous load) of 85 Amps, 3-phase, 480 Volts. For locations with only 208 Volts, the need is 200 Amps at 208 with a step up transformer to 480. This is serious power, but within reason.

    Given this, and the installed cost of a CHAdeMO Charger being somewhere in the range of $15k to $30k, it may be interesting to consider crowd funding some CHAdeMO chargers on underserved routes where it will be a long time for Tesla to get Superchargers deployed.
     
  2. rickgt

    rickgt Enthusiast owner/member

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    I like the way you're thinking about this... Only problem with crowd funding, is the real estate aspect of locating the charger...
     
  3. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    I agree!

    I was assuming that a willing host site could be found, then do the crowd funding to pay for the install. This is really an upscaling of what has been done at North Central Washington high amperage L2 Charging Project. The difference is putting in a CHAdeMO rather than a HAL2.
     
  4. apacheguy

    apacheguy Sig 255, VIN 320

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    And what % SOC is that exactly?

    Eyeballing it from the taper curve I posted in an other thread, it should be 70-75%
     
  5. cpa

    cpa Member

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    Excellent idea! Presumably this installation would be available to Leafs and any future BEV with CHAdeMO capabilities. Then we owners would have to purchase the adapter or be able to rent one from someone for our journey.

    So, Cottonwood, your master plan would be to install these along the more leisurely and scenic routes like US50 across Nevada, US40 across northern Utah and Colorado, US2 from Spokane up through the Idaho panhandle and across northern Montana, North Dakota and Minnesota? Also perhaps to enhance north-south routes on secondary highways between interstates to enable one to travel from I94 south to I40 without having to take a longer route on an interstate? It would be interesting to take the 2016 Supercharger map on Tesla's website and identify possible locations for these grass-roots CHAdeMO locations! Happy to help :smile:
     
  6. Benjamin Brooks

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    I suspect these numbers are a little bit optimistic for the random 50kW CHAdeMO chargers people encounter in the wild here in USA.
    Specifically, I think CHAdeMO charger thermals will limit sustained power (or, current) output during the 0 to 80% recharge... my (seat of the pants) estimation is people should budget at least 2 hours for a CHAdeMO charge to get an 85kWh battery from nearly empty to 80-90% SoC.
    Time will tell, we should have real life numbers soon...

     
  7. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Very good estimate on my charge with my data, the 125 Amp point was hit at 73.3% SoC.
     
  8. RiverBrick

    RiverBrick Active Member

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    Crowdfunding CHAdeMO is an interesting idea, but I think some of the assumptions are a bit optimistic.

    CHAdeMO in the wild that are supposed to be 50kW out tend to provide ~46kW.
    $15,000-$30,000 seems low. Are you hoping they'll retroactively offer the 30% tax rebate again? Otherwise, for that price range you may only be able to get a 25 kW unit. The Nissan branded station is cheap too, but only 43 kW and very unreliable.
    A small business hosting a 50 kW station will have to find a solution to avoid paying exorbinant "power on demand" fees.
     
  9. David99

    David99 Active Member

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    I think the biggest issue with installing and keeping chargers maintained is that it's hard to make any money with that as a business model. The Chargepoint CEO pretty much said that's impossible to have a successful business selling electricity. It's kind of like WiFi. You can't sell it as a per use service any more, so it's mostly now a free courtesy service.

    The power requirement makes it impossible to install it without a serious wiring and transformer nearby. I think that's where grid storage batteries can come in handy. They are charged from a normal 240/208 Volt source that is available anywhere and the DC charger can draw high power from these. Of course it would only work in locations where the charger isn't used 24/7. But I think the cost of a grid storage battery would be less than a major power upgrade by the power utility company (new transformer, new wiring, digging up ground, ...) Maybe Tesla will some day offer home Superchargers that are powered by a storage battery. Sorry a little OT...
     
  10. scott2613

    scott2613 Member

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    I should have our CHAdeMO/SAE combo 50kW DC fast charger installation complete sometime in April. We currently have an HPWC and a Clipper Creek CS 100 75A J1772 all are solar powered with a 72kW array.
     
  11. Cosmacelf

    Cosmacelf Active Member

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    More details please? Sounds very interesting!
     
  12. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    I would to hear details of your experiences here or via private communications. Specific details of interest are:

    • Choice of Make/Model, and why.
    • Why Combo?
    • Costs of equipment and installation.
    • Expected electrical costs. Energy rates and demand rates.
    • Your motivation.
    • Any other relevant info/thoughts.
     

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