TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

wireless induction charging

Discussion in 'Model S: Battery & Charging' started by 30seconds, Aug 7, 2013.

  1. 30seconds

    30seconds Active Member

    Joined:
    Feb 28, 2013
    Messages:
    1,143
    Location:
    SF
  2. dhrivnak

    dhrivnak Active Member

    Joined:
    Jan 8, 2011
    Messages:
    2,150
    Location:
    NE Tennessee
    For me i wonder why bother as with inductive charging one loses at least 10% in efficiency and it takes less than 5 sec to plug in.
     
  3. WarpedOne

    WarpedOne Supreme Premier

    Joined:
    Aug 17, 2006
    Messages:
    2,661
    Location:
    Slovenia, Europe
    For me I wonder why bother as with automatic transmission one loses at least 10% in efficiency and it takes less than 5 sec to move the stick.

    Doing nothing is always easier/more elegant than doing something. Inductive charging is low power so there is no big need for active battery cooling. Because of this it could be more efficient than higher power conductive charging with active battery cooling,.
     
  4. derekt75

    derekt75 Member

    Joined:
    Jul 16, 2012
    Messages:
    592
    Location:
    San Jose, CA
    :)

    That seems like a big drawback.
    I'm not sure low power is necessarily a required element of inductive charging, though. The article mentions 100 kW. I don't think that fits anyone's definition of low power. :)
    People are afraid of the radiation out of a 1 W cell phone or a 20 W cell tower. I wonder why nobody's afraid of the ground radiating 100,000 W. I guess I'll never understand what makes people afraid, though....

    Perhaps.
    I think so far, the reality has been that lower power charging (< 5 kW) has been less efficient in Teslas than higher power charging (> 20 kW).
    Regardless, if lower power charging were better, you could just dial down the power sent through a wire to realize the same gains without worrying about trying to keep all the energy going just to the bus and nowhere else.
     
  5. Iz

    Iz EVs are here to stay

    Joined:
    Nov 22, 2006
    Messages:
    1,074
    Location:
    New York
    #5 Iz, Aug 7, 2013
    Last edited: Aug 11, 2013
    While the technology is just starting, it will be a key factor when selling EVs in urban areas. Those who live in apartment buildings and cannot easily find a place to plug and charge will benefit from induction charging when parked on streets. When the bugs are eliminated it could be similar to a parking meter. Also eliminates potential vandalism to the charge connection.
     
  6. NigelM

    NigelM Recovering Member

    Joined:
    Apr 3, 2011
    Messages:
    13,257
    Location:
    Sarasota, FL
    Changed.
     
  7. RandyS

    RandyS Fan of Elon

    Joined:
    Jul 8, 2012
    Messages:
    360
    Location:
    San Diego
    I can see this being desirable by the operator of EV Fleets, as we already have some drivers who forget to plug in when they drive one of our company fleet EVs. And perhaps in the multi-unit development uses mentioned above. But in the garage where most people charge their EVs, I don't think the benefits are worth the cost. Plugging in is automatic and fast...Who wants a disk buried in their garage floor or surface mounted that you have to park right on top of? Not to mention the $$$ cost...

    No thanks..
     
  8. wraithnot

    wraithnot Model S VIN #5785

    Joined:
    Dec 16, 2012
    Messages:
    475
    Location:
    SF Bay Area
    This seems like a much better solution for electric buses and electric light rail than the overhead wires used by things like the San Francisco MUNI. I've seen MUNI bus drivers standing outside trying to reconnect their bus to the overhead wires with a long pole (hopefully insulated) on several occasions. This seems way too expensive for rural highways and suburban neighborhoods. But it might make sense for urban areas- especially areas where they already bother to put in overhead wires. Of course, as Derekt75 mentions, if people freak out about cell phone radiation and power lines, they'll probably REALLY freak out from inductive road charging.
     
  9. lloyds

    lloyds Member

    Joined:
    Apr 3, 2013
    Messages:
    890
    Location:
    Bay Area
    I do wonder what the potential health effects are with wireless charging.
     
  10. derekt75

    derekt75 Member

    Joined:
    Jul 16, 2012
    Messages:
    592
    Location:
    San Jose, CA
    Any damage would be heating damage, as RF radiation can't change DNA.
    So, it depends on how much they can ensure that the power goes where it's supposed to. If 10% of that 100 kW makes it into you, your flesh would get cooked, and it would be about as bad as hanging out in a microwave oven (i.e., bad.). At lower power levels, there might be some sensitive tissue that would be overheated. Chronic exposure might increase cancer risk, since it seems that whenever tissue is chronically damaged (e.g., acid reflux), cancer risk goes up.
    If only 0.05% of that 100 kW gets absorbed by your whole body, you might sweat imperceptibly more and there'd be no more harm done than sitting in the same room as a few light bulbs.

    I imagine they only try to blast out 100 kW when there's a bus on the platform, and when there's a bus on the platform, I imagine that does a good job at preventing the radiation from going elsewhere. and presumably, unlike a microwave oven, they probably choose a frequency that isn't absorbed well by water or fats, so hopefully the health risk is low.
    but if the system goofs and somehow blasts out 100 kW when there's naught but a person on top of the platform, I dunno but I'd guess that would be bad.
     
  11. Lump

    Lump Active Member

    Joined:
    Mar 31, 2013
    Messages:
    2,112
    Location:
    So. Cal.
  12. vfx

    vfx Well-Known Member

    Joined:
    Aug 18, 2006
    Messages:
    14,792
    Location:
    CA CA
  13. jchangyy

    jchangyy Member

    Joined:
    Nov 30, 2012
    Messages:
    194
    Location:
    CA
  14. captain_zap

    captain_zap Electron tamer

    Joined:
    Mar 27, 2012
    Messages:
    147
    Location:
    Redmond, WA
  15. efusco

    efusco Moderator - Model S & X forums

    Joined:
    Mar 29, 2009
    Messages:
    4,593
    Location:
    Nixa, Missouri, United States
    We early adopters can take a someone opinionated and limited view of the real world. Inductive charging makes a lot of sense in a lot of places.
    As we all know, our daily driving uses few miles that are easy to replace. Even a big day of local driving I rarely go over 70-80 miles at a time. The ability to just pull into my garage and not bother with the charging cable each and every day would be a pleasure. I don't have to worry about my wife or my kids (when they start driving) remembering to plug in. Hotels could install these sorts of chargers at a great convenience.

    Yes, I still want the option of using my HPWC to more rapidly top up when necessary, but there are enough times I was getting out of my car juggling a coffee mug, brief case, umbrella and various other items and then trying to plug in the car to save a trip inside and back out.

    IMO, induction charging can, and maybe should, become the norm and a HPWC (or whatever for other EVs) the added charge option for those who wish to have the ability to charge more rapidly and for travel locations. Anything we can do to continue to show that EVs are even more convenient and superior to gas vehicles is a good thing and eliminating the need to remember to plug in daily or multiple times daily is a good step.
     
  16. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    What charge rate are you assuming here?
     
  17. efusco

    efusco Moderator - Model S & X forums

    Joined:
    Mar 29, 2009
    Messages:
    4,593
    Location:
    Nixa, Missouri, United States
    didn't have a specific number in mind, maybe 10-15 mph.
     
  18. Raffy.Roma

    Raffy.Roma Active Member

    Joined:
    Jul 22, 2012
    Messages:
    3,209
    Location:
    Rome (Italy)
    IMO no health effects because of the low frequency of the electromagnetic field. Not even for a cat that for some reason would go under the car while charging. In fact the power of the electromagnetic field is proportional to the square of its frequency.
     
  19. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    Ok, so basically 1/3 to 1/2 the rate of a 14-50. Yah, I'd love that at home for daily charges without having to plug in.
     
  20. digitaltim

    digitaltim Sig737 VIN628

    Joined:
    May 2, 2012
    Messages:
    550
    Location:
    MD, USA
    One of my best friends 7-12th grade becomes CEO in March...I'll have to ping Steve.
     

Share This Page