Tesla Car Charger???

wwhitney

Senior Member
Location
Berkeley, CA
Did I stutter, or do you have a misapprehension of the word, "credit"? And no, not to farmers, but to the fossil fuel users whose demand for energy is supplying free fertilizer to the Ag sector of the economy.
If you feel that fossil fuel users should get a credit for the supposed agricultural benefits of putting CO2 into the atmosphere, then obviously the recipient of that benefit should pay for that credit. So you'd be taxing farmers to subsidize fossil fuel users.

For a free market to work effectively, all the benefits and costs need to be interalized into the market. Otherwise, you get a market failure like we have now.

Cheers, Wayne
 

Rampage_Rick

Senior Member
Look at Hawaii. It's one of the few places in the US to have gotten so much electricity from diesel generators (because of being all islands), and their electricity is consequently wildly expensive by mainland standards. It's so much so that HECO became the first utility to have to refuse additional solar installations for a while and adopt new smart grid standards to move forward with additional solar. Solar with batteries is already completely competitive there, and they will probably be the first state to have true smart grids installed and get a majority of their energy from solar.
Distributed solar is obviously working there, but lack of storage is certainly a bottleneck. Pumped storage hydroelectricity seems like a feasible answer, and might be economically viable if electricity is really that expensive.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Yep, other than the choice of the output connector. That's just a mechanical difference, the electrical standard of the connection is the same. Tesla sells a mechanical adapter that will let you plug a J1772 connector into a Tesla.

Cheers, Wayne

Wayne, I am sorry but I still don't get it. I am trying to understand-- First, I am told that all cars have the charger built in. I don't understand that because are the charging stations not chargers? Why would you need them if the car has it built it. I see the Tesla has it built in as there is just a cord that plugs into a standard outlet from the house or a larger circuit without an external charger.

Do you see my confusion? I am obviously missing something
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
For a free market to work effectively, all the benefits and costs need to be interalized into the market. Otherwise, you get a market failure like we have now.
Diogenes would have had an easier time finding an honest man than a free market. In every market the more moneyed interests use their economic power to engage in manipulative practices to tilt the table more in their direction.
 

FionaZuppa

Senior Member
Location
AZ
Considering we've used an estimated 1 or 2 thirds of 'ultimately recoverable' resources in only the last 150 years or so, that seems like a wildly outlandish estimate, regardless of climate questions.

Considering that most places do not get much electricity from oil, that's a fairly nonsensical paragraph. Look at Hawaii. It's one of the few places in the US to have gotten so much electricity from diesel generators (because of being all islands), and their electricity is consequently wildly expensive by mainland standards. It's so much so that HECO became the first utility to have to refuse additional solar installations for a while and adopt new smart grid standards to move forward with additional solar. Solar with batteries is already completely competitive there, and they will probably be the first state to have true smart grids installed and get a majority of their energy from solar.
i dont quite follow about Hawaii. most places dont get power sourced from oil, but then you say Hawaii is mostly diesel, thus my confusion.
and Hawaii has grid power that runs from batteries at night? thats a lot of batteries and a lot of inverters. is it showcased on "how do they do it"?
 

wwhitney

Senior Member
Location
Berkeley, CA
Wayne, I am sorry but I still don't get it. I am trying to understand-- First, I am told that all cars have the charger built in.
Indeed they do. For regular charging, the vehicle is getting its power as 120-240V AC, and the electronics to convert that to the DC voltage needed to charge the battery are onboard the car. Some electric cars from a decade or two ago actually had a retractable cord that you just plug into a 120V/15 amp circuit. Some really inexpensive Neighborhood Electric Vehicles (= EV limited to 25-35 mph) may still use that arrangement.

There's two problems with that method of getting AC to the car. One is of course that the power available from 120V/15 amps is quite limited, although that could be addressed by using a higher rated NEMA plug. The other is that NEMA plugs and receptacles typically are not rated for multiple daily insertion/removal cycles.

So eventually car manufacturers came together to adopt the J1772 standard. It uses a mechanical plug/receptacle that is rated for the many insertion cycles required (Tesla uses their own proprietary plug/receptacle but otherwise follows J1772). It also uses a couple of signalling wires to implement a simple protocol to (a) allow the charging station to advertise the maximum allowed current the car may draw and (b) require the car to tell the charging station it is ready for power before the charging station makes the power lines hot. That keeps the charge cord unpowered unless the the J1772 handle is plugged in and the car is charging.

I don't understand that because are the charging stations not chargers?
Nope, not chargers, basically just smart switches. They have some electronics built in to handle the above protocol and maybe some bells and whistles like a timer. They have a contactor built-in to allow the cord to only be energized while the car is charging. And they have GFCI hardware as required by NEC Article 625.

I see the Tesla has it built in as there is just a cord that plugs into a standard outlet from the house or a larger circuit without an external charger.
Functionally, that Tesla "fat cord" is identical to the wall mounted versions you see. The guts are the same. The only reason the wall-mounted versions are bigger is that there's no need to optimize for physical size with a fixed charging station. Plus some of them use the case as a cord rack. The wall mounted charging stations may be hard-wired or may be cord and plug-connected. Some of the cord-and-plug connected ones are even small enough to be semi-portable.

I hope that helps.

Cheers, Wayne
 
i dont quite follow about Hawaii. most places dont get power sourced from oil, but then you say Hawaii is mostly diesel, thus my confusion.
I really never gave the issue of making electricity in Hawaii a second thought before this thread.

According to Wiki, there is only one coal fired power plant in the entire state, and the state has banned the production of new coal plants.

https://en.wikipedia.org/wiki/Energy_in_Hawaii

In 2008 Hawaii's primary energy consumption by source was:

  • 85.0% petroleum, down from 99.7% in 1960
  • 7.1% coal
  • 0.1% natural gas
  • 7.8% renewable energy

Compare this to the state I live in:

Michigan's energy mix in 2009 was 66% coal, 22% nuclear, 8% natural gas and 3% renewables.[SUP][3][/SUP]

This is what electrical energy cost in Hawaii in 2011. Yikes.

In October, on Lanai, residential rates were 44 cents a kwh; on Molokai and Kauai, 42 cents a kwh; on the Big Island, 40 cents a kwh; and on Maui, 35 cents a kwh, according to electric company data.


 

Rampage_Rick

Senior Member
Wayne, I am sorry but I still don't get it. I am trying to understand-- First, I am told that all cars have the charger built in. I don't understand that because are the charging stations not chargers? Why would you need them if the car has it built it. I see the Tesla has it built in as there is just a cord that plugs into a standard outlet from the house or a larger circuit without an external charger.

Do you see my confusion? I am obviously missing something
EV charging is inherently a 2-part system. The charger itself is a part of the car, and the "charging station" or EVSE is basically just safety equipment. The point of the EVSE is to prevent users from being exposed to live terminals and to tell the car the limits on how much current can be drawn. It's 240V in / 240V out, no power conversion is taking place. Even if you plugged 240V straight into the car's inlet it wouldn't begin charging because it wouldn't see the proper signals from it's EVSE counterpart.

63076-fig2.jpg

The Tesla "cord" is no different than every other "charging station" except they've built it into a very compact and sleek package.
 

FionaZuppa

Senior Member
Location
AZ
for the EVSE, why would it need to be any more complicated than a control signal from car to station? a simple 2 or 5vdc control voltage that when the station cord connector plugs into the car the control voltage signals the station to power-on, which is completely independent of supply voltage.
 

iwire

Moderator
Staff member
Location
Massachusetts
for the EVSE, why would it need to be any more complicated than a control signal from car to station? a simple 2 or 5vdc control voltage that when the station cord connector plugs into the car the control voltage signals the station to power-on, which is completely independent of supply voltage.
It is more than on and off, it also tells the charger how much current it can draw from the cord.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Thank you Wayne & Rick..... That takes care of my confusion-- at least on that issue :D Thinking the big station was a charger was the problem.
 

FionaZuppa

Senior Member
Location
AZ
It is more than on and off, it also tells the charger how much current it can draw from the cord.
sounds to me like charging stations need to be standardized to something like 240v/50A or 120v/20A that have amp clamps so the car cant short out the station, then you would not need all that extra electronics.
 

junkhound

Senior Member
Location
Renton, WA
then you would not need all that extra electronics

uh, Li batteries need a charge equalization (or voltage limiter) across each cell for proper charging. Cannot do that with something 'on the wall' unless you bring # of cells-1 extra wires out of the battery pack to the charging unit.
 

iwire

Moderator
Staff member
Location
Massachusetts
sounds to me like charging stations need to be standardized to something like 240v/50A or 120v/20A that have amp clamps so the car cant short out the station, then you would not need all that extra electronics.
We get it, an electric car hurt you and now you dislike them. :lol:
 

Rampage_Rick

Senior Member
It is more than on and off, it also tells the charger how much current it can draw from the cord.
Another part of the spec allows the vehicle to specify that ventilation is required (not applicable on modern vehicles, but included to allow for lead-acid batteries which release hydrogen while charging) If the vehicle requests ventilation but the EVSE isn't configured for it, no charging will occur.

https://en.wikipedia.org/wiki/SAE_J1772
 

FionaZuppa

Senior Member
Location
AZ
then you would not need all that extra electronics

uh, Li batteries need a charge equalization (or voltage limiter) across each cell for proper charging. Cannot do that with something 'on the wall' unless you bring # of cells-1 extra wires out of the battery pack to the charging unit.
yes, the team here already established that the charger portion is in the car, and i was not meaning to remove all of the charging circuitry. a basic LM regulator or even a zener can clamp the voltage.....


We get it, an electric car hurt you and now you dislike them. :lol:
no, the ROI for EV just is not on same field as gasoline vehicle. when EV gets somewhat realistically closer i might buy a EV. the novelty of EV just isnt my type of novelty.
 
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