Clarification wanted on how quick charge works

[DarkStar]

Doesn't make sense to me. How does the charging station know what the charge states of the battery cells are? I suppose it could make a rough guess based on a drop in current flowing. However, the Battery Management System in the car knows much more about the charge states, so if an 80% shutoff is occurring it would make more sense to me for the BMS to shut off to prolong battery life.

Unlike AC L2 charging (J1772), there is data communication between the car and the DC Charger. I don't know what the protocol for that data is (yet), but it likely shares the state of charge and other details useful to the DC Charger in ending the charge.

CHAdeMO is actually kinda the opposite of J1772. Instead of the EVSE telling the car the maximum amperage it can draw, the car tells the DC Quick Charge the voltage and amperage to send to the car. As the vehicle charges it sends new signals to the DC Quick Charger to reduce the amperage.

The current way it works is you'll go from 0-80% in about 25 minutes. It will take an additional 15-20 minutes to go from 80-100%, providing a 0-100% charge in 40-45 minutes!

What people are forgetting is that the DC Quick Chargers do exactly what the internal charger does on the vehicle, except they can provide a higher amperage (same voltage). Personally, Nissan should offer additional control so I could punch in that I want a certain percentage of charge in a specified time-frame. No need to charge at a 2C (a designation of a lipo charge rate) rate when 1C (half the amperage of 2C) will work for me.

 

[LEAFfan]

Also remember that once the charge stations go $pay$, you will pay the exact same price for a partial charge, or full charge.

Maybe not. Gas stations don't ask every customer to pay the same amount. Could be that fast charging customers will pay accoring to how many kilowatt-hours of electricity the charger dispensed...

They can't charge you for the electrons; only electric utilities can do that. If and when they decide to charge, they will have to charge you a set fee for the space.

 

[tps]

They can't charge you for the electrons; only electric utilities can do that. If and when they decide to charge, they will have to charge you a set fee for the space.

How long do you seriously think that will last? That's like saying gas stations can't charge for the molecules of gas, but they have to charge a set fee for stopping by the pump. I think lawmakers will get smart with EV charging sooner rather than later.

 

[Coffee_Slurry]

They can't charge you for the electrons; only electric utilities can do that. If and when they decide to charge, they will have to charge you a set fee for the space.

How long do you seriously think that will last? That's like saying gas stations can't charge for the molecules of gas, but they have to charge a set fee for stopping by the pump. I think lawmakers will get smart with EV charging sooner rather than later.

There is a whole organizational infrastructure set up to ensure fair gas pump metering and consumer protection:
http://www.agmkt.state.ny.us/WM/WMHome.html

This doesn't (yet) exist for electricity, outside of the public utilities.

My local co-location facility ran afoul of this law when they tried to surcharge computer clients based on wattage. CPUC shut them down, saying they can not resell electricity. They tried a few different schemes, each one prohibited. Eventually they conceded that they can only install a sensitive circuit breaker to limit peak consumption to some number of amps.

My guess is we will see something like "metered parking", where you pay by the minute to park near the DC charger.

 

[BetaMark]

wow, no comments on my little joke from last night. I was a little tired, and got a little creative. There is a little truth to the story, but the real situation is far more complicated, and the analogy breaks down pretty quickly. I was about to hit cancel because the analogy broke down as I was typing, but decided to leave it in for some light humor.

LOL.. loved it Mike, even read it to the wife. Sorry I didn't respond sooner.

 

[tps]

My local co-location facility ran afoul of this law when they tried to surcharge computer clients based on wattage. CPUC shut them down, saying they can not resell electricity.

So I guess they expect the electric utility to give each client at the Colo his own meter, or do they expect each client to install their own PV on the rooftop... My Colo here in Philadelphia charges per month for "a circuit with a 20A breaker / 16A max draw", which is kind of an indirect way of charging for the power without actually measuring it.

Legislators need to get on the ball and fix these laws so they're more friendly to EV infrastructure, especially on the west coast where its installation is ramping up now.

 

[garygid]

1. In CA apparently the PU Commission has already changed the "law" (rule)
so that EV "filling stations" can actually sell electrical energy.

2. I thought I read that "Nissan" loosely described the last 20% of QC charging
as taking an additional 45 minutes, but it may have been a guess rather
than an accurate description of the QC implementation in the LEAF.

 

[BetaMark]

I feel for you. Most landlords are rather stingy about such things.
Maybe once you have the car, your employer would put a 20a outlet on an existing lighting circuit in the parking lot or something that works for you.
I am hoping my employer will do something if they will not put in a regular charging dock.

Looks like there's a glimmer of hope for me. I understand that ECOtality is launching a pilot program to install fast chargers at ARCO stations in and around the Los Angeles area. Hopefully this will extend to the San Fernando Valley.

 

[smkettner]

What would a person pay extra to have an assigned parking spot with 16a EVSE and free electricity?
$25, maybe $50 per month? I doubt it would be $100

 

[derkraut]

When the first guy enters the room there are 100 gals waiting to dance. Its easy for this guy to find a partner. The more guys that enter the room, the fewer partners there are and its harder for them to find a dance partner. At 80% there are now 180 people in the room and there are only 20 single gals left, the whole process begins to slow down as it is harder to find dance partners quickly when you enter the room.

Now Michael....that is a beautiful, and simple, and accurate description.