Plug & Charge Fail and the 80% Cliff is Real

[ajmartineau]

@hybrid2bev
Can you try plugging in at 81% or higher? Maybe we can trick it. Although I hear charging/preconditioning will be in the first OTA. So this isn't a big deal as it will be fixed by the time mine is here.

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[hybrid2bev]

@hybrid2bev
Can you try plugging in at 81% or higher? Maybe we can trick it. Although I hear charging/preconditioning will be in the first OTA. So this isn't a big deal as it will be fixed by the time mine is here.

I don't think we can trick it. I went to a 25 kW charger at 79%. It started out at 22 kW. When I unplugged about 20 minutes later at 81% it was pulling 6 kW.

I'm willing to try again after the OTA has been sent out.

 

[TheVirtualTim]

@hybrid2bev
Can you try plugging in at 81% or higher? Maybe we can trick it. Although I hear charging/preconditioning will be in the first OTA. So this isn't a big deal as it will be fixed by the time mine is here.

It is normal for any battery to charge slower as it approaches being fully charged. Forcing a high charge rate on it can result in a degradation of overall battery life.

If you look at apps like ABRP ... it's smarter to stop more often for shorter charger sessions that never exceed 80% state of charge than to try to stop less often and wait for a full charge. (The overall trip time of driving time + charging time is ultimately shorter if you do this.)

 

[SnBGC]

Just a friendly warning that each ChargePoint station sets their own prices, as "ChargePoint" just sells the chargers and runs the payment processing, the actual property owner is the one that buys the charger and sets pricing. Some are far more expensive than Electrify America, depending on what the property owner decides.

This is correct.
Pretty much exactly like a gasoline station.....free to set their own prices.

Many retailers are interested in programs where they can issue reward points redeemable for free charging. That is coming......but likely to be primarily for AC L2 stations.

Since we are on the subject.....
When it comes to AC L2 commercial ChargePoint stations, the owner has a wide variety of rate plans and charging speeds to choose from. It may be free until your car is finished and then you get charged an idle time fee for example. It might also be a FIFO or Round Robin charge method vs dedicated circuits for each machine. In each case, your app should communicate the charge speed and payment method. That is the idea with ChargePoint at least. Let's see how it plays out in real practice....

 

[sldave84]

Just a friendly warning that each ChargePoint station sets their own prices, as "ChargePoint" just sells the chargers and runs the payment processing, the actual property owner is the one that buys the charger and sets pricing. Some are far more expensive than Electrify America, depending on what the property owner decides.

Yeah I have been looking at a lot of them in the FordPass app. Some appear to be $12 just to sit and then the $.30-45 rate the OP showed. Likely won’t need much fast charging, but when I do I’ll be avoiding places where I would spend $25 or more for 60% charge

 

[SnBGC]

I don't think we can trick it. I went to a 25 kW charger at 79%. It started out at 22 kW. When I unplugged about 20 minutes later at 81% it was pulling 6 kW.

I'm willing to try again after the OTA has been sent out.

Agreed. You wont trick it....but it might charge a little quicker briefly. Depends on a bunch of things that are hard to control such as battery temp, charge gear temp, DC pin temp, ambient temp etc.

People seem to think the charge curve is a constant. That is just not the case when it comes to DCFCing.

 

[ajmartineau]

It is normal for any battery to charge slower as it approaches being fully charged. Forcing a high charge rate on it can result in a degradation of overall battery life.

If you look at apps like ABRP ... it's smarter to stop more often for shorter charger sessions that never exceed 80% state of charge than to try to stop less often and wait for a full charge. (The overall trip time of driving time + charging time is ultimately shorter if you do this.)

Thanks Tim!
I know about degradation and charger hoping. I've 100% BEV for almost 2 years. The MME will be my 3rd BEV in the driveway.
This is just an experiment to find the potential ceiling of the charge rate at a given percentage. I thought of this from the observation of multiple reviewers getting a short-term boost in speed when they plug in high into the pack.

 

[EVS]

I generally agree, although I wouldn't want EA rates to be artificially higher. They're simply higher because it costs a lot more to install and maintain DCFC chargers than it does home charging. It's proper to charge higher rates for something that costs more.

Even if they were the same price, there's still a big incentive to charge at home and a disincentive to charge at a public charger -- convenience. It's super convenient to plug in overnight at home and forget it. Probably the biggest single convenience of BEVs. But having to babysit a DCFC charge is a pain.

Oh, people don't always think rationally! Where I live, people used to go to malls and plug the car to a Tesla charger while they grab a coffee and sit somewhere reading or watching youtube video on the Tesla dashboard! People may be paying $500-700 a month for the lease. But if it is free, it just sets them into a different mode of thinking I guess. That's why Tesla got rid of free charging. I think people also have too much free time in this age and are looking for an excuse to go out sonewhere.

I've seen Teslas parked at public charging spots at chargers that were not even plugged in. Why? Because the EV charging spaces are the closest to the entrances. This is another issue right now. They can't be far due to the high power electric wiring needed. Hopefully the slow chargers are in the back.

I'd like EA to use the high rates to provide a high quality of service with 100 % up times. If need be, monitor the stations with video surveillance or an attendant, like the old days of full service gas stations. So when people arrive at a charger, they feel confident to get a charge in time.

But speaking of rates, even my home. off-peak rates are approaching $0.45/KWh cents due to tiered use. So I personally don't find 31-43 cents/KWh expensive. But I understand this is different for people in lower rate states or with a separate EV meter with PG&E or other ]utilities.

Getting 250 out of a 100% home or hotel L2 charge is probably pushing it, even in a RWD ER. Assuming it's at interstate speeds (which a 1000 RT usually is). By the time you adjust for high speed loss, leave 10% in the tank as a buffer, use some climate control, and adjust for less-than-perfect temps, ~220 is probably more realistic. ~200 for AWD. And there's probably not a charger right at that limit, forcing you to stop 10 or 20 or 30 miles sooner. The shorter legs commense at that point.

For my frequent road trip in my AWD ER, the pattern looks like it will be roughly 180-100-100-100... Some of that is simply because that's where the chargers are spaced though. Could probably reach 140 on those subsequent legs but there's not chargers there.

I was oversimplifying a bit. Most people probably spend only 5-10% of their miles in road trips, and even those road trips are much shorter. Your situation seems to be not so common. Perhaps when you pick your hotels for overnight stays, you have to be more selective and pick the ones with L2 chargers. How far are you traveling on these trips? How many miles do you travel per day on such trips?

 

[ClaudeMach-E]

Probably annual vehicle registration fees, rewarding high mileage drivers and penalizing low mileage folks. I suspect with my MME I will accrue greater annual mileage. ?

I've heard of a per km/mi tax, but how do they control that I don't remember but it's in the mill of thinkers.

 

[Woeo]

Ok, re-doing the Maths with that assumption:

65 KWHs delivered at $0.31 USD per KWh = $20.15

Reverse-engineering the tax from the OP's screenshot is $1.68 / $27.95 = 6%.

$20.15 + $1.21 tax = $21.36 total

$21.36 / 1.929 = $11.07 USD per gallon-of-gas equivalent. Still, what, 3 - 4x current price of gasoline (in the US) at the time of this post. Ouch.

You are purposefully making a disingenuous comparison. 65 kilowatts will deliver roughly 3x65=195 miles. A 30 mpg ice vehicle would require 6.5 gallons of gas at ~$2.50 per gallon, approx. $19.25.

 

[ClaudeMach-E]

So here we have 50kw 100kw and 150kw chargers. For the small amount of time that the car reaches 150, would it make more sense to go to a 50 or 100kw charger pay less but get a more linear curve or would the curve be the same for the slower chargers? In other words if you go to a 50kw would it stay at 50kw or would you end up at like 33kw

I guess we'll have to experiment this ourselfes when we get our cars.

 

[kdryden99]

I guess we'll have to experiment this ourselfes when we get our cars.

looks like it. You'd figure that if its because of heat management that at lower charging levels you might get a more stable and linear charge. It might be faster than one that fluctuates at higher levels

 

[TheSteelRider]

You are purposefully making a disingenuous comparison. 65 kilowatts will deliver roughly 3x65=195 miles. A 30 mpg ice vehicle would require 6.5 gallons of gas at ~$2.50 per gallon, approx. $19.25.

Nope it was an honest mistake. Fellow community members reminded me of the efficiency differences that I had not accounted for just a couple posts later.

Good point. Let's call it 3x more efficient than the average ICE, so at that price it is basically on-par with a $ per mile cost.

I'll forgive the accusatory tone, but would like to request perhaps in the future pausing to consider that sometimes folk make simple accidental mistakes, and a simple correction goes farther than an accusation.

 

[ClaudeMach-E]

looks like it. You'd figure that if its because of heat management that at lower charging levels you might get a more stable and linear charge. It might be faster than one that fluctuates at higher levels

And apparently the first OTA will had the capability to precondition the battery if you set a charger has destination.

 

[Shayne]

I've heard of a per km/mi tax, but how do they control that I don't remember but it's in the mill of thinkers.

You need to renew your plates. At that time you have to provide your odometer reading. They could charge you for the new plate sticker based on miles put on your EV since your last plate renewal. It could be variable and a lot more for plates in the future to maintain our frost heaved roads.

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