Chevy Bolt will have 238 miles of range, EPA says !!

[Zoomit]

This implies a 7.7 kW on board charger (32 amps @ 240v = 7.68 kW)

I'm not an EE, but I think all of the on board chargers spec'd between 6.6 and 7.7 kW are functionally the same. The only difference is the assumed input voltage. The circuits have to be designed to handle anything between 208V (three-phase) and 240V (split-phase) and at 32A that range is 6.6kW to 7.7kW. So the actual charging power will be driven by, among other things, the installation type (three-phase vs split-phase) and the utilization voltage at that time.

In addition, the J1772 pilot waveform will set the duty cycle to 50% which equals 30A. So even if the utilization voltage is 240V, the power supplied to the charger will be limited to 7.2kW (240Vx30A).

Download the manuals from two Clipper Creek EVSEs and look at their specs as an example:

HCS-40 EVSE, 32 Amp Level 2, 240V, 25 ft cable EV Charging Station
https://store.clippercreek.com/index.php?route=product/product/download&download_id=14

CS-40, 32 Amp EV Charging Station
https://store.clippercreek.com/index.php?route=product/product/download&download_id=20

The HCS-40 can provide power at 32A for 7.7kW BUT "Note that the maximum current for the vehicle is set by the
duty cycle of the Pilot waveform." (page 24)

Then look at the CS-40 specs. "The maximum current for the vehicle is 30A, set by the duty cycle of the Pilot waveform...Vehicles will be
limited to 30A. At 240V, this will be about 7.2 KW." (page 15 [18])

And these EVSE are both 240V, 32A. So I conclude that the power to the Bolt EV's charger, after the J1772 handshake, will never be greater than 7.2kW. If you or others can correct or add to this, I would very much like the feedback.

 

[litesong]

I'm just skeptical.....

My two Elantras, bad-mouthed for poor mpg, have given 43 & 45+mpg. My Bolt range will probably hover beyond 250-260miles. I'm skeptical your normal EPA Bolt range will be like-wise.

 

[SeanNelson]

This implies a 7.7 kW on board charger (32 amps @ 240v = 7.68 kW)

I'm not an EE, but I think all of the on board chargers spec'd between 6.6 and 7.7 kW are functionally the same.
:
:
Then look at the CS-40 specs. "The maximum current for the vehicle is 30A, set by the duty cycle of the Pilot waveform...Vehicles will be
limited to 30A. At 240V, this will be about 7.2 KW." (page 15 [18])

I'm no EE either, but the Wikipedia article on the CCS standard says that in addition to a 50% duty cycle requesting 30A it also states that the duty cycle is variable, in small increments between 0.6A and 48A - so i don't see any reason why the car couldn't request 32A instead of just 30A. It would just be up to the owner to buy a charger that could put out the extra 2A, wouldn't it?

 

[new2evs]

Some of you really know your stuff. Hats off to you

 

[roundpeg]

I'm no EE either, but the Wikipedia article on the CCS standard says that in addition to a 50% duty cycle requesting 30A it also states that the duty cycle is variable, in small increments between 0.6A and 48A - so i don't see any reason why the car couldn't request 32A instead of just 30A. It would just be up to the owner to buy a charger that could put out the extra 2A, wouldn't it?

And to run it though a pair of breakers that would not trip on the load. Two @ 20A?

 

[SeanNelson]

I'm no EE either, but the Wikipedia article on the CCS standard says that in addition to a 50% duty cycle requesting 30A it also states that the duty cycle is variable, in small increments between 0.6A and 48A - so i don't see any reason why the car couldn't request 32A instead of just 30A. It would just be up to the owner to buy a charger that could put out the extra 2A, wouldn't it?

And to run it though a pair of breakers that would not trip on the load. Two @ 20A?

Well, again bearing in mind that I know only enough to be dangerous, I believe you'd need a 40A breaker on each of the two 120V halves of the 240V circuit. That's how my electric hot water heater is wired (although it uses two 30A breakers for a 20A appliance).

 

[DucRider]

I'm no EE either, but the Wikipedia article on the CCS standard says that in addition to a 50% duty cycle requesting 30A it also states that the duty cycle is variable, in small increments between 0.6A and 48A - so i don't see any reason why the car couldn't request 32A instead of just 30A. It would just be up to the owner to buy a charger that could put out the extra 2A, wouldn't it?

This^^ (almost = see **** below)
The PWM signal tells the car how much current the EVSE/charging station can provide - or in Clipper Creek terminology "The maximum current for the vehicle".

The signal on the CP (Contact Pilot aka PP or Proximity Pin) is bidirectional and varies in both voltage and duty cycle as part of the negotiation between the vehicle and EVSE.
The EVSE generates the square wave signal to tell the vehicle how much current (amps) it is allowed to draw.
This is independent of voltage, so in your 50% duty cycle example, the EVSE is indicating 30 amps. If it was connected to 208V, this would be 6.6 kW, at 240V it would be 7.2 kW, at 120V it would be 3.6 kW. This is the upper limit the vehicle is allowed to draw from the EVSE. The vehicle charging circuit controls how much power is actually drawn.

**** Although "charger" is often used instead of EVSE or even "charging station" (and I've mostly given up correcting people), that is technically incorrect. When you are talking about AC charging, the charger is internal to the car. The EVSE is essentially a smart extension cord with redundant safety features. In a technical discussion such as this, I feel it is worth pointing out.

 

[SeanNelson]

This^^ (almost = see **** below)
The PWM signal tells the car how much current the EVSE/charging station can provide - or in Clipper Creek terminology "The maximum current for the vehicle".

Thanks for the clarification. If I understand it correctly, then:

The electrician who installs the EVSE either (a) connects it to a circuit which is sufficient to supply the amount of current that it advertises to the car, or (b) configures it to advertise the amount of current which is available on the circuit to which he connects it.

And then the Bolt, if it can support 32A, will draw that much as long as the EVSE advertises that capability or more. So the question of how much power is being drawn then becomes whether or not the EVSE is providing 208, 220 or 240V. If its 240V then the power would be a little shy of 7.7KW.

 

[DucRider]

[....
The electrician who installs the EVSE either (a) connects it to a circuit which is sufficient to supply the amount of current that it advertises to the car, or (b) configures it to advertise the amount of current which is available on the circuit to which he connects it.

And then the Bolt, if it can support 32A, will draw that much as long as the EVSE advertises that capability or more. So the question of how much power is being drawn then becomes whether or not the EVSE is providing 208, 220 or 240V. If its 240V then the power would be a little shy of 7.7KW.

Re: Installing the EVSE. Installation procedures will vary by manufacturer and model. Some are "variable" and can be configured to work on lower capacity circuits (Not 100% sure, but believe this feature prevents them from being UL listed). Most require a circuit suitable to the rated capacity - a 32A (or even 30A) unit will require a 40A circuit. An EVSE is considered a "continuous duty" device and as such the circuit must be derated by 20% - ie 40A *.8=32A.

So yes, the EVSE "advertises" how much power it can provide. The current the Bolt (or any vehicle) draws is controlled by the on board charging, The actual amount is dependent on many factors such as SOC (State of Charge), pack and ambient temperature, etc.

 

[oilerlord]

I'm just skeptical.....

My two Elantras, bad-mouthed for poor mpg, have given 43 & 45+mpg. My Bolt range will probably hover beyond 250-260miles. I'm skeptical your normal EPA Bolt range will be like-wise.

Hey, if you're able to squeeze 260+ miles out of your Bolt - fill your boots but let's be honest...your Elantra alone (with it's 32MPG combined rating) isn't giving 45+ mpg...your driving-for-efficiency (hypermiling) techniques are making it possible. The majority of Elantra owners are getting the mpg that the EPA says they will:

http://www.fuelly.com/car/hyundai/elantra

My B250e is EPA rated at 87 miles range, and yes, I can squeeze 110+ miles out of the car if I drive like grandpa. Joe Public doesn't drive like that. I'd like to see GM underpromise and overdeliver on range based on "normal" driving habits.

 

[roundpeg]

I'd like to see GM underpromise and overdeliver on range based on "normal" driving habits.

The methodology for mileage calculations is dictated by the EPA, so a manufacturer cannot either under-promise or over-deliver. The differences in real-world results are going to be a function of individual factors, including the mix of driving and technique.

 

[oilerlord]

I'd like to see GM underpromise and overdeliver on range based on "normal" driving habits.

The methodology for mileage calculations is dictated by the EPA, so a manufacturer cannot either under-promise or over-deliver. The differences in real-world results are going to be a function of individual factors, including the mix of driving and technique.

The Leaf's range is EPA rated at 73 miles. Initial Nissan marketing hyped "up to 100 miles" of range. While they didn't lie to customers, they weren't realistic either, which spawned hundreds of "what's wrong with my Leaf's range?" posts. I'm just hoping GM keeps it real to avoid that kind of backlash.

 

[WetEV]

I'd like to see GM underpromise and overdeliver on range based on "normal" driving habits.

The methodology for mileage calculations is dictated by the EPA, so a manufacturer cannot either under-promise or over-deliver. The differences in real-world results are going to be a function of individual factors, including the mix of driving and technique.

The Leaf's range is EPA rated at 73 miles. Initial Nissan marketing hyped "up to 100 miles" of range. While they didn't lie to customers, they weren't realistic either, which spawned hundreds of "what's wrong with my Leaf's range?" posts. I'm just hoping GM keeps it real to avoid that kind of backlash.

Don't forget you don't want to use 100% of the available capacity.

 

[DucRider]

Don't forget you don't want to use 100% of the available capacity.

Why?
I do with no compunctions whatsoever. Granted not on a regular basis, but when needed I don't hesitate at all. I've experienced as near 0% range loss in my Fit EV as can be measured (no Fit EV owner has reported any range loss, even at 50K+ on the clock). We run it to near zero when needed, top it off every night (it starts virtually every day with 100% SOC) and do lots of what conventional "wisdom" shudders at. Modern technologies anticipate and allow for just such behavior, and that's what's needed for a true mass market EV. The user manuals advise to do exactly what I do. The Spark EV wants to be plugged in whenever possible, and I expect the same recommendation on the Bolt.

Earlier EV's, conversions in particular, needed to be babied quite a bit more. The LEAF falls in that category (earlier iterations more so than the new generation). As much as you dismiss active thermal management as unnecessary, it DOES make a difference even in moderate climates. It is not unusual at all to hear the cooling fans kick in when L2 charging my Fit EV in our garage. I'm in Portland so not that different of a climate.

As much as the LEAF did to further the adoption of EV's, some of the choices that Nissan made have actually helped hold back the adoption of EV's. When owners such as yourself talk about the "rules" on how they can use/charge/drive their EV, it turns potential owners off. Yes, I concede that the things you advocate may increase battery longevity in all EV's, most will not be nearly as impacted by violating those "rules" as the LEAF is.

 

[NeilBlanchard]

If the EPA combined number is 238 - it is what it is. I'm just skeptical on how a 3600 lb car with a 0.32 drag coefficient and a 60kWh battery gets there in real-world conditions.

240+ miles was the worst of 4 different drivers. None of them hypermiled, they all used some A/C, and they all drove some of the time 70-75+ MPH.

They have improved the efficiency of the motor and gearbox. They are using about 97% of the battery pack capacity. A Cd of 0.32 is not as bad as you think - the Leaf has been measured to have the same Cd. And the Honda Fit EV has a very similar shape and size, and it goes 82 miles on 20kWh.

 

[NeilBlanchard]

I'd like to see GM underpromise and overdeliver on range based on "normal" driving habits.

The methodology for mileage calculations is dictated by the EPA, so a manufacturer cannot either under-promise or over-deliver. The differences in real-world results are going to be a function of individual factors, including the mix of driving and technique.

The Leaf's range is EPA rated at 73 miles. Initial Nissan marketing hyped "up to 100 miles" of range. While they didn't lie to customers, they weren't realistic either, which spawned hundreds of "what's wrong with my Leaf's range?" posts. I'm just hoping GM keeps it real to avoid that kind of backlash.

No, the 24kWh Leaf has a EPA range of 84 miles, and the 30kWh version is 107.

 

[DucRider]

No, the 24kWh Leaf has a EPA range of 84 miles, and the 30kWh version is 107.

That is the current rating.
The 2011/12 LEAF had an EPA rating of 73 miles on 100% of the pack.
In 2013, EPA test procedures were changed. Part of that change also dictated that the default 80% charge level be averaged with a 100% charge (the owner had to manually select a higher charge level if they were anticipating the need for more range). 80% range was 66, 100% was 84. This netted a 75 mile range rating.
For the 2014 (and beyond) Nissan dropped the 80% charge default and the EPA range reflects the entire (usable) battery capacity.

 

[oilerlord]

If you owned the car, you may be more concerned about the long term health of the battery. If I was leasing, I would care about it either. That said, thermal and other battery management measures have dramatically increased the longevity of main traction batteries. These advances are necessary because (most) people just want to plug in and go...and not be bothered to what may or may not be good for the battery.

Chevy had a huge buffer on the original Volt...and if memory serves they were only using ~11kWh out of a total capacity of 17kWh. With the Spark EV, GM reduced the size of the battery by 2kWh (from 21kWh to 19kWh) but curiously; the car has the same range. With the new Volt...GM's marketing dept says "our customers wanted more range, so we gave them more range". GM increased the battery capacity by just over 1kWh however range increased from 38 miles in the Gen 1 Volt to 53 miles with the Gen 2. I'm guessing that GM is using a much smaller buffer that may have sacrificed long term battery longevity in favor of increased range.

It isn't uncommon to see Gen 1 Volts with 150,000 miles on them, and owners reporting no loss in electric-only range. I wonder if the same will hold true with the Volt 2.0 and Bolt 1.0 - especially given people won't give a thought to what's good for the battery and what isn't.

 

[DucRider]

Battery degradation and range reduction are inevitable - it's matter of degree. ICE vehicles also suffer range reduction. As the engine/drivetrain wears and becomes less efficient, the range available also drops.

Only time will tell on the Bolt, but I believe that we will never see another EV with battery degradation anywhere near the levels seen on the first (and probably current) gen LEAF. You might preserve 5-10 (just a guess) more miles of range in 100K miles by carefully controlling charge levels. On an 80 mile EV, that's big. 228 vs 238 is not such a big deal and most will not want to bother.

 

[WetEV]

Don't forget you don't want to use 100% of the available capacity.

Why?

Sanity. Mine is in short supply. I don't know about yours.

Safety.

Avoiding the bother of running out of charge 100 meters from the house.