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TonyWilliams
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Mon Feb 12, 2018 12:26 pm

Folks get confused when their consumer device tells them 67KWh was pumped into the battery from empty.

That includes losses in charging, typically about 87% in the Bolt EV at 6-7kW charge rate.

If you multiply 87% times 67KWh, you get the available energy.

GRA
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Tue Feb 13, 2018 4:39 pm

Mostly OT post follows.


GetOffYourGas wrote:
GRA wrote:Like many Californians my age I've been interested/involved in environmental issues since the Santa Barbara blowout in 1969, and energy security since Desert Shield, which was when I got seriously involved in designing and selling off-grid (PV/Wind/microhydro) systems. If I weren't interested in environmental or energy security issues, do you think I'd have done that or be:

Living in a small (ca. 325 sq. ft.) downtown studio within walking distance of my routine errands and do my local travel by bicycle and regional by electrified mass transit, or years ago decided to put off taking any more out of state road trips or flying anywhere until I can do so in a ZEV or at least using sustainably produced biofuels, instead of:

living in a large multi-bedroom house filled with lots of energy-sucking appliances and crap I don't need, having kids and driving everywhere, and flying frequently?

No, Guy. I'm talking about your interest in an EV. At least I assume you are interested, since you are very active on this forum.

Of course I'm interested.

GetOffYourGas wrote: All of your lifestyle choices are to be commended. I *try* to a degree, but nothing like you have done, and I applaud you for it.

No, I was talking about EVs. That they meet your transportation *requirements* is a given. That they meet them as well as your ICEV does and do so at a lower cost (purchase and fuel/maintenance) is where the rest of your argument breaks down.

They don't have to meet them at a lower cost, just a comparable one, if they are to replace ICEs for the general public (and me). Personally, I'd be perfectly happy to give up car ownership entirely, and the day that I have access to a long range ZEV from a mobility service will be the day I seriously start considering doing just that. Thankfully the millennials are less enamored of car ownership than preceding generations, and assuming that trend continues, then EVs combined with AVs will radically reduce the size of the fleet, if not the number of vehicles built or miles traveled.

GetOffYourGas wrote:You want an EV for cheaper transportation, and that's all. You don't want to sacrifice anything in the process. Not that there's anything wrong with that - plenty of people feel that way. And when the EVs get to that point, we will see a huge spike in adoption.

No, I want an EV for ZEV transportation at comparable cost, although lower would be great. But if ZEVs don't provide comparable capability at a comparable(or lower) price, then absent government mandates or a major spike in the price of oil the general public simply won't switch. Here's about the capability we need, but at a price most people can afford:
Life with Tesla Model S: coast to coast in a new 100D (and how it differed from my old 85)
https://www.greencarreports.com/news/1115257_life-with-tesla-model-s-coast-to-coast-in-a-new-100d-and-how-it-differed-from-my-old-85

GetOffYourGas wrote:As for seeing having children as an "undue" stress on the environment, let's just say that we don't see eye-to-eye there. I'm glad that your parents didn't feel that way, too.

If they had I wouldn't be around to care, and you wouldn't care either, but thanks for the thought :D They did limit themselves to me, though, although for other reasons. But it's not children per se that I'm worried about, it's the number of human beings, as we are the major source of environmental stress.

Around 1804 the world's population first reached 1 billion; 2b in 1927 (123 years); 3b in 1960 (33 years, and close enough to my birth year to serve as a base case); 4b in 1974 (14 years), 5b in 1987 (13 years); 6b in 1999 (12 years); 7b in 10/2011 or 3/2012 (13 years), and as of last Dec. was estimated to be 7.6b, or an 153.33+% increase in my lifetime. The rate of growth is finally slowing, but even so most projections for 2050 (which I have a reasonable chance of living to see) are in the 9 to 10.6b range before the population (hopefully) stabilizes and then starts decreasing.

In my own case, most of one side of my family are Catholic, so my decision not to have kids only partially compensates for their fecundity.
Last edited by GRA on Sat Feb 17, 2018 4:07 pm, edited 1 time in total.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

JejuSoul
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Wed Feb 14, 2018 4:53 am

-
It is a shame we no longer have lab tested battery data from the AVTA.

This is the sticker seen on the Bolt EV battery from the YouTube video
Image

But I have driven the Bolt EV. And this is what I saw after driving 470.6km.

Image

Image

Image

LeftieBiker
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Wed Feb 14, 2018 1:55 pm

There is capacity reserved to protect the pack, so 60kwh sounds about right.
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GRA
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Sat Feb 17, 2018 3:48 pm

Edmunds has had a Bolt Premier in their long-term test fleet for about a year now, and all in all they're quite impressed with it as an urban car (which is what it was designed for, after all). They haven't taken it on any long trips, but they've twice gotten over 300 miles (322 and 334) on a charge, both times in L.A. freeway commute traffic (15-50 mph) while using 'L' mode: https://www.edmunds.com/chevrolet/bolt-ev/2017/long-term-road-test/
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

arnis
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Sat Feb 17, 2018 5:33 pm

JejuSoul wrote:-

But I have driven the Bolt EV. And this is what I saw after driving 470.6km.



1) EV's usually don't have precise way to measure energy taken from the battery. +/-5% error is reasonable.
2) It's possible that regen isn't counted. If you reset "used energy" counter to zero, regen downhill
and don't see negative numbers, it means energy recuperated from regen can be used "again".
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

JejuSoul
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Sun Feb 18, 2018 9:34 pm

-
The 57kWh sticker comes from a version 2 battery pack. In the video he mentions that version 2 has different coollant connectors, but maybe there are other differences too.

https://www.youtube.com/watch?v=N3G8JGsEjPA

The version 1 packs are no longer sold. Version 2 costs $12,740.00 see - GM Parts - Electric Propulsion System/Battery for 2017 Chevrolet Bolt EV

There was discussion of a battery recall / replacement on early production Bolt EVs. Perhaps the second version of the battery pack is the fix for this? see UPDATE: Early Chevrolet Bolt Owners Being Notified By GM For Potential Battery Failure

GRA
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Tue Feb 20, 2018 4:52 pm

At 57kWh, that would work out to $223/kWh. Assuming that's actually usable kWh capacity it would be less.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

JejuSoul
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Joined: Sun Jul 03, 2016 6:54 am
Delivery Date: 03 Jul 2016
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Fri Feb 23, 2018 4:23 am

-
Two interesting videos showing the disassembly of the B olt EV battery pack by Professor John D. Kelly at Weber State University (WSU).

https://www.youtube.com/watch?v=N3G8JGsEjPA

https://www.youtube.com/watch?v=ssU2mjiNi_Q

This is the sticker seen on the B olt EV battery from the first YouTube video above
Image

In the second YouTube video above we see that the B olt's pack is made up of eight 5.94 kWh modules and two 4.75 kWh modules for a total capacity of 57.02 kWh. Presumably that means eight modules with ten cells and two modules with eight. Each of the 96 cells would have a capacity of 594Wh. We don't know if that number is total capacity or the usable capacity or even perhaps a nominal rating.

There has also been discussion on this at the T esla site
Chevy Bolt - 200 mile range for $30k base price (after incentive)

Previously on this thread - Comparing the Soul EV battery with the Ioniq EV I had noted -
1/ The 2017 B olt battery pack is 60 kWh and weighs 435kg -> Gravimetric Energy Density = 138 Wh/kg
2/ The I oniq EV battery pack is 31 kWh and weighs 271.8kg -> Gravimetric Energy Density = 114 Wh/kg

I have now realised why GM for the B olt has chosen a more energy dense battery cell than Hyundai. (or GM for the V olt)
From a comment by Jeff N on the T esla Forum
Jeff N wrote: ...it’s more about cell construction than cell chemistry. They optimized the thickness of the cathode, anode, and conductive copper and aluminum collector foils in the Bolt cells to get the highest energy density whereas in the Volt they aimed to enable higher power capability.
The cell specifications, such as we know them from unofficial sources, are quite different. The Bolt cells may be max 2C continuous discharge with a 10 second peak discharge rate of 3.5C whereas the Volt cells may have been rated for 10C continuous discharge. In return for that lower design power, Bolt cells appear to be quite a bit more energy dense.

The cell chemistry in the B olt means the fast charging will be slower and taper earlier. But it has higher energy density = a bigger battery in the same space.

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RegGuheert
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Re: Chevrolet Bolt - 60 kWh, 238 mi, < 7s 0-60

Mon Mar 05, 2018 2:24 pm

RegGuheert
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10K miles: Apr 14, 2013, 20K miles (55.7Ah): Aug 7, 2014, 30K miles (52.0Ah): Dec 30, 2015, 40K miles (49.8Ah): Feb 8, 2017, 50K miles (47.2Ah): Dec 7, 2017.
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