PrairieLEAF
Well-known member
Nice find! I haven't seen preowned Bolts going for less than $20k around here.
Those sound super fun to drive, too.
Those sound super fun to drive, too.
SageBrush said:I agree - A lightly used Bolt for $16k is a fine purchase. That has a very good chance of providing today's level of functionality for 10 years, so about $130 a month.
The only significant downside to the car as an EV is its 50 kW charging but hopefully OP was aware, and is OK with that limit.
Bolt maxes out at 55 kW, not 50... but yeah, not so fast. I've used the exact unit at the location https://electricrevs.com/2018/07/17/watch-a-bolt-ev-at-a-chargepoint-express-250-charge-at-up-to-55-kw/ was filmed out and hit 54 to 55 kW. It was providing free juice for awhile but now they charge $.EVornottoEV said:SageBrush said:I agree - A lightly used Bolt for $16k is a fine purchase. That has a very good chance of providing today's level of functionality for 10 years, so about $130 a month.
The only significant downside to the car as an EV is its 50 kW charging but hopefully OP was aware, and is OK with that limit.
Yeah the fast charge isn’t so fast but I rarely will use it.
What is the ~ average kW for a 20% -> 70% SoC DC charge on a not cold day ?cwerdna said:And, if the battery's too cold, you'll get bitten by slowness too.
buttuh said:I recently found a 2017 Leaf with 8 bars for cheap. Do you guys think it would be worth while to buy the car and have the battery replaced? Will it be replaced with another 30 kWh battery or the 40 kWh battery? Thanks.
Yep. https://www.chevybolt.org/threads/best-charging-curve-ive-seen-yet-from-a-100kw-dcfc.32809/ has more details on Bolt's taper curve on a high enough powered DC FC w/battery temp readings.SageBrush said:What is the ~ average kW for a 20% -> 70% SoC DC charge on a not cold day ?jcwerdna said:And, if the battery's too cold, you'll get bitten by slowness too.
Edit -- never mind, I found a taper curve
No kidding. It also strikes me as a very timid curve for a car with a liquid cooled battery.cwerdna said:Many folks have been pleading for GM to not ship future vehicles w/such slow DC FCing.
I don't know the reason but I've heard the claims for the reason why Bolt's DC FC max rate is currently so slow is electrodes are too thick (example, search https://www.torquenews.com/8861/2020-chevy-bolt-ev-blackjack-or-bust for thick).SageBrush said:No kidding. It also strikes me as a very timid curve for a car with a liquid cooled battery.cwerdna said:Many folks have been pleading for GM to not ship future vehicles w/such slow DC FCing.
I read this morning that the upcoming, new Gen "2021" Bolts to be released in a few months are expected to charge up to 200 kW. Call me skeptical, but 100 kW sustained up to 70% SoC would be most welcome and would do wonders for the car's utility and value.
The U.S. Department of Energy (DOE) has a goal of reducing the production cost of a BEV battery to ultimately $80/kWh, increase the range of EVs to 300 miles, and decrease charge time to 15 minutes or less. In order to achieve this goal, a major effort within the battery research community has focused on increasing the energy density of the cell, which refers to the amount of energy stored in a specified weight or volume. Increasing electrode thickness is an effective way of improving the energy density of a cell.
However, thicker electrodes present several barriers to fast charging. As electrode thickness increases, charge times must also increase in order to avoid lithium plating. Lithium plating occurs when the charge rate exceeds the rate the lithium ions can intercalate into the crystal structure of the anode, which causes metallic lithium to form on the surface. Lithium plating can negatively affect performance of the electrode and lead to accelerated degradation of the battery, as well as impact cell safety. Therefore, it is thought that thinner electrodes are better suited for XFC applications, but this occurs with a tradeoff in increased battery cost. The analysis conducted in this report indicates that fast charge nearly doubles cell cost from $103/kWh to $196/kWh. The increase in cell cost is largely based on decreasing the anode thickness. Using thinner electrodes requires more cells to achieve the same energy density. Managing the heat generated in the battery during a charging event is also a potential barrier to XFC because temperatures in excess of 45°C will rapidly degrade battery lifetime.Higher temperatures can also introduce safety concerns as materials contained within the battery can begin to chemically and mechanically degrade.
The Bolt uses LG cells, which are also used in other EVs that do not have such slow DC fast charging. You might also look up the LG energy density.cwerdna said:I don't know the reason but I've heard the claims for the reason why Bolt's DC FC max rate is currently so slow is electrodes are too thick
Are they the same cells? I've never tracked them. Which other EVs w/LG Chem cells have faster DC fast charging? When did they 1st ship? I suspect they shipped well after engineering work was complete on the Bolt.SageBrush said:The Bolt uses LG cells, which are also used in other EVs that do not have such slow DC fast charging. You might also look up the LG energy density.cwerdna said:I don't know the reason but I've heard the claims for the reason why Bolt's DC FC max rate is currently so slow is electrodes are too thick
Audi, for onecwerdna said:Which other EVs w/LG Chem cells have faster DC fast charging?
Ok. e-tron BEV looks like it didn't ship until March 2019. The A3 e-tron (now dead) was a PHEV that couldn't be DC FCed.SageBrush said:Audi, for onecwerdna said:Which other EVs w/LG Chem cells have faster DC fast charging?
LG says oncwerdna said:Ok. e-tron BEV looks like it didn't ship until March 2019. The A3 e-tron (now dead) was a PHEV that couldn't be DC FCed.SageBrush said:Audi, for onecwerdna said:Which other EVs w/LG Chem cells have faster DC fast charging?
Bolt 1st shipped in Dec 2016: https://media.chevrolet.com/media/us/en/chevrolet/home.detail.html/content/Pages/news/us/en/2016/dec/1213-boltev.html, so I'd guess major engineering work had to be completed at least a year before that.
Funny enough now that you mention the time, it took Jeff at https://electricrevs.com/2018/07/17/watch-a-bolt-ev-at-a-chargepoint-express-250-charge-at-up-to-55-kw/ 60 minutes to get from 12% to 80%,The cooperation was formally announced more than four years ago, in August 2011, by GM's then-CEO Dan Akerson and Juno Cho, president and chief operating officer of LG Corp.
On the reasons for the Bolt EV's fast-charging limitations, however, Piper did provide a little more insider knowledge, stating:
"When we first introduced the Bolt EV back in 2016, our goal was to build the first affordable, long-range electric vehicle. At the time, we optimized the system components around the battery, e.g. cables, contactors, and so on.
"Higher current requires bigger, more expensive cables, etc. and ultimately you reach a point of diminishing returns in terms of saving 10-15 minutes during the occasional DC Fast Charging session versus needing to pay for a more expensive battery system."
In essence, he's saying that GM batteries were more expensive at the time and GM had to keep costs down.
This doesn't preclude the idea that the engineers could optimize the battery management to get closer to a 1C rate on the 2020 model, which would put the maximum rate closer to 65 kW, but the company clearly doesn't see improved fast charging as a primary concern at this point in time. Note the "occasional" and "diminishing returns" terminology when discussing time savings, for example.
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