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Discussion Starter · #1 ·
Went on a little trip through the Columbia River Gorge with my recently updated 'final' software, 2019 LT.

Plugged in at Electrify America (Gorge Outlets, Troutdale). With EngineLink showing battery Temp of 30C (I assume the sweet spot?). Battery Coolant temp 25C. Battery Coolant pump running at 4296 RPM. Bat. Coolant temp lowered to 18C.

SOC Raw was 44%, power slowly ramped up to 50kW. At 50% SOC, power delivery started going down. By 60% SOC, 32 kW, by 70% 23 kW. At 70% SOC, battery temp was up to 33C. Stopped charge at 70%.

Not impressed to say the least. Anyone have ideas on what the problem might be?

Definitely have 'charger envy' after watching Youtube Byorn Nyland plug in Model 3 SR+ which started charging at 140kW. Pretty much same battery capacity. So, Chevy/Generous Motors, why?
 

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Definitely have 'charger envy' after watching Youtube Byorn Nyland plug in Model 3 SR+ which started charging at 140kW. Pretty much same battery capacity. So, Chevy/Generous Motors, why?
I assume this was your first DC fast charge? The Tesla Model 3 is $10K more than the Bolt, and sells an order of magnitude more. Wonder why? ;)
 

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Yeah, a decade or more of doing nothing but building electric vehicles is bound to get you ahead of the curve. It's still a valid question though: the Bolt is probably THE slowest charging mainstream EV built today. It is what it is. Back in 2016, it was OK because the charging infrastructure couldn't do any more than 50 kW. I am just disappointed that the 2022 didn't increase the charging speed. It seemed like a great opportunity (time) to do that. They'd really need to double the charging speed to make it competitive with the rest of the 2022 EV lineup.

Mike
 

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Wonder if BMS update would allow us to charge at 2C.

 

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This constant demand for punishing a lithium battery with massive 2c -3c charging speeds. Sure it can be done, GM could allow 150kw charging speeds and then deal with the much faster degradation that it ALWAYS entails. The Bolt battery coolant design just isn’t capable of providing the consistent, even, cooling across the 288 cells that’s required to cram 150kw into a 66kwh battery. It was designed to be adequate for moderately fast charging and keep degradation in check. Get used to it.
 

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This constant demand for punishing a lithium battery with massive 2c -3c charging speeds. Sure it can be done, GM could allow 150kw charging speeds and then deal with the much faster degradation that it ALWAYS entails. The Bolt battery coolant design just isn’t capable of providing the consistent, even, cooling across the 288 cells that’s required to cram 150kw into a 66kwh battery. It was designed to be adequate for moderately fast charging and keep degradation in check. Get used to it.
NO.

Dealt with the slow DCFC rate for my entire ownership without complaint, advocating the ability of the Bolt to make road trips with proper planning. I had planned on upgrading to the latest and greatest Bolt when the next generation came out in 2021 (delayed to 2022 by C-19) only to be given the big middle finger by GM with a continuation of the pathetic charging speed. Model Y Long Range is on order now instead of a second generation Bolt. We are keeping the Bolt as a local driving only car. Part of the reason for keeping the Bolt is that my wife is attached to the Bolt, but the logical reason is that the trade in value is crap compared to the real world value as a commuter car for my wife that will last the next 20 years with virtually zero maintenance and low operating cost. We had considered selling the Bolt and getting a Spark EV... but best case we could get 15K for the Bolt and a used Spark goes for 12K now, so trading down to a car with less than half the battery capacity made zero sense when the price difference is so small.

Keith
 

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Discussion Starter · #11 ·
So to hopefully put this thread to bed...
1. No, not my first DC charging experience, but it was the first with the 'final fix'.
2. I did not note that the outside air temp was about 75F
3. The battery temp being 30C was right in the best spot for DC charging as far as I know.
4. It is what it is and I was overly optimistic about getting a faster DC charge rate with the update. At the end of the day, I only paid $21K for a new car. There is that part.
5. Good thing the charging network is constantly expanding. I will try to keep multiple charging stop trip distances below ~120 miles to make stops not tooooooo long.
6. And yes, I still have DC charging speed envy for all of the other EV's. Except for the latest Ioniq maybe.
Thanks for the input.
 

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4. It is what it is and I was overly optimistic about getting a faster DC charge rate with the update.
The Bolt's charge limit is a function of its hardware. Thinking that a software fix will change a hardware limitation isn't optimism, it's a lack of understanding.
 

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Discussion Starter · #14 ·
"it's a lack of understanding".
Ok, then don't hold back. What is the hardware limitation?
 

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There's been some discussion / criticism of the battery cooling system on the Bolt. Although it is a liquid cooling system and superior to the air cooled battery pack of the Nissan Leaf, it is still limited. That may be the reason GM has limited the fast charging rate in the Bolt.
Don't forget in 2017, the first >50kW CCS DCFC EVSEs began appearing. Bolt was engineered and released when 50kW DCFC was 'state of the art'.

I believe the TBMS, and 150A circuits are the limiting factors. The C rate of the Bolt battery chemistry is also probably a factor. Lastly, GM is using Bolt to learn EV technology, they chose (wisely perhaps) to not push the envelope. Comments about Hyundai's Kona\LG issues suggest Hyundai chose to not follow LG's BMS recommendations, I suspect that might mean their push for 75kW DCFC to 'one up' GM on specs might have been a contributing factor to their battery fire issues. If so, perhaps GM's conservative approach has been a lifesaver?

Bolt was targeted as an affordable, 200mi+ EV. It is adequate for longer trips, but not top of class by any means.

GM won't invest much more on the Bolt until Ultium production exceeds demand for premium EV models. By then R&D costs will be mostly paid off by high margin Hummers, Lyrics, Silverados, and Honda\Acuras. It will make sense economically at that point to consider dropping Ultium into Bolts, and thus enabling faster charging at affordable pricing.
 

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Once Ultium becomes available for 2023 model year, I would think GM would adapt the Bolt or replace it with a different model. Ultium battery is significantly cheaper than the Bolt packs. Probably a few thousanf dollars difference to GM per car.
 

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Once Ultium becomes available for 2023 model year, I would think GM would adapt the Bolt or replace it with a different model. Ultium battery is significantly cheaper than the Bolt packs. Probably a few thousanf dollars difference to GM per car.
I suspect Bolt won't get Ultium 1 until Ultium 2 rolls out (2025 or 2026?). I think their strategy will be N-1 for the economy segment, and latest tech for the premium models.

Their initial Ultium production will go towards higher margin Hummer, Lyriq, Silverado, and Honda\Acura. If they find a surplus, they may consider other models, but eventually they will retire BEV2 production and retool the BEV2 plants to produce Ultium cells, perhaps for the N-1 vintage. Their plants currently planned or being constructed probably won't have capacity for Bolt too. I would like to be proven wrong, but that is my guess.

Honda is likely developing their own platform, so the Ultium agreement may be short term to get their foot in the door. If so, surplus capacity would exist a few years down the road unless demand for premium models takes off like a rocket.
 

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Our Bolt will be our everyday car until we stop driving. A 200+ mile range Tesla will be our travel vehicle, perhaps in 2025.
Similar. The Bolt is for everything up to 200ish miles. Our midsize ICE suv gets the rest (425 mi range and refill in <10 minutes. Tesla MY w/new battery chemistry coming, and the Lyriq w/Ultium look promising. I can wait.
 
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