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DC fast charging our Bolt

14K views 59 replies 17 participants last post by  SpicyBolt  
#1 ·
The Japanese auto industry came up with the CHAdeMO standard in 2009.

The Nissan Leaf, and Mitsubishi i-MiEV, arrived arrived in the US in 2011. The few DC chargers were 120 A, 50 kW maximum.

The US, and European, auto industry came up with the idea for CCS charging standards, CCS1 in North America, and CCS2 in Europe, in 2012.

The first car in the US to have CCS1 was the 2014 Chevy Spark EV. The chargers available then were 50 kW maximum capacity, and had both CHAdeMO, and CCS1 plugs.

The Bolt came out in December of 2016. We took our first road trip in the fall of 2017. All the chargers we used were 50 kW max. Just finding one required driving miles off the highway. It was an amazing adventure, and being able to charge in an hour or so seemed magical. The only other EV we ever saw at a charger was the Leaf.

In 2019 we took road trips using the new 150-350A, 150-350 kW chargers, which allowed charging in 30-45 minutes. That year, I saw a high reading of 56.3 kW for several seconds, charging on an EA unit. I got a screen shot about 30 seconds later.



Then came COVID-19, the battery fire software updates, and finally the battery replacements.

I have DC fast charged the new battery 4 times since getting it installed in September of 2022. The temperatures have not been high enough to get the battery to the 75 -85 F range it requires for 150A, 50-55 kW charging, until yesterday.

I picked the Bolt up from our local Chevy dealer, after having the third brake caliper replacement. Still have one original, properly functioning brake caliper, at 52K miles.

I did some errands. Even though it had been in the 80s F for several hours, the previous night had been in the high 40s F, so the battery was only in the high 60s F.

I drove down the interstate for 45 minutes, doing some accelerating, and regening, when possible, to warm up the battery. I managed to arrive at the Sheetz, to try out the EA DC chargers, with the battery in the low 70s F.



The double CCS 150 kW charger was down. One of the 350 kW chargers was down. I used the other 350 kW charger, leaving the 150 kW CCS/CHAdeMO for anybody else showing up.

The charge started,



and the battery heater started immediately at 2.0 kW, and soon the pack was mid-70s F.



By 25% SoC, the pack was in the upper 70s F, and the heater had tapered to 0.5 kW.



The heater then cut off, and the pump kept circulating the hot coolant, trying to maintain a fairly even temperature from module to module.



By 50% SoC, the circulating hot coolant, and the act of charging, had raised the battery to the high 80s F.



At this point, the AC chiller kicked in to attempt to keep the battery in its happy place, below 90 F.



I quit charging at 52.2% SoC, and the conditioning promptly stopped.




Note that 50 pump rpm is a false reading. It is actually stopped.



The Bolt is fast charging at below 1C under the best of conditions. I saw 51.6 kW max on this charge, and EA reported 52 kW max in their summary. The conditioning struggles to keep the modules within 3 F of each other during charging. This seems pretty sad.

However, I had a $50K, 72.8 kWh, 2023 Subaru Solterra, as a loner, while they were working on the brakes of our Bolt. It averaged just over 2mi/kWh while driving exactly as I drive our Bolt, seeing 4 mi/kWh. I charged it to a preset 80% SoC in our garage overnight, and it was below 75% SoC when I arrived at the EA station, under 10 miles later, to try a 350 kW fast charger. Granted, it was surely tapering by that point, but the maximum EA recorded was 13 kW.
 
#2 ·
In 2019 we took road trips using the new 150-350A, 150-350 kW chargers, which allowed charging in 30-45 minutes. That year, I saw a high reading of 56.3 kW for several seconds, charging on an EA unit. I got a screen shot about 30 seconds later.

View attachment 54337

Then came COVID-19, the battery fire software updates, and finally the battery replacements.

I have DC fast charged the new battery 4 times since getting it installed in September of 2022. The temperatures have not been high enough to get the battery to the 75 -85 F range it requires for 150A, 50-55 kW charging, until yesterday.

I drove down the interstate for 45 minutes, doing some accelerating, and regening, when possible, to warm up the battery. I managed to arrive at the Sheetz, to try out the EA DC chargers, with the battery in the low 70s F.

The charge started, and the battery heater started immediately at 2.0 kW, and soon the pack was mid-70s F.

By 25% SoC, the pack was in the upper 70s F, and the heater had tapered to 0.5 kW.

The heater then cut off, and the pump kept circulating the hot coolant, trying to maintain a fairly even temperature from module to module.

By 50% SoC, the circulating hot coolant, and the act of charging, had raised the battery to the high 80s F.

At this point, the AC chiller kicked in to attempt to keep the battery in its happy place, below 90 F.

I quit charging at 52.2% SoC, and the conditioning promptly stopped.

The Bolt is fast charging at below 1C under the best of conditions. I saw 51.6 kW max on this charge, and EA reported 52 kW max in their summary. The conditioning struggles to keep the modules within 3 F of each other during charging. This seems pretty sad.
Are you saying the new/replacement Battery isn't as good as the Original Battery that came with your 2017 Bolt ... or that the Bolt's DCFC Charge Time is "sad" in general?

Either way ... I appreciate your candor.
 
#6 ·
Are you saying the new/replacement Battery isn't as good as the Original Battery that came with your 2017 Bolt ... or that the Bolt's DCFC Charge Time is "sad" in general?
I don't know if the charging software has changed since we got our Bolt. The only year we did any DC fast charging, when there were chargers that could deliver the 150 amps the Bolt is capable of taking, was 2019, and I have that one example where I paid attention, and took that screen shot. It did not exceed 150 amps then, and the shot shows 147.6 amps, which is about what I have seen since getting the new battery.

I don't think the Bolt charging is "sad". I am just amazed at how much our expectations have increased in the 12 years modern EVs have been available.
 
#10 ·
Oh! One other thing to note. You can see the Bolt request 140+ amps to the battery, when the battery is between 75-85 F, which the charger will deliver. You can also see the charger deliver more amps than the battery is requesting on the other PID, when you have the car on, and the HVAC is running. I have EA charge histories with 67 kW maximums. That is probably 55 kW to the battery, 2 kW to the battery heater, 7.5 kW to the cabin heater, 1.5 kW to the 12 volt charger, and 1 kW to the AC for humidity control.
 
#11 ·
On a small scale - while topping up at a EA while waiting for somebody at the airport - I was getting about 25kw just charging. It was kind of chilly that night, though, so I turned on the heat. Charge rate jumped to 32-33 - normal add (about 6-7kw) for running the heater. No sweat for a 150kw charger and nobody else on it (once I got it going after a call and a reset).
 
#19 ·
Here on Long Island we had only one 1-inch snowfall all winter, and February was the third warmest on record. The local Islip weather station recorded zero inches of snow all winter, that has never happened before.
I’m a cyclist, and I did dozens of rides on perfectly clear roads this past winter, when I’m usually stuck in the house going nowhere on a trainer.
 
#16 ·
Where I live and travel, nearly all the non-Tesla DC chargers are only 50kW anyway, so it’s not like I would really benefit from owning a different brand of vehicle than a Bolt. If I had ignored Elon Musk’s villainy and bought a Tesla, it would have cost nearly $20,000 more and then I’d have to pay 50 cents per kWh for DC fast charging, so there is no financial reason to buy one of those.
 
#23 ·
Hi
Is this an third party app ?
Our car hasn't arrived yet so I'm idling browsing forums gathering information.
Thanks
A former member here did most of the work.


 
#36 ·
^^^
I haven't watched the video but he shows CarPlay a bunch of times and it looks like the My Chevrolet app's CarPlay support.

See Intro to CarPlay and iPhone and Use your vehicle’s built-in controls to control CarPlay. You have the 3 MRU items on the left and a sorta home button in the lower left.

At 9:10, that's Chevy's native UI as part of the infotainment system. Target charge level tab is only on '19+ Bolts. '17 to '18 only had a hilltop reserve toggle.
 
#37 · (Edited)
Did another DC fast charge yesterday. The temperature hit a high of 91 F, and was down to 86 F by 4:42 pm, when I stated charging at the EA 150 kW charger. The DIC SoC was 20.8%. Battery module temps were 80.6 F-86.0 F.



The car requested 150 amps immediately on startup, and the battery coolant pump started circulating unconditioned coolant. As always, the amps into the battery were just under the requested figure.



When the battery modules reached 84.2 F-89.6 F, the AC chiller turned on.



The modules reached a high of 91.4F, as the coolant reached its lowest temperature, 57.2 F.



At the end of charge, the amps were already tapering at 49.4% SoC. Notice the unfiltered temperature reading at the grille is much higher than the long term averaged reading on the dash.



On the way home, the AC chiller, and coolant circulating pump, continued to run. I deliberately had the HVAC off, so as to not confuse cabin cooling with the battery conditioning behavior. With the HVAC off, outside air, and fan only, the cabin was cooled anyway, as the evaporator is in the cabin.



The last screen shot was taken in the garage on arriving home. Notice the battery voltage bumps back up with the car off, and no load. The coolant, although no longer circulating (50 rpm is the default reading at zero rpm), the module temperatures continue to drop, as the coolant temperature rises.



EA said I charged for 21 minutes, and added 18 kWh, an average rate of 50.8 kW. They saw a max from the charger of 53 kW.
 
#39 ·
On the way home, the AC chiller, and coolant circulating pump, continued to run. I deliberately had the HVAC off, so as to not confuse cabin cooling with the battery conditioning behavior. With the HVAC off, outside air, and fan only, the cabin was cooled anyway, as the evaporator is in the cabin.

View attachment 55303
If there's no valve for the cabin refrigerant loop, are you introducing latent heat from the cabin into the battery loop and then your confusion between the cabin and battery conditioning would still exist?
 
#38 ·
Did my first real charge at a EA site today (others were just testing their system). 43->80%, on the way home from the Bay Area. Started at 53kw, ended at 19. Took about 40 minutes. Was talking with a guy at the next charger (who was getting tired of waiting for it to get to 100% - sort of stuck at 98o_O) who had just bought a "used" Lightning supposedly getting a good deal (100 miles on it); made sure he had the list of apps (for my area and his: EA, Chargepoint, EVGo, and of course Plugshare). He had an electrician scheduled to come tomorrow to install a L2 charger. I sort of introduced him gently to the idea that charging to 100% was not needed or desirable...
 
#40 ·
The Japanese auto industry came up with the CHAdeMO standard in 2009.

The Nissan Leaf, and Mitsubishi i-MiEV, arrived arrived in the US in 2011. The few DC chargers were 120 A, 50 kW maximum.

The US, and European, auto industry came up with the idea for CCS charging standards, CCS1 in North America, and CCS2 in Europe, in 2012.

The first car in the US to have CCS1 was the 2014 Chevy Spark EV. The chargers available then were 50 kW maximum capacity, and had both CHAdeMO, and CCS1 plugs.

The Bolt came out in December of 2016. We took our first road trip in the fall of 2017. All the chargers we used were 50 kW max. Just finding one required driving miles off the highway. It was an amazing adventure, and being able to charge in an hour or so seemed magical. The only other EV we ever saw at a charger was the Leaf.

In 2019 we took road trips using the new 150-350A, 150-350 kW chargers, which allowed charging in 30-45 minutes. That year, I saw a high reading of 56.3 kW for several seconds, charging on an EA unit. I got a screen shot about 30 seconds later.

View attachment 54337

Then came COVID-19, the battery fire software updates, and finally the battery replacements.

I have DC fast charged the new battery 4 times since getting it installed in September of 2022. The temperatures have not been high enough to get the battery to the 75 -85 F range it requires for 150A, 50-55 kW charging, until yesterday.

I picked the Bolt up from our local Chevy dealer, after having the third brake caliper replacement. Still have one original, properly functioning brake caliper, at 52K miles.

I did some errands. Even though it had been in the 80s F for several hours, the previous night had been in the high 40s F, so the battery was only in the high 60s F.

I drove down the interstate for 45 minutes, doing some accelerating, and regening, when possible, to warm up the battery. I managed to arrive at the Sheetz, to try out the EA DC chargers, with the battery in the low 70s F.

View attachment 54343

The double CCS 150 kW charger was down. One of the 350 kW chargers was down. I used the other 350 kW charger, leaving the 150 kW CCS/CHAdeMO for anybody else showing up.

The charge started,

View attachment 54345

and the battery heater started immediately at 2.0 kW, and soon the pack was mid-70s F.

View attachment 54346

By 25% SoC, the pack was in the upper 70s F, and the heater had tapered to 0.5 kW.

View attachment 54347

The heater then cut off, and the pump kept circulating the hot coolant, trying to maintain a fairly even temperature from module to module.

View attachment 54348

By 50% SoC, the circulating hot coolant, and the act of charging, had raised the battery to the high 80s F.

View attachment 54349

At this point, the AC chiller kicked in to attempt to keep the battery in its happy place, below 90 F.

View attachment 54350

I quit charging at 52.2% SoC, and the conditioning promptly stopped.

View attachment 54351


Note that 50 pump rpm is a false reading. It is actually stopped.

View attachment 54352

The Bolt is fast charging at below 1C under the best of conditions. I saw 51.6 kW max on this charge, and EA reported 52 kW max in their summary. The conditioning struggles to keep the modules within 3 F of each other during charging. This seems pretty sad.

However, I had a $50K, 72.8 kWh, 2023 Subaru Solterra, as a loner, while they were working on the brakes of our Bolt. It averaged just over 2mi/kWh while driving exactly as I drive our Bolt, seeing 4 mi/kWh. I charged it to a preset 80% SoC in our garage overnight, and it was below 75% SoC when I arrived at the EA station, under 10 miles later, to try a 350 kW fast charger. Granted, it was surely tapering by that point, but the maximum EA recorded was 13 kW.
This is a good thread-starter/post because it puts the Bolt's 'slow' 55kW DCFC in context. IOW, at one point in time not all that long ago, 55kW DCFC was perfectly acceptable.

Of course, time marches on, and now it's considered the Bolt's Achilles Heel relative to the advent of much faster DCFC stations and capability of other, newer BEVs. The silver lining is that any bad publicity the Bolt might receive over this apparent detriment can lower Bolt demand/increase supply/lower the price for the savvy BEV shopper.

As it is, the Bolt is a pretty **** good deal right now with the return of full $7500 federal tax credit eligibility, particularly if DCFC is not all the necessary for the owner's needs.
 
#41 ·
This is a good thread-starter/post because it puts the Bolt's 'slow' 55kW DCFC in context. IOW, at one point in time not all that long ago, 55kW DCFC was perfectly acceptable.

Of course, time marches on, and now it's considered the Bolt's Achilles Heel relative to the advent of much faster DCFC stations and capability of other, newer BEVs. The silver lining is that any bad publicity the Bolt might receive over this apparent detriment can lower Bolt demand/increase supply/lower the price for the savvy BEV shopper.

As it is, the Bolt is a pretty **** good deal right now with the return of full $7500 federal tax credit eligibility, particularly if DCFC is not all the necessary for the owner's needs.
In my travels throughout New Jersey and New York, I don't think I've ever used a DC fast charger that could max out at more than 75 kW or so. For all this talk about 350 kW DC charging, there aren't really all that many dispensers out there that are even available for drivers that exceed 55 kW -- other the the usual Tesla superchargers. So, the 55 kW max for the Bolt isn't really all that big of an issue.
 
#47 ·
@GJETSON Since there was no prior response, I'll provide the conclusion. There's no valve isolating the cabin refrigerant loop from the battery loop in a Bolt. You are introducing latent heat from the cabin into the battery loop and your confusion between the cabin and battery conditioning still exists. This is especially true when the cabin fan is engaged to move cabin-air heat across the evaporator.
 
#50 ·
@usedBolt Agreed. However, drivetrain cooling has nothing to do with the refrigerant loop.

@GJETSON Ah. I now see what you were trying to achieve. However, running the cabin fan also extended the battery conditioning.

I'm still confused by your 2 earlier posts though. Why do you believe that single a valve to isolate the cabin-loop from the battery-loop requires another evaporator (at a minimum) and you also implied that currently there is not already 2 evaporators in the AC loop? A single valve between the existing cabin-loop and battery-loop is all that would be needed. I totally agree with your assessment of GM cost savings though.

As an example, with the OEM design, if the battery is being cooled the cabin will also be cooled. That may not be wanted and adversely, cabin heating may then be needed. In any case, with the cabin in the loop, battery conditioning will be extended. The same can be said for cabin dehumidification in the winter while the battery is being heated.
 
#51 · (Edited)
@usedBolt
Why do you believe that single a valve to isolate the cabin-loop from the battery-loop requires another evaporator (at a minimum)

you also implied that currently there is not already 2 evaporators in the AC loop?
You may be an AC expert. I certainly am not. But google says, "The condenser coil releases heat to the outside air, while the evaporator coil absorbs heat."

It does appear that Tesla has valves to cut the cabin evaporator out of the loop.

 
#52 ·
Sorry for thinking out loud here. I had assumed that the temperature difference, which is necessary for the refrigerant to absorb heat from the battery coolant, required the liquid to vaporize. And that required a space with greater volume. Are the high pressure lines the same size as the low pressure lines? Is the pressure difference just created by the compressor pulling in refrigerant? There is no expansion chamber/evaporator? needed? AC experts?
 
#54 ·
It has a traditional refrigerant-to-air evaporator in the cabin, for the cabin. It also has a chiller, which I have come to understand is a refrigerant-to-coolant evaporator for the battery coolant loop. These two are in series, with no cutout valves. They both run any time the compressor is on, which is a pathetic design, but cheap.