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Hmmm. I want to know more about how the battery temp controller works. I assumed it has a (probably wide) range from low to high allowed operating temp, and perhaps a wider range for storage temp (i.e. freeze protection).

Has anyone found out what these temps are, e.g. from OBD2?? or GM engineering?

I would think that the 'operating temp low limit' would be sufficient for full speed DC charging and HP performance. I would also think that even a few minutes of 25 kW charging would bring it up to temp...

Your experience indicates otherwise. Thanks for the report.
 

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great blog post, interesting reading.
I traveled from upstate NY to western PA with the Bolt over Thanksgiving. Not one DC fast charger anywhere near my route. It is a very humbling experience pulling into your destination with 16 miles remaining, plugging into level 2 at the hotel, and understanding that you are currently charging at one of only two level 2 charge stations within an hours drive.
 

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Yes, for the sake of your marriage, you should only go on adventures to find the limits of the Bolt's technology by yourself! :laugh: Seriously, (In my Obi-Wan voice) Use the Volt Bro...

I am puzzled by your last energy use screen. Why was there zero use of energy for battery conditioning? I would have expected that piece of the pie to be there.
 

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Yes, for the sake of your marriage, you should only go on adventures to find the limits of the Bolt's technology by yourself! :laugh: Seriously, (In my Obi-Wan voice) Use the Volt Bro...

I am puzzled by your last energy use screen. Why was there zero use of energy for battery conditioning? I would have expected that piece of the pie to be there.
i'm guessing battery conditioning only cools the battery, not heats it.
 

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i'm guessing battery conditioning only cools the battery, not heats it.
Nope it heats it too, empirically determined to be when the pack temp cools to below freezing. Not sure exactly the conditions but when mine was parked in 28 deg temps overnight and was plugged in it warmed the pack
 

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Nope it heats it too, empirically determined to be when the pack temp cools to below freezing. Not sure exactly the conditions but when mine was parked in 28 deg temps overnight and was plugged in it warmed the pack
I am guessing 2.5 hours sitting in the parking lot wasn't enough to drop the pack temperature to the conditioning temperature. I got the impression from bro1999's "Despite having the heat on for the whole hour driving to York, the HV battery was obviously still too cold to allow for maximum charging rates!", that he may be confused about battery heating vs cabin heating?
 

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I am guessing 2.5 hours sitting in the parking lot wasn't enough to drop the pack temperature to the conditioning temperature. I got the impression from bro1999's "Despite having the heat on for the whole hour driving to York, the HV battery was obviously still too cold to allow for maximum charging rates!", that he may be confused about battery heating vs cabin heating?
I am actually confused by his datapoint. I would have assumed that as soon as he plugged into the DC fast charger that the pack Thermal Management System would have warmed the pack to the ideal temp to accept charge at the fastest rate allowed using wall power if the pack was not already warm enough.
 

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I am actually confused by his datapoint. I would have assumed that as soon as he plugged into the DC fast charger that the pack Thermal Management System would have warmed the pack to the ideal temp to accept charge at using wall power if the pack was not already warm enough.
Yes. That would seem logical. I find it very frustrating that GM, or any OEM for that matter, doesn't offer info like this on a website. The owner's manual could stay dumbed down, but it seems like it would be great for customer loyalty to offer this sort of stuff for those who care.
 

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Discussion Starter #10 (Edited)
I am actually confused by his datapoint. I would have assumed that as soon as he plugged into the DC fast charger that the pack Thermal Management System would have warmed the pack to the ideal temp to accept charge at using wall power if the pack was not already warm enough.
The TMS does turn on when the battery is cold enough when plugged into a fast charging station. Think is the battery heater is only 2-3 kW max (based off what I've observed with TorquePro), so it still takes a while for the battery to heat up even with the heater on and electrons flowing from the charging station. The Bolt won't allow "full pull" fast charging rates until the HV battery temp is in the low 70's.

When I was charging in York for the return leg, the max amps were right around 60A for the first 15 minutes or so, then between the 15-25 minute marks the amperage creeped up into the 70A range and gradually increased until I hit the station's max 100A output after 25 minutes of being plugged in charging.

I thought that having the heat on while driving would warm the battery to some extent, but it seems that isn't the case.
 

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The battery probably has such a low ESR that the extra current draw from cabin heating doesn't overcome the air cooling the bottom plate. Kind of a bummer for cold weather driving. They should offer a evacuated tube solar thermal collector for the roof to supplement the heating functions :) Would work OK until the sun goes down!
 

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The battery probably has such a low ESR that the extra current draw from cabin heating doesn't overcome the air cooling the bottom plate. Kind of a bummer for cold weather driving. They should offer a evacuated tube solar thermal collector for the roof to supplement the heating functions :) Would work OK until the sun goes down!
won't help the battery but to augment cabin heat buy a dark color Bolt, oh, like Black ;-)
 

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A blog post about my experiences taking my Bolt on a road trip to rural PA in the snow, and my unexpected experiences at a CCS fast charging station.

http://bro05.blogspot.com/2017/12/th...you-think.html
Awesome post - thanks - Quick question - what was your high/low/average speed during the trip? I have a similar length trip coming up, but I will be on rural highways (~ 50-56mph), and I want to factor that into my plans.
 

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Think is the battery heater is only 2-3 kW max (based off what I've observed with TorquePro),
I am not doubting what you saw, but I am puzzled that the cabin heater is good for 9 kW max heating only 2 liters of glycol, while the battery heater is only good for 3kW max when attempting to heat 7 liters of glycol, and 900 pounds of batteries.
 

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I am not doubting what you saw, but I am puzzled that the cabin heater is good for 9 kW max heating only 2 liters of glycol, while the battery heater is only good for 3kW max when attempting to heat 7 liters of glycol, and 900 pounds of batteries.
batteries don't complain like passengers if it takes too long to get warm, in addition, the passengers would complain if the heat is set at say 50 F. requirements drive the heater size.

edit: not to mention that the passengers are being indirectly heated through forced convention where the battery is more direct conduction thru glycol loops.
 

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You didn't happen to have TorquePro running while you had this unfortunate charging incident. I would be interested to know what the pack temp was prior to plugging in, and after the charge completed. It’s entirely possible the station was throttled. Did the station report what the charge rate was?
 

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batteries don't complain like passengers if it takes too long to get warm, in addition, the passengers would complain if the heat is set at say 50 F. requirements drive the heater size.

edit: not to mention that the passengers are being indirectly heated through forced convention where the battery is more direct conduction thru glycol loops.
You are right. And I have seen the proof before, but it didn't sink in. Duh!

http://99mpg.com/blog/finally-i-have-an-electric-car-chevy-bolt/keeping-the-batteries-warm-in-winter/
 

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Battery conditioning temperatures

You didn't happen to have TorquePro running while you had this unfortunate charging incident. I would be interested to know what the pack temp was prior to plugging in, and after the charge completed. It’s entirely possible the station was throttled. Did the station report what the charge rate was?
With my LELink OBDII interface, and EngineLink HD, I have made some limited observations this fall. A couple of the graphs are elsewhere on this site already, but I include them here too. With outside temperatures in the 38-48 F range, I found my battery temperature on leaving home from a 54 F garage to be about 59 F. When I returned home after say 60-70 miles the battery temperature was about 54 F. During charging the battery temperature rose from 54 to about 57 F without battery heat. Just as the charging ended, battery heat was turned on by the car, to bring the battery temperature to about 59 F again. The graphs are attached here again; but the conditions are in the other post. You can see the little bump in the charging current near the end of the charge. That is the separate battery heat function drawing current from the charger to heat the batteries. Its about 2-3 kWh. The graphs are of the HV voltage and current, while the charger voltage and current was 240 volts and about 19 amps ac.
 

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Is there a PID for how much current the battery thermal system is pulling? I didn’t see one listed in the Volt PIDs which is the basis for my Bolt PIDs. I have to derive it from other values, and it’s not very accurate.
 

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Battery heater, (conditioning)

Is there a PID for how much current the battery thermal system is pulling? I didn’t see one listed in the Volt PIDs which is the basis for my Bolt PIDs. I have to derive it from other values, and it’s not very accurate.
I use Bat Heat (W). As the HV charger current and voltage is available as a function of time, you can correlate the charger current with the Bat heat (W) as a function of time. Maybe, you could simply read it off the charging current curve, because you can deconvolute the bat heat current from the charging current. If you look at my graph, its clear where the battery heat bump is on the charging curve. I am not sure current is too important, because we tend to think in Watts anyway.
 
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