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So, an increasingly common question around here is something like:

"It's 13 degrees outside, is my battery OK?"

With this post, I'm going to try to capture the temperature thresholds where the different modes kick in. This data is NOT official! It's just what I've gathered from reading various sources.

It's important to note up front that we are talking about the temperature of the battery pack here, not ambient temperature. It's a 400 pound battery pack, well insulated, so it is going to take a long time to cool down / warm up to whatever the ambient temp is. An overnight park, even in a mode where the TMS isn't kicking in, is not necessarily long enough to get the pack to ambient. So an overnight low of -13 F doesn't mean the battery pack itself will actually cool down to that cold!

Code:
Volt battery temperature management system (TMS) modes

Avg Cell Temp range | Volt is parked       | Volt is powered off  | Volt is powered on
                    |  and plugged in      |  but NOT plugged in  |  (e.g. being driven)
--------------------|----------------------|----------------------|----------------------
                    |                      |                      |
above 164 F         | passive cooling      |                      | car won't run (HV contactors opened)
                    |                      |                      | until battery is cooled below 164F 
                    |                      |                      |
164 F .. 113 F      | active cooling*      |  No Active TMS       | active cooling(1*)
                    |                      |                      |
 113 F .. 90 F      |active/passive cooling|                      | active/passive cooling(1*)
                    |                      |                      |
 89 F .. 73 F       | no action -- ideal temperature band for long-term life
                    |                      |                      |
 73 F .. 25 F       |                      |                      |
                    |                      |                      |
 25 F .. 14 F       | warming              |                      | warming(2)
                    |                      |                      |
 14 F .. -13/22 F   | warming              |                      | warming(2)
                    |                      |                      |
below -13F          | warming              |                      | vehicle won't move
(2011-12)           |                      |                      |"Battery Too Cold Plug In To Warm" DIC message
below -22F (2013+)  |                      |                      |until plugged in and battery is warmed by 360V                                                                        battery coolant heater(2)



- Notes:-
independent hot ambient temperature TMS data collection by gm-volt member George S. Bowler 
See front page article for more info: http://gm-volt.com/2013/05/03/volt-battery-thermal-management-system-in-the-hot-arizona-sun/

* active cooling = HV A/C compressor ON
(1) At extreme high temps, the ICE may come on to generate power for the TMS to work faster,
  but only if the car is powered on (that is, the ICE won't start by itself, unmanned)
(2) At low temps, the ICE may come on to heat coolant for the cabin heater, but only if the car is powered on (that is, the ICE won't start by itself; it will  only start once the car is powered on or it receives a remote-start command);  the ICE will shut off once
  it reaches 150 F.  Note that the ICE coolant can not be used to directly heat the battery because the
  battery coolant loop is separate.
The above is for regular operation. If you are putting the Volt into storage for an extended period, without plugging it in, the manual says (on page 10-25) that ideally you should store it where the temperature range will be within 14° F .. 86° F. Traction battery SOC should be at 50%, and the 12 volt battery should be disconnected or on a trickle charger. Note that this is for long-term storage, not just parking it for a few days or even weeks.

The data I have in here now is what I gathered from reading back a few pages in this thread, including that digested from Charles Whalen's post here last month, WOT's front page article and comments last Thursday, and whatever further comments I can get.

WOT and others, can you help clarify this further? You can just describe the behavior in plain text, and I'll figure out how to fit it in above (adjusting temperature ranges accordingly). It seems like the low temperature operation is what is most unknown here.
 

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I am getting more confused. So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car? Can I get the electronics to operate to open the windows or do I just have to open the doors lmao? If I can't start the car to get the combustion engine to run for AC then how am I supposed to cool the car down if I am no where near a plug? Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours? Maybe you are saying I can start the car to run the ICE but I have to wait for the car to cool/heat in order to drive???

Thanks
P
 

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So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car?
It's my understanding that the battery is pretty well insulated. I think the way it works is an 8 hour soak isn't enough to bring the battery out of operating temperature range. The battery is probably significantly better insulated than the interior of your car. The car may get really hot as far as you're concerned, not so much for the battery.

Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours?
Same here, but if you're going to leave it out in the cold a *long* time you'd better have a block heater outlet. Just like you would with any other car. An ICE car doesn't do well in that environment either...
 

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The car cannot even start without it coming back within range? ChrisC says it's not drivable but doesn't say you can't star the ice. That is a disappointment if you have to somehow get it plugged in, towed, or wait for the outdoor temperature to come back within range. I can't believe if I have 60% battery left and the batteries are close to going over 120 degrees it wouldn't try and cool down instead of creating a scenario where the car cannot be used at all and also allow the batteries to reach damaging temperatures
 

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I can't believe if I have 60% battery left and the batteries are close to going over 120 degrees it wouldn't try and cool down instead of creating a scenario where the car cannot be used at all and also allow the batteries to reach damaging temperatures
It's my understanding that if you have 60% SOC the battery CAN'T be out of its temp range. WOT (or anyone else who knows) can comment, but I believe it can always start the ICE hot. It's just a deep cold soak with battery < 50% that forces a plug in. And many places where that can happen have provisions for block heaters.
 

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My concern is with the bottom of that scale. According to the manual, there is a minimal temperature below which the Volt will not start at all and needs to be plugged in to start (even the ICE as far as I can understand). It's critical for me to know what that temperature is, otherwise I could be stranded at work at the end of a day.
 

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Indeed, therfman, it's recent concerns from folks like you that inspired me to start trying to make sense of this. We'll get to the bottom of it, pun not intended :)
 

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I am getting more confused. So if i leave my car out on a 100 degree day after depleting the batteries by 50% by getting to work and the inside of the car heats up to 130 degrees what do I do to get the temperature down? Can I even start the car? Can I get the electronics to operate to open the windows or do I just have to open the doors lmao? If I can't start the car to get the combustion engine to run for AC then how am I supposed to cool the car down if I am no where near a plug? Same goes for when it is -20 outside all day. Am I not supposed to drive or let the car sit out during these temperatures for 8 hours? Maybe you are saying I can start the car to run the ICE but I have to wait for the car to cool/heat in order to drive???

Thanks
P
No, no, no. When the Volt's battery is at the temperature extremes, you can still drive the car. However, rather than operating in EV mode (assuming the battery SOC is above the lower threshold), the ICE will come on and run the TMS to cool/heat the battery until the battery temp gets back to spec. Once the battery is back to temp spec, the Volt will revert back to EV mode (assuming the battery SOC is above the lower threshold). You will not be stranded.
 

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Page 5-45 of the Operator's Manual says otherwise:

"BATTERY TOO COLD, PLUG IN TO WARM
This message displays during extremely cold temperatures, when the vehicle will not start until the high voltage battery is warm enough. Plug the vehicle in to allow the charging system to warm the high voltage battery, then the vehicle can be started."

I assume that this problem happens because the high-voltage battery is used to start the ICE, and when the battery is too cold, even starting the ICE could damage it. I think it would have made more sense to use the 12V battery to start the ICE, they have been used in the cold for decades to start cars, and they are cheap to replace when they do die from the cold.

Luc
 

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I looked up the all time record temperatures in California to see what the range would be for My Volt.

Record Low - -45F
Record High - +134F

Annual snow fall at Kirkwood Ski resort about 37 miles from my house - 42ft

Some days I just would not be driving my Volt in these areas
 

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I would add, obvious to most here I'm sure, that the issue with the cold temps is the actual performance of the battery at that time. Cold batteries provide less energy (in simple words), as the MiniE owners can testify to. So it's worth mentioning that there is a reason to condition at the low end, but that reason has nothing to do with long term life (as you described) but rather to do with short term performance.
Even without TMS during unplugged idle time, the Volt will be far better than the MiniE during cold weather. The MiniE did nothing to heat the battery and it would eventually approach the environmental temperature. With heat during charge and good insulation, the Volt battery will hold heat during the idle times and be much warmer than an unmanaged battery.
 

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I'm assuming the Volt doesn't have a 12V starter like a normal car and that one of the two M/Gs actually start the ICE. That would explain why the pack is needed to start the ICE. That said, starting the ICE is much easier on the batteries than driving the car...so it seems like there would almost always be enough power in the batteries to start the ICE. Hmmm..
 

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I've edited the FAQ to point to my post over the weekend about battery temperatures, but I could really use some more information. In particular, I'm most concerned about whether these statements are true:

car won't run until battery is cooled below 122 F by TMS

car won't run until battery is warmed above -13 F by TMS

At extreme temps (high or low), the ICE may come on to generate power for the TMS to work faster, but only if the car is powered on (that is, the ICE won't start by itself, unmanned)
Can anyone say whether they know these to be true? And please note that I'm not saying the Volt won't work below -13F. I am saying that if it sees those extreme battery temps when powered up, it's going to immediately do what it can to warm up the battery before it allows motion. For example, it could be as little as 90 seconds of warmup time, based on Lyle's recent experience.

Please don't report how cold it is in Minnesota right now, we know :)
 

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No, no, no. When the Volt's battery is at the temperature extremes, you can still drive the car. However, rather than operating in EV mode (assuming the battery SOC is above the lower threshold), the ICE will come on and run the TMS to cool/heat the battery until the battery temp gets back to spec. Once the battery is back to temp spec, the Volt will revert back to EV mode (assuming the battery SOC is above the lower threshold). You will not be stranded.
Rooster, what is your source for this statement?

The various posts below from Charles Whelan (who reminds us “Let the perfect not be the enemy of the good”) are excellent.

But, despite what Charles and Rooster say, we are still left with this rather disturbing information from Page 5-45 of the Operator's Manual:
"BATTERY TOO COLD, PLUG IN TO WARM
This message displays during extremely cold temperatures, when the vehicle will not start until the high voltage battery is warm enough. Plug the vehicle in to allow the charging system to warm the high voltage battery, then the vehicle can be started."

I just cannot understand why plugging in is a necessity when you have an ICE.

Here’s my take on the worst case scenario, and it covers both the too hot and too cold to start cases:
My SOC is 45%. The significance of this is that I am below the SOC where the TMS will control the battery temperature while the car is off, according to the posts in this thread. (Need sources for this as well, but for now I'll assume it's correct.)
I start my Volt. The batteries are too hot or too cold to drive away. I do not have access to a plug. The ICE starts. I get a message from the VOLT as follows:
” Please wait. Car will not go due to battery temperature. The engine is now conditioning the battery. Estimated time to departure: n minutes”
Of course, “n” would change in real time.

Lyle, I’d like clarification from GM if something like this is implemented. It would be pretty easy to do. It offers maximum protection for the battery, and it’s better than being stranded without a receptacle to plug into!

If GM has not implemented this, then why not? Why strand someone because of battery temperature when you have an ICE?

Here’s another take on the same problem. If I just turn the car on and open the hood, the owner’s manual says the ICE will start. Will it then condition the battery while I wait, no matter what the initial battery temperature?

Also, as an aside, I do not see an equivalent “BATTERY TOO HOT” message. Why not?

Perhaps WOT can answer my questions.
 

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Indeed, therfman, it's recent concerns from folks like you that inspired me to start trying to make sense of this. We'll get to the bottom of it, pun not intended :)
ChrisC.
I like what you are trying to do here, but it wont be easy as putting your finger on some of the actual numbers is quite difficult as they have been somewhat of a moving target of course.But I'll help where I can and for now I can verify a particularly well documented temp of 25F (-4C) as the point where the ICE will be commanded "ON" and the message "ENGINE RUNNING DUE TO TEMPERATURE" appears. (as per Lyle's front page post a few days ago)

Primarily this is to assist the 360V cabin heater in warming the coolant more quickly to insure glass clearing. (remember there is no physical connection between the ICE and battery coolant loops) This engine start will also occur if you used your remote start button or smart phone command to pre-condition the car at colder than 25F. (as documented inthe owners manual)
In either case the ICE will shut off after reaching 150F (65C) (providing you still have sufficient SOC to support all-electric operation) or until ICE temp drops gain.

Of course any "numbers" we document here are subject to change of course, in the event the Volt's calibrations are updated for any reason. Hopefully over the course of the next few weeks though we should be able to create a bit of a guideline as to what to expect based on colder ambients.
My plan was to start a new thread with a reprint of my cooling loop article but havnt got to that as of yet. Perhaps it would be better to just include it a as a post here? Maybe the group can help to decide...

Regards
WopOnTour
 

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Shaft
I think you are perhaps making a bit too much of these messages in the owners manul but...
First of all, keep in mind the ICE coolant cannot directly heat the battery as their coolant loops are not common. (as per my article) Generally the battery is heated via the 360V heater. So if ICE was to contribute any heat to the battery it would have do accomplish that through charging operations due to any generation taking place while ICE is running. (and does so anytime the vehicle has stabilized to an ambient of ~25F (-4C) as per my post above)

To the best of my knowledge the scenario where the "BATTERY TOO COLD, PLUG IN TO WARM" message might appear is going to be a very rare occurance when there is some reason why ICE cannot or will not start (low SOC, out-of-fuel or some other problem) AND very cold ambient conditions and then only after a cold soak of many hours has taken place under those conditions.(the insulation of the battery is such that it dramatically slows heat loss from the battery)

I'm trying to get a defined number for battery temps and better clarification when this might actually occur but at this point I know that it is somewhere near or just below -25C (-13F) but in that event the only way to get the vehicle operational is to either plug it in or have the ICE issue rectified/repaired.
HTH
WOT
 

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Thanks WOT for the info! I'll merge in as soon as I can, by the end of today for sure.

Another key bit of info, that may be public already but I haven't found it, is what is the low temperature spec on the ICE? Failing that, what is typical for ICE?

I'd rather you kept the discussion here, but that's me. I hate forked threads :)
 
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