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Discussion Starter · #1 ·
I gather from reading the Bolt user's manual that the vehicle should be always plugged in when parked in low temperatures. I am trying to determine what the power consumption is for this "keeping the battery warm" function. I have mailed (snail mail) GM about it but received no reply.

Does anyone have any info as to what one could expect for a vehicle parked in, for example, -20F or, other low ambient temperatures?

Also, would the battery suffer damage if not plugged in in low temperatures?

Thanks for any help....
 

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I gather from reading the Bolt user's manual that the vehicle should be always plugged in when parked in low temperatures. I am trying to determine what the power consumption is for this "keeping the battery warm" function. I have mailed (snail mail) GM about it but received no reply.

Does anyone have any info as to what one could expect for a vehicle parked in, for example, -20F or, other low ambient temperatures?

Also, would the battery suffer damage if not plugged in in low temperatures?

Thanks for any help....
It is not mandatory to plug the car. The high-voltage battery is used for the conditioning if the car is not plugged. In the energy graph, the energy used appears as "Battery Conditioning".

With the car plugged-in, my ChargePoint station indicates (through the app) peaks of about 2,75 kW during very cold nights. The conditioning occurs several times in the night, depending on how low the temperature goes. I would say about one conditioning event per 2 hours (again, highly dependent on temperature). A conditioning event lasts about 20 minutes.

The only thing you really need to avoid is to have a close to empty battery when the temperature is really low and the car is not plugged in.
 

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Discussion Starter · #3 ·
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Thanks CyberKnight. I was hoping for a better (lower consumption) figure as, if my calculations are correct, the numbers you give result in a power consumption, if left plugged in for an entire month, of about 330 KWh (which is about equal to my current household consumption for the same period in winter).

However, if the vehicle is not to be driven for say a week, it appears one could leave it unplugged up until maybe a few hours before driving, without damage to the battery(?) (sorta similar to leaving an ICE unplugged until a while before use). I believe this kinda ties in with leaving the vehicle at the airport for a week in cold weather, for example.

OTOH, if the battery charge itself is used for the cold weather conditioning, then leaving it unplugged won't reduce consumption if I understand it correctly...
 

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Does anyone have any info as to what one could expect for a vehicle parked in, for example, -20F or, other low ambient temperatures?
 

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Discussion Starter · #5 ·
Thanks XJ12, that is just what I'm looking for. From your graphs it looks like average consumption at -15C is about 4 to 5 KW which gives a monthly consumption of about 330 KWh (which is the same as my calculation in my previous post).

You also show a total of 106KWh over 18 days which equates to about 180 KWh over a month at avg temp of -6C (which is in good agreement with the above).

The average January temperature in Calgary is about -8C (-3C high & -14C low) so it looks like I could expect a monthly consumption of maybe 200KWHs (which would cost about $50 here).

One question though - I'm not sure what you mean by "draw from the charger is 1/2 what it really is". Does that mean your actual power consumption is twice what was measured??
 

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Does on method use more electricity than the other?

If you leave it unplugged and it conditions using the battery power then it has to be charged off the grid power.

If you leave it plugged in it conditions the battery but any power used is immediately made up for off the grid.

So, is the amount of power purchased from the grid the same, either way?
 

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Does on method use more electricity than the other?

If you leave it unplugged and it conditions using the battery power then it has to be charged off the grid power.

If you leave it plugged in it conditions the battery but any power used is immediately made up for off the grid.

So, is the amount of power purchased from the grid the same, either way?
When plugged in, the set points for battery conditioning are more aggressive. Also, when unplugged, battery conditioning will not occur if the State of Charge is less than 40%. So over time, more power may be used for conditioning if the Bolt is left plugged in vs unplugged.
 

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When plugged in, the set points for battery conditioning are more aggressive. Also, when unplugged, battery conditioning will not occur if the State of Charge is less than 40%. So over time, more power may be used for conditioning if the Bolt is left plugged in vs unplugged.
But it is better for the long term life of the battery to have it plugged in and better "conditioned". Uh... long term life... None of the current batteries will have a long term life. At least not in the car. Nevermind. :p
 

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But it is better for the long term life of the battery to have it plugged in and better "conditioned"
It is though? Everything I have read about lithium ion batteries suggests that they are not harmed by cold, unless they get really cold (below -40°C) or you try to charge them too fast while they are cold. Weather cold enough to cool the battery to -40°C doesn't really happen anywhere in North America where there are roads, and the BMS will limit the charge rate to safe levels based on the battery temperature. I frequently see temperatures in the -20°C to -30°C range in winter, and I only plug my car in if it needs charged (SOC at 45% or less). Power and regen are limited if the car has been left unplugged in the cold for an extended period of time, but it doesn't really make any difference because power and regen are usually traction limited when it is cold. I just don't see the point of wasting energy so the car can keep the poorly insulated battery at 15°C when it is -25°C outside.
 

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When plugged in, the battery is kept in top operating condition. You will have full power available the moment you start driving. When unplugged, the objective of battery conditioning is to keep the battery in safe zone. There shouldn't be any harm to battery life unless the battery totally depletes.

It is too expensive (>300kwh per month) just to have full power to leave the drive way. I have no problem to have reduced propulsion for the first few miles.

-TL

Sent from my SM-N960U using Tapatalk
 

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It is too expensive (>300kwh per month) just to have full power to leave the drive way. I have no problem to have reduced propulsion for the first few miles.
Agreed. It would be nice if the Bolt had a setting for that like the Kona does. A performance mode where the battery would be kept at 15°C to keep full power and regen available, an eco mode where the battery temperature would be allowed to drop to 0°C at the cost of somewhat reduced power and regen, and a super-eco mode where the battery would be allowed to cool to -15°C, resulting in perhaps 1/3 power and minimal regen until the battery warms up.
 
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