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Discussion Starter #1
If the Bolt is plugged in, but not charging, and the ambient temperature drops, and the Bolt decides to begin warm-up conditioning, then how much power in Watts will it take from the mains?

Thanks, all.
 

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If the Bolt is plugged in, but not charging, and the ambient temperature drops, and the Bolt decides to begin warm-up conditioning, then how much power in Watts will it take from the mains?

Thanks, all.
Depends on how cold, I think 2-3kW at marginal (~30F), maybe few more kW as temps drop around 0F.


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From my observations from many people and myself playing with Bolt EV on 2020 it will never exceed 1960 watts....older versions may have different software... in most extreme cold weather -20°F
having a Bolt seating outside plugged in for 24 hours ... it will consume around 3-6 kWh ( at this cold even ICE with 120V coolant heater will not be far away)... this may be too much but I only do extreme scenarios with my Bolt. And I'm not afraid of living in outside on -25°F unplugged. My research has lead that engineers at GM took in consideration that not very efficient aluminum plates are not getting any better from going over 2 kwh . I have 2 packs from Bolt that I have disassembled for other EV projects.
The best in the EV world heat management is Volt design ....Porsche Taycan (Audi EV) and Rimac design. Tesla is not bad but far from being leading design. I have seen personally all of them including recent visit to Rimac factory....
If they decided to continue with Volt battery management design GM would be absolutely best in the business ( but it is expensive to make big packs and space limitations are another factor).
I hope that future brings really the best from competitors in EV world.
To me Volt is one of best battery management's that I personally advise to people who are looking for ultimate HV battery heat management.
 

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Discussion Starter #5
I am not sure that I made it clear that this is a question about battery warm-up conditioning after charging is complete, but ambient temperature falls below freezing for lengthy time. This is not about HVAC in the cabin. If EV Engineering is correct, 1960 W at 120 V (OEM brick) is ~16 A. But the car will limit the feed to 8 A or 12 A. Half the amps at 240 V.
 

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I wonder about the benefits of plugging in the car while parked in cold weather. The car is ready to drive at full performance. That's obvious. But it draws power constantly for that. 500w average for 6 hours is still 3kwh per night. I would rather park the car unplugged. When the car starts, propulsion and regen may be reduced for a few miles. No biggies.

-TL

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I wonder about the benefits of plugging in the car while parked in cold weather. The car is ready to drive at full performance. That's obvious. But it draws power constantly for that. 500w average for 6 hours is still 3kwh per night. I would rather park the car unplugged. When the car starts, propulsion and regen may be reduced for a few miles. No biggies.
Yup. My biologist buddy in New York state is much more concerned about CO2 than driving performance. He leaves his unplugged, outside. He wears a snowmobile suit.
 

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Yup. My biologist buddy in New York state is much more concerned about CO2 than driving performance. He leaves his unplugged, outside. He wears a snowmobile suit.
I'm more concerned about my wallet. Waste of any kind is no good.

-TL

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Discussion Starter #9
I wonder about the benefits of plugging in the car while parked in cold weather. The car is ready to drive at full performance...
This post is concerned with power consumption during battery temperature protection, not drive-away performance. I know the car will drive, with reduced range, at below zero temperatures. The manual states that the car will warm or cool the battery during ambient extremes. I have actually heard the coolant sloshing around in the pump when it's below zero. The Q was, during that warming and circulation process, how much power is used.

Finally, I ask because I have two Bolts, but the garage has a 15 amp breaker. So if both cars decide to warm their batteries, will they each sink 8 amps, or something less? The manuals are silent. Thanks.
 

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This post is concerned with power consumption during battery temperature protection, not drive-away performance. I know the car will drive, with reduced range, at below zero temperatures. The manual states that the car will warm or cool the battery during ambient extremes. I have actually heard the coolant sloshing around in the pump when it's below zero. The Q was, during that warming and circulation process, how much power is used.

Finally, I ask because I have two Bolts, but the garage has a 15 amp breaker. So if both cars decide to warm their batteries, will they each sink 8 amps, or something less? The manuals are silent. Thanks.

Here are the results for a 2017 in 20 F weather.

 

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This post is concerned with power consumption during battery temperature protection, not drive-away performance. I know the car will drive, with reduced range, at below zero temperatures. The manual states that the car will warm or cool the battery during ambient extremes. I have actually heard the coolant sloshing around in the pump when it's below zero. The Q was, during that warming and circulation process, how much power is used.

Finally, I ask because I have two Bolts, but the garage has a 15 amp breaker. So if both cars decide to warm their batteries, will they each sink 8 amps, or something less? The manuals are silent. Thanks.
If you don't care about the drive-away performance, you probably don't need to consume any power plugging in your car.

-TL

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That are my findings but at 0 or -20°F they are much shorter between kicking in to maintain while plugged in. On other hand Tesla 3 will be using up to 7 kWh if both stators are called to heat battery. And on average with ghost drain and battery management Tesla will use 2-3 more energy than Bolt. And while unplugged Tesla is less tolerant to cold gate and it will have half of what Bolt will allow to be sent to propulsion motor.
 

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... On other hand Tesla 3 will be using up to 7 kWh if both stators are called to heat battery...
How do 'stators heat the battery'?
Is there not a resistive heater in the battery TMS loop on a Model 3?
7kW is a lot of battery heating.
I suppose part of these numbers need to consider the amount of insulation battery packs have to the outside world.
 

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....Finally, I ask because I have two Bolts, but the garage has a 15 amp breaker. So if both cars decide to warm their batteries, will they each sink 8 amps, or something less? The manuals are silent. Thanks.
Pretty sure it's 8A max for the car on default 120V whether Charging and/or Battery Heating.

So: two Bolts at 8A each on one 15A circuit is not the way to go.
Time to open the Ol'Billfold and add a circuit to the garage.
Or go cheap and get a 12ga. extension cord and plug on of the 120V chargers into a different circuit somewhere else in the house! :rolleyes:
 

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How do 'stators heat the battery'?
Is there not a resistive heater in the battery TMS loop on a Model 3?
7kW is a lot of battery heating.
I suppose part of these numbers need to consider the amount of insulation battery packs have to the outside world.
Tesla S and X has one but Tesla 3 and Y is using stator while seating still ( humming noise coming from the drives) and with octovalve is feeding coolant straight from motors to the battery pack.
While fast charging sessions Tesla pack's are getting heated all the way to 64°C before cooling will kick in.
It is different chemistry and thermal management design that also contribute to seeing this type of safe temperature of +60°C.
 

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... Tesla 3 and Y is using stator while seating still ( humming noise coming from the drives) and with octovalve is feeding coolant straight from motors to the battery pack...
Thanks for the info.
That sure seems like a wasteful round about way to get heat to the battery pack.
'Heat the stators' to get some of that heat to the battery pack.
This must also be heating the rotors and magnets in them, no? And the inverters are making heat providing the power to the stators.
And these drive units are not insulated from the cold.
So a lot of this 7kW of heat is lost way before making it to the pack.
Stators front and rear, octovalve where? and circulating coolant pump sending it to the pack inlet.

This is compared to the 2kW coolant heater the Bolt uses just for battery heating.
And this 2kW must be variable such as when plugged into a 120V EVSE, I assume.
 

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Thanks for the info.
That sure seems like a wasteful round about way to get heat to the battery pack.
'Heat the stators' to get some of that heat to the battery pack.
This must also be heating the rotors and magnets in them, no? And the inverters are making heat providing the power to the stators.
And these drive units are not insulated from the cold.
So a lot of this 7kW of heat is lost way before making it to the pack.
Stators front and rear, octovalve where? and circulating coolant pump sending it to the pack inlet.

This is compared to the 2kW coolant heater the Bolt uses just for battery heating.
And this 2kW must be variable such as when plugged into a 120V EVSE, I assume.
It is sacrifice Tesla engineering team had to do to eliminate dedicated battery heater.... it is definitely far from being efficient while stationary.....
While driving and you have entered destination charger....on all wheel drive front will have stators on including rear drive that move car to keep heating battery over octovalve loop.
 

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This is compared to the 2kW coolant heater the Bolt uses just for battery heating.
And this 2kW must be variable such as when plugged into a 120V EVSE, I assume.
Yeah. Even the Bolt has the heater, pump, tank, and several feet of hose uninsulated, outside the battery box.

I get that it would be potentially dangerous, and hard to service, if this stuff was in the battery box. Design is always compromise.
 

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.... Design is always compromise.
I agree, but having the motor stators heat up to heat up the coolant flowing through them is a weird heat source, to me....
Those motors are a large mass of steel, copper, magnets, lube and aluminum.
They are just sitting out there, out in the breeze, and they are located far from the coolant inlet to the pack.

A 'half-a-shoe-box' size 2kW coolant heater tucked in somewhere makes engineering sense, to me... :unsure:

Maybe a Tesla fan can explain why this the way to warm the pack.

So the octovalve is just a fancy coolant director valve?
I thought at first it had something to do with a heat pump system.
Remember you need heat and AC to defog the windows sometimes.

If a Bolt and a Model 3 are parked out in the 2°F driveway for 48 hrs, both plugged in and topped up, what would the energy cost differences be for running these TMS systems?
 
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