[Protege]

Hey fellas. I'm just having a hard time understanding pre-conditioning. I've turned off engine assist by the way. Also turned off heated seats. Anyway, at home after a full charge 110v/8-amp, I pre-conditioned the car before going out for a drive. The indicated range is 81km according to my app. By the time I stepped in the car and started it, my estimated range came down about 2 km to 79km. My understanding is that the house electricity is providing the necessary juice to heat the car to preserve battery capacity. I'm thinking maybe it's because 8 amps is not powerful enough, and the car has to draw power from the battery. So, I went to 2 ChargePoint terminals on 2 separate occasions. Both terminals indicate 6.6kwh of power at 20amps I think. So on one occasion, I had the chargepoint fully charge the battery and then pre-condition. Again, I lost estimated range....ie. the car drew power from the battery.

The second test I did, I went to a different ChargePoint location (also 6.6kwh), but this time I left the car on - Parked with parking brake, turned off exterior lights. I had eco heat on and the satellite radio going. According to ChargePoint, my car is charging and feeding juice into the car. But of course, my estimated range went down also. According to my DIC, the car is using about 2kwh of power, but with 6.6kwh from the charger, there should be 4.6kwh charging the battery. Is there something I'm missing here?

 

[lagagnon]

In my experience pre-conditioning the vehicle with 120VAC even at 12 amps is a waste of time (at 8 AMPS forget it!).

It takes a full 50 minutes after the 10 minute precondition cycle to recover to a full charge.

Now that we have a Level 2 (240VAC) EVSE at the full 16A (maximum draw of a Volt) it pre-conditions nicely and only takes about 2-4 minutes after that 10 minute cycle to fully recharge whatever battery it had to use to do the preconditioning.

YMMV because the amount of preconditioning and the power used I understand to be somewhat dependent on what the vehicle senses the internal and external temperatures to be at the time you start it. That is probably why you are seeing different results a the ChargePoint locations.

 

[AtomicPowered]

Level 2 charges at about half the power that the cars heater uses. It can take 10 minutes after preconditioning to get that back in the battery. Depends on how hot you want the car.

 

[jcanoe]

Hey fellas. I'm just having a hard time understanding pre-conditioning. I've turned off engine assist by the way. Also turned off heated seats. Anyway, at home after a full charge 110v/8-amp, I pre-conditioned the car before going out for a drive. The indicated range is 81km according to my app. By the time I stepped in the car and started it, my estimated range came down about 2 km to 79km. My understanding is that the house electricity is providing the necessary juice to heat the car to preserve battery capacity. I'm thinking maybe it's because 8 amps is not powerful enough, and the car has to draw power from the battery. So, I went to 2 ChargePoint terminals on 2 separate occasions. Both terminals indicate 6.6kwh of power at 20amps I think. So on one occasion, I had the chargepoint fully charge the battery and then pre-condition. Again, I lost estimated range....ie. the car drew power from the battery.

The second test I did, I went to a different ChargePoint location (also 6.6kwh), but this time I left the car on - Parked with parking brake, turned off exterior lights. I had eco heat on and the satellite radio going. According to ChargePoint, my car is charging and feeding juice into the car. But of course, my estimated range went down also. According to my DIC, the car is using about 2kwh of power, but with 6.6kwh from the charger, there should be 4.6kwh charging the battery. Is there something I'm missing here?

When you precondition the Volt the electric heating element in the cabin cooling/heating coolant loop will draw between 4 and 8kw for the 10 minutes preconditioning cycle. If you are plugged in using Level I charging at 110V and 8 amps you are only receiving ~900w from the EVSE while charging. You are running a power deficit of greater than ~4kw so you will end the preconditioning cycle with less than a full battery charge. If you are plugged into a Level II EVSE the Gen 2 Volt draws a maximum of 16 amps at 230V or 3.6kw. You still run a deficit but in my experience the preconditioning cycle will end with between 0.2 - 0.5 kWH of the battery capacity having been used. It does not matter if the EVSE is capable of delivering 6.6kw or more, the Volt uses only uses a maximum of 3.6kw.

There is no reason to turn off the Automatic setting on the heated seats. Use the heated seats and heated steering wheel (if equipped) to help stay warm. These are powered by the 12V APM not by the high voltage battery pack, the energy used by the 12V accessories including the heated seats, steering wheel and rear defroster does not even register on the Driver Information Display. When powered on the Volt consumes 0.5kw and that readout does not visibly change if you have the audio system blasting out tunes and the heated seats, steering wheel and rear defroster running.

Unless you are only driving a short distance, i.e. less than 8 - 10km, then let the Engine Assist Heat function in the standard mode (not deferred). At temperatures below 35F/2C the gas engine will automatically start and will quickly warm up the engine coolant to ~145F/65C, then cycle off the engine, to help heat the cabin. The gas engine will cycle on and off to maintain the coolant temperature between 120 - 140F / 50 - 60C, heat the cabin while using just a little gas. If you set Engine Assist Heat to the Deferred setting the gas engine will not run until the outside temperature falls below 15F/-10C.

 

[ClarksonCote]

The second test I did, I went to a different ChargePoint location (also 6.6kwh), but this time I left the car on - Parked with parking brake, turned off exterior lights. I had eco heat on and the satellite radio going. According to ChargePoint, my car is charging and feeding juice into the car. But of course, my estimated range went down also. According to my DIC, the car is using about 2kwh of power, but with 6.6kwh from the charger, there should be 4.6kwh charging the battery. Is there something I'm missing here?

If the car says you're using 2kW, that factors in the 3.6kW of juice from the ChagePoint, so you're really using something like 5.6kW of power. (note, the Volt's on-board charger is rated for 3.6kW so you won't pull more than that even at a 6.6kW station)

Similar story with a 120V outlet, you can get about 1.5kW from that at 12 amps (or just under 1kW at 8 amps), so if your car is using 5.6kW, you'll still be using about 4-4.6kW from the battery during a remote start when plugged in.

You can mitigate some of this by using Eco instead of Max on your climate control, but it will still pull more than 1.5kW when heating is needed.

 

[rhodomel]

Does the preconditioning warm up the battery coolant and the battery? If so, up to what temperature?

 

[jcanoe]

Does the preconditioning warm up the battery coolant and the battery? If so, up to what temperature?

There is some debate about whether the preconditioning cycle warms the battery pack in addition to warming the cabin. Anytime the Volt is plugged in the temperature management system maintains the battery pack within an acceptable range of ~40F to 95F. If you precondition the Volt while not being plugged in then it may be that only the cabin may be heated but during preconditioning the Volt is running so the TMS may also use some power to heat the battery. When you are driving in EV mode the TMS may use some power to heat the battery, typically this shows as Other: 2% battery usage. The exact upper temperature cutoff for battery heating is unknown but probably ~60F.

 

[rhodomel]

There is some debate about whether the preconditioning cycle warms the battery pack in addition to warming the cabin. Anytime the Volt is plugged in the temperature management system maintains the battery pack within an acceptable range of ~40F to 95F. If you precondition the Volt while not being plugged in then it may be that only the cabin may be heated but during preconditioning the Volt is running so the TMS may also use some power to heat the battery. When you are driving in EV mode the TMS may use some power to heat the battery, typically this shows as Other: 2% battery usage. The exact upper temperature cutoff for battery heating is unknown but probably ~60F.

I notice that after preconditioning, when I drive the car, there is still some good amount of residual heat blowing into the cabin for the next 10 minutes or so even if the cabin heating is off, so I figured it might be recirculating some air near the warmed up battery pack.

 

[jcanoe]

I notice that after preconditioning, when I drive the car, there is still some good amount of residual heat blowing into the cabin for the next 10 minutes or so even if the cabin heating is off, so I figured it might be recirculating some air near the warmed up battery pack.

Following preconditioning the air from the cabin vents will feel warm for ~10 minutes because the electric heating element warmed the coolant in the cabin heat exchanger coolant loop. The warmed coolant will continue to heat the cabin for ~10 minutes. The battery heating/cooling loop is separate from the cabin loop. The gas engine coolant loop can provide heat to the cabin heating/cooling loop through the cabin heat exchanger once the engine coolant is sufficiently warm. If you ever look under the hood you will find three coolant overflow tanks: engine, battery and high voltage electronics. These overflow tanks are on separate coolant circuits. The cabin coolant loop enables warm engine coolant to be exchanged with the engine coolant loop when you have the climate control system turned on and the temperature setting is sufficient to require heating the cabin. If the gas engine is not running or the engine coolant is not sufficiently warm the cabin coolant loop can be heated via an electric heating element provided you have the climate control set to Economy or Max while heating.

You can experiment with the cabin heat, try setting the cabin temperature to 75F but turn off the Economy or Max heating mode. When running in Hold Mode or Mountain Mode you can display the engine coolant temperature on the driver information center. Once the engine coolant reaches ~160F then the engine coolant will begin to heat the cabin, you will start to feel warm air from the cabin vents. In cold weather while driving at highway speeds this can take 5 - 7 minutes (5 - 7 miles of driving with the gas engine running) to get the engine coolant sufficiently warm to heat the cabin. If you have the electric heat set to Max then warm air will start to blow from the cabin vents much sooner while using ~7kw of power. If the gas engine is running it is generating up to 47kw while powering the Volt and maintaining the battery charge level so you won't be depleting the battery range using the electric heat while the gas engine is running. Once the engine coolant is sufficiently warm the Volt will reduce the amount of electric heat required, may cut off the electric heating element.

 

[rayr3004]

For 2 years I've been going crazy deferring the engine assist to 15 degrees and using just the heated seats. This year I'm going to be comfortable when I need it. This year I changed to the default of 35 degrees. I bought gas in March and this week, December. That's not a bad run. The beauty of the Volt is that it has the engine to assist with heat. Full EV cars don't have this and have to use their battery for heat. We're fortunate to have the ICE to help us out. That's how the car was engineered. Enjoy your ride and don't worry about running the ICE. I'm enjoying my rides much more now that I'm warm. My opinion.

 

[jcanoe]

For 2 years I've been going crazy deferring the engine assist to 15 degrees and using just the heated seats. This year I'm going to be comfortable when I need it. This year I changed to the default of 35 degrees. I bought gas in March and this week, December. That's not a bad run. The beauty of the Volt is that it has the engine to assist with heat. Full EV cars don't have this and have to use their battery for heat. We're fortunate to have the ICE to help us out. That's how the car was engineered. Enjoy your ride and don't worry about running the ICE. I'm enjoying my rides much more now that I'm warm. My opinion.

Engine Assist Heat works well as long as you are driving more than just a few miles, else the gas engine will not have a chance to warm up the engine coolant to help heat the cabin. If you enable Engine Heat Assist Plugged In, safe to do as long as you are not preconditioning while parked inside a garage, then the engine coolant will be sufficiently warm to heat the cabin when you unplug the Volt following the end of the 10 minute preconditioning cycle.

 

[hploeg]

OP said: Hello fellas.
What about the gals on this forum?

 

[Cord]

If you want a warm battery then have charging end 5 mins before leaving for work

 

[Paulacton84]

Hey fellas. I'm just having a hard time understanding pre-conditioning. I've turned off engine assist by the way. Also turned off heated seats. Anyway, at home after a full charge 110v/8-amp, I pre-conditioned the car before going out for a drive. The indicated range is 81km according to my app. By the time I stepped in the car and started it, my estimated range came down about 2 km to 79km. My understanding is that the house electricity is providing the necessary juice to heat the car to preserve battery capacity. I'm thinking maybe it's because 8 amps is not powerful enough, and the car has to draw power from the battery. So, I went to 2 ChargePoint terminals on 2 separate occasions. Both terminals indicate 6.6kwh of power at 20amps I think. So on one occasion, I had the chargepoint fully charge the battery and then pre-condition. Again, I lost estimated range....ie. the car drew power from the battery.

The second test I did, I went to a different ChargePoint location (also 6.6kwh), but this time I left the car on - Parked with parking brake, turned off exterior lights. I had eco heat on and the satellite radio going. According to ChargePoint, my car is charging and feeding juice into the car. But of course, my estimated range went down also. According to my DIC, the car is using about 2kwh of power, but with 6.6kwh from the charger, there should be 4.6kwh charging the battery. Is there something I'm missing here?

your volt does not ever draw 6.6 kw: 230 volts times 20 amps is 4.6, thats all it can draw, it can't siphon off more power on the side all the inlet power goes into the charger first, which is the limiting hardware on EVSE draw.
also you are experiencing in part the difference in range estimate that is the difference between startup range estimate and in trip range estimate- when you start your Volt, it calculates your range estimate based on recent driving history, a few hundred miles I think, others think some differently. once you are driving, the range estimate algorithm changes to take into account how your driving is going on this trip, so if you are going up a steep hill for a couple of miles on teh highway, the range estimate will very quickly think that you are going to continue doing so, and similarly if you are going down a long hill. how does this affect you? you might ask- simple, during a pre heat, you are using power but not driving- so the range estimate algorythim ( there is only one i think, but it takes into account the current trip heavily) realized that you are using power 3 or 4 kw, and going ZERO miles, and if you keep doing that until the battery is gone, you will have zero range on that charge, So my advice is to stop worrying about the range estimate and enjoy your volt!

 

[hellsop]

your volt does not ever draw 6.6 kw: 230 volts times 20 amps is 4.6, thats all it can draw, it can't siphon off more power on the side all the inlet power goes into the charger first, which is the limiting hardware on EVSE draw.

Roughly right, but it can draw that and a lot more from the battery pack. Which is what's going on.

 

[Protege]

Thanks for the responses guys and gals. This is the type of info lacking all througout the web, dealerships, etc. The dealership doesn't know, which makes me wonder why they are even "Volt Certified" to begin with. A lot of the reviews on youtube are ripping the Volt...kindly. But thanks. Now I know that pre-conditioning takes 10 minutes and another 5 minutes or so to top up the battery...and of course, it draws power from the battery. And I didn't know about the 3.6kwh max input. Stuff like this is not being discussed anywhere else.

 

[2VoltFamily]

I notice that after preconditioning, when I drive the car, there is still some good amount of residual heat blowing into the cabin for the next 10 minutes or so even if the cabin heating is off, so I figured it might be recirculating some air near the warmed up battery pack.

No. Heating the cabin has nothing to do with the coolant from the battery pack. The warmth you feel is just residual heat in the coolant loop for the cabin heat, nothing more.

 

[JRRF]

For 2 years I've been going crazy deferring the engine assist to 15 degrees and using just the heated seats. This year I'm going to be comfortable when I need it. This year I changed to the default of 35 degrees. I bought gas in March and this week, December. That's not a bad run. The beauty of the Volt is that it has the engine to assist with heat. Full EV cars don't have this and have to use their battery for heat. We're fortunate to have the ICE to help us out. That's how the car was engineered. Enjoy your ride and don't worry about running the ICE. I'm enjoying my rides much more now that I'm warm. My opinion.

A further question would be which is cheaper (depending of course on what you pay for gas and electricity). Assuming range is not an issue during your drive, is it cheaper to keep engine assist heat off and just put the thing in Max and let the battery warm you. Or is it cheaper to turn on engine assist heat and let the ICE cycle and warm the cabin?

 

[DarrenHD]

A further question would be which is cheaper (depending of course on what you pay for gas and electricity). Assuming range is not an issue during your drive, is it cheaper to keep engine assist heat off and just put the thing in Max and let the battery warm you. Or is it cheaper to turn on engine assist heat and let the ICE cycle and warm the cabin?

At least here, (In Canada), gas is considerably more expensive than electricity, especially off-peak rates (7 pm to 7 am in Ontario). 6 cents per kWh...+ taxes of course, but still far far cheaper than gas.

If you have short commutes, can drive fully inside the EV Range, even with MAX climate settings in Winter, and of course can charge overnight at home, then I say go for it: use the battery to keep you warm and defer ERDTT. That is my use case: My commute to work is 25KM or 15.5 miles (there and back). That still is enough to use MAX climate settings whenever I need them + I still have range left over to run errands after work. Sure, my EV range is considerably crippled, down to an estimated 62km (38 miles) or so in cold sub-zero temperatures, but hey, I still have enough EV juice to do it, so why not?

 

[JRRF]

At least here, (In Canada), gas is considerably more expensive than electricity, especially off-peak rates (7 pm to 7 am in Ontario). 6 cents per kWh...+ taxes of course, but still far far cheaper than gas.

If you have short commutes, can drive fully inside the EV Range, even with MAX climate settings in Winter, and of course can charge overnight at home, then I say go for it: use the battery to keep you warm and defer ERDTT. That is my use case: My commute to work is 25KM or 15.5 miles (there and back). That still is enough to use MAX climate settings whenever I need them + I still have range left over to run errands after work. Sure, my EV range is considerably crippled, down to an estimated 62km (38 miles) or so in cold sub-zero temperatures, but hey, I still have enough EV juice to do it, so why not?

Here the equation is flipped. Gas is relatively cheap, but electricity is more like .15/kwh. So I wonder whether heating with gas might be cheaper.