[jvandonsel]

How does the heater control cabin temperature? I would expect that the resistive heater would modulate on and off as the cabin temperature hovers around the set point, in the same way that your home heating system does.

Instead, I've observed that the GOM always shows the same degradation throughout my trip, rather than bouncing up and down as the heater kicks on and off.

So I can think of two things that could be going on:

1) The GOM smooths over the bumps as the heater kicks on and off. This seems unlikely since I assume that it's just measuring total current draw.

2) The heating element is ALWAYS on when the heater is on, and the cabin temperature is controlled by mixing in outside air. This seems unlikely since it's so wasteful.

I've observed this in Auto and Manual heat modes. I have a 2019 Bolt, by the way.

Thoughts?

 

[GJETSON]

The GOM is smoothing. Showing range based on instantaneous current draw would make it useless.

 

[Openair]

The Gom smoothes the peaks and valleys of the draw of the heater but, if it is cold enough, the heater is also always on. The heater is not binary. It is not either on or off. It can be dialed to produce only enough heat to maintain temperature. Depending on the amount of time in question it is also often more efficient to maintain a temperature than to return to that temperature. Especially as the heater is warming coolant which in turn is used to heat the cabin and not directly heating the cabin. Turning the heater completely off, allowing the coolant to cool down would just mean spending even more power to warm it up again before heat could be directed to the cabin.

 

[Sean Nelson]

Instead, I've observed that the GOM always shows the same degradation throughout my trip, rather than bouncing up and down as the heater kicks on and off.

Look at the power meter on the right side of the instrument cluster to see the power going on and off. It's easiest to see when you're stopped and the motor isn't drawing any power.

The range estimate shouldn't change as long as you don't turn the HVAC system on and off - it's purpose is to tell you how far you can go based on current conditions, including whether the heat is being used. If that range were going up and down just because the heater is cutting in and out it would just confuse people. Heaven knows they get confused enough about it already just due to normal variations in driving and conditions.

 

[jvandonsel]

The GOM is smoothing. Showing range based on instantaneous current draw would make it useless.

Certainly there has to be smoothing, but my question was more along the lines of: On average does the GOM report a higher value when the heat is set at 60 vs 80 degrees, or does it just add a constant penalty when the heat is on?

 

[One1whaoo.]

IMHO, it seems to be a constant percentage of the charge state.
With a near-full charge, I always see the GOM drop by 12-13 miles when I turn the heat on, but recently I noticed that with a 40% charge, turning the heat on only dropped the guess by 7-8 miles.

 

[NewsCoulomb]

IMHO, it seems to be a constant percentage of the charge state.
With a near-full charge, I always see the GOM drop by 12-13 miles when I turn the heat on, but recently I noticed that with a 40% charge, turning the heat on only dropped the guess by 7-8 miles.

Based on my observations, the Range Estimator is overly conservative for the first half of the battery and gets progressively more accurate. When I leave for my long trips at this point, the Range Estimator almost always tells me that I have no chance of making my first stop. By the time I am about 75% of the way there, it tells me that I'll have 15 to 20 miles to spare.

 

[GJETSON]

Certainly there has to be smoothing, but my question was more along the lines of: On average does the GOM report a higher value when the heat is set at 60 vs 80 degrees, or does it just add a constant penalty when the heat is on?

Yes. The heater varies the current through the heating element, as well as turning it on and off, to maintain the temperature you set. This effects the GOM reading just as variations in current through the drivetrain caused by terrain change, speed, and wind effect it. None of these effects show up immediately. The only time I have noticed an immediate change, is right after charging the car. The GOM number then, with no miles driven, will move back and forth, by turning the heat on and off.

 

[mikewill44]

My question is related, but slightly different. It seems that with our 2018, the regulation works like, if it's set for 74, and the heater brings it up to 75 or 76, instead turning off and letting it cool down, the AC kicks on, until it's back down to 74 (or lower). If I'm correct about what's happening, it seems dumb. Also, no apparent way to change it.

 

[XJ12]

My question is related, but slightly different. It seems that with our 2018, the regulation works like, if it's set for 74, and the heater brings it up to 75 or 76, instead turning off and letting it cool down, the AC kicks on, until it's back down to 74 (or lower). If I'm correct about what's happening, it seems dumb. Also, no apparent way to change it.

Do you live in an area with high humidity? These days cars have humidity sensors and use the air conditioner to dry the air.

 

[One1whaoo.]

The only time I have noticed an immediate change, is right after charging the car. The GOM number then, with no miles driven, will move back and forth, by turning the heat on and off.

The change in the GoM is immediate when turning the heat on/off in my 2017, and is as I described above - usually 12-13 mile immediate loss of estimated range.

 

[NY-Rob]

My question is related, but slightly different. It seems that with our 2018, the regulation works like, if it's set for 74, and the heater brings it up to 75 or 76, instead turning off and letting it cool down, the AC kicks on, until it's back down to 74 (or lower). If I'm correct about what's happening, it seems dumb. Also, no apparent way to change it.

I have read mention of that behavior in the past, and I have experienced it myself on several occasions.

If you overshoot the setpoint (or suddenly/drastically lower it below the current cabin temp) the Bolt will activate the A/C system to bring it back down to setpoint... then the heat will come back on again.



The workaround is to just hit the "Heat & A/C" button on the touchscreen to power down the climate control while still leaving the fan on.

 

[Like2bike]

My question is related, but slightly different. It seems that with our 2018, the regulation works like, if it's set for 74, and the heater brings it up to 75 or 76, instead turning off and letting it cool down, the AC kicks on, until it's back down to 74 (or lower). If I'm correct about what's happening, it seems dumb. Also, no apparent way to change it.

The 2019 solves this problem by having separate HEAT and A/C ON/OFF controls. I still find the heat operation worse than my LEAF when I turn down the heat a little. The LEAF would just cut back the power being used and the temperature would slowly drop. The Bolt seems to blow a lot of cold outside air to lower the temperature quickly. One thing I like about the Bolt climate control is the AUTO mode allows you to be in a partial AUTO mode. It can do AUTO fan speed only or AUTO recirculate only. Full AUTO mode will still do the switch right from HEAT to A/C when you turn down the temperature though.

 

[Belmo]

What is a GoM?

I'm fluent in English, French, 50% German and 50% Spanish and not there yet in acronyms, sorry.

I participate in another forum specialized in technical cave diving and I know a lot of aviation acronyms in both those fields, I'm not there yet in Boltology, please excuse me.

 

[Fivedoor]

What is a GoM?

I'm fluent in English, French, 50% German and 50% Spanish and not there yet in acronyms, sorry.

I participate in another forum specialized in technical cave diving and I know a lot of aviation acronyms in both those fields, I'm not there yet in Boltology, please excuse me.

Other EV's also use the term GOM... It stands for Guess O Meter. It is your range estimate.

Keith