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I had 9 miles EV remaining and placed my 2017 Volt in mountain mode, expecting it to add miles by charging the battery. It did not after driving for 20 minutes and I'm wondering if I misunderstand and it's not supposed to.

ChuckJ
 

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Mountain mode in a gen2 doesn't charge up as much as mountain mode on a gen1. On a gen 1 you can go from 0 miles to about 14. But it doesn't matter, don't try to use mountain mode to charge the battery to try to game the system, just use mountain mode when you are driving up and down mountains. That's what it's for. There probably aren't many mountains in DFW. Maybe when you take to volt to the Rockies...
 

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Mountain mode in my 2015 volt will get you 27 ev miles total.
I did this as an experiment letting my ev miles get down to 2, and it took 20 minutes and 3/10 gallon of gas to reach the 27ev miles
 

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The 2017 MM buffer is only ~9 miles of power, so you were already around that point when you switched.

Under some power demand situations (say, when driving fast up steep hills), the maximum instantaneous output of the generator may be insufficient to maintain performance. For such situations, GM created a "mode" to preserve a buffer of battery power above the normal minimum level for use if extra power is momentarily needed. Such situations most often occur in rugged, steep terrain, hence: "Mountain Mode."

The ability to charge a depleted battery back up to the MM-maintained soc, if needed, instead of requiring the driver to stop and plug into the grid to recharge before heading into the mountains, is a "feature" of MM, not its purpose. The Gen 1 MM-maintained reserve is ~4 bars of power. That’s been reduced to ~2 bars for the Gen 2 models because of increased gas mode output power.
 

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The 2017 MM buffer is only ~9 miles of power, so you were already around that point when you switched.

Under some power demand situations (say, when driving fast up steep hills), the maximum instantaneous output of the generator may be insufficient to maintain performance. For such situations, GM created a "mode" to preserve a buffer of battery power above the normal minimum level for use if extra power is momentarily needed. Such situations most often occur in rugged, steep terrain, hence: "Mountain Mode."

The ability to charge a depleted battery back up to the MM-maintained soc, if needed, instead of requiring the driver to stop and plug into the grid to recharge before heading into the mountains, is a "feature" of MM, not its purpose. The Gen 1 MM-maintained reserve is ~4 bars of power. That’s been reduced to ~2 bars for the Gen 2 models because of increased gas mode output power.
Does Mountain Mode do anything other than switch to Hold Mode (charge sustain) at a higher threshold? Is the algorithm for power delivery of distribution between drive and charge the same?
 

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Does Mountain Mode do anything other than switch to Hold Mode (charge sustain) at a higher threshold? Is the algorithm for power delivery of distribution between drive and charge the same?
As far as anyone's been able to tell, that's it: Hold Mode but at a point that's OTHER than the State of Charge you're already at. Everything else (leaving the engine off as long as SOC is above the point, running the engine hard if something depletes charge substantially below that point, etc) doesn't seem empirically different between HM and MM. If they'd thought someone would want it, they could have made that Hold Point user-settable in the DIC somehow and combined it all. But that would have required planning and forethought to use, and we'd end up with religious wars about whether it was ever necessary to set it higher than 40% AER, etc, and people reeling it up and down thinking they're getting longer range, dogs and cats living together, anarchy...
 

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Does Mountain Mode do anything other than switch to Hold Mode (charge sustain) at a higher threshold? Is the algorithm for power delivery of distribution between drive and charge the same?
But that would have required planning and forethought to use, and we'd end up with religious wars about whether it was ever necessary to set it higher than 40% AER, etc, and people reeling it up and down thinking they're getting longer range, dogs and cats living together, anarchy...
.... the concept of Volting....(in before the lock) or Voltamorting
 

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Does Mountain Mode do anything other than switch to Hold Mode (charge sustain) at a higher threshold? Is the algorithm for power delivery of distribution between drive and charge the same?
It is unclear if MM is anything more than a variant of Hold mode where the computer, not the driver, selects a specific soc setting to be "held" (plus the ability to recharge a battery to that soc point), or if it is designed to provide a method of ICE operation specifically engineered for conditions where heavier demands on performance might be expected.

I’ve not seen any references to technical documentation suggesting the propulsion system operates differently in MM than in Hold mode at that approximate soc. Nor, I suspect, have any Volt drivers recorded data from their own tests to see if the gas motor’s fuel consumption rates when driving in MM (under various low to high torque conditions and speeds with the soc at the MM-maintained level) differ when driving in those same conditions using Hold mode at the same soc (i.e., the MM-maintained soc level). Is it possible, for example, that when driving through level terrain at freeway speeds with the battery soc at the MM-maintained level, your gas mileage goes up or down merely by switching from MM to Hold?

The combinations of terrain and environment that create circumstances where heavier demand for power could be anticipated or required exist outside of the car. I would think that if the engineers had created MM specifically to increase efficiency under higher-demand conditions (i.e., an operational distinction between MM and Hold), GM would not have bothered to tweak the size of the Gen 2 MM-maintained buffer. Some are not even sure a buffer remains necessary with the increased gas mode power. Removing MM would remove the curiosity about any operational difference between MM and Hold.
 

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Mountain Mode's primary utility is to manage a larger battery buffer, which can be useful when you encounter mountains (or other prolonged inclines). In Gen 1, the ICE is only capable of ~80hp, and limited by a 55kw MGA (generator). Coupled with a drained battery, if you did not engage MM well in advance, you could end up in reduced propulsion mode when encountering prolonged, steep inclines.

Gen 2 has a more powerful ICE, and probably dips deeper into battery reserves, so it may not build up the same amount of buffer as as Gen 1 when MM is engaged.

Regardless, MM is not intended to charge the battery. You can do it but it is not as very efficient.
 

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But that would have required planning and forethought to use, and we'd end up with religious wars about whether it was ever necessary to set it higher than 40% AER, etc, and people reeling it up and down thinking they're getting longer range, dogs and cats living together, anarchy...
Yes, the anarchy thing, I could see it coming the instant I read the thread's title. ;-)
 

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Regardless, MM is not intended to charge the battery. You can do it but it is not as very efficient.
My Gen 2 doesn't appear to recharge the battery at all in MM; is this everybody else's experience too, or is something wrong with mine and the OP's Volts?
 

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Such situations most often occur in rugged, steep terrain, hence: "Mountain Mode."
"Rugged"? Ha! No stock Volt is going into rugged terrain anywhere.

Hold also periodically puts charge back into the battery (even going uphill!). So unless you are completely depleted of charge, there is likely little use for MM.
 

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My Gen 2 doesn't appear to recharge the battery at all in MM; is this everybody else's experience too, or is something wrong with mine and the OP's Volts?
Are you testing it with a depleted battery? As noted in post #4 above, it won't do anything if your SOC is already above the ~9 mi buffer of MM. If it won't build your SOC from 0 mi to ~9 mi, then it's broken.
 

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Are you testing it with a depleted battery? As noted in post #4 above, it won't do anything if your SOC is already above the ~9 mi buffer of MM. If it won't build your SOC from 0 mi to ~9 mi, then it's broken.
Yes battery was at 0 (forgot to charge last night) so tried driving to work in MM so I can remote start the air conditioner on without it running the ICE tonight. Anyway, drove 44 miles and still a zero miles range. Is that not normal?
 

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My 2017 will only hold a max of 7 miles in mountain mode.
 

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Yes battery was at 0 (forgot to charge last night) so tried driving to work in MM so I can remote start the air conditioner on without it running the ICE tonight. Anyway, drove 44 miles and still a zero miles range. Is that not normal?
I think I recall that with a drained battery, the guessometer will say 0 miles, but the battery might charge and show a gray level instead of a green one. When you shut the volt off and back on again, that meter will show 9 miles (or 14 miles for a gen1).

But if you were to attempt this with 1 or more miles left on the guessometer, it will show the miles increasing to 9 (or 14) in green when in MM.
 

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I think I recall that with a drained battery, the guessometer will say 0 miles, but the battery might charge and show a gray level instead of a green one. When you shut the volt off and back on again, that meter will show 9 miles (or 14 miles for a gen1).

But if you were to attempt this with 1 or more miles left on the guessometer, it will show the miles increasing to 9 (or 14) in green when in MM.
You sir are correct.. just checked my app and it says I have 7 miles range.
 
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