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Discussion Starter #1
Has anybody tried Mountain Mode (MM) while State of Charge (SOC) of battery is high (over 45%) in EV mode?

It is known that if you shift to MM in Charge Sustain (CS) mode engine would top the battery up to 45% SOC as well as providing enough power for current driving power demand.

I am just wondering if we shift to MM when SOC high (say 80%), Does the engine kicks on and sustain the battery charge at (80%) or Volt just drain the battery to designed 45% SOC even in mountain mode.

Imagine I want to save battery charge for city driving at the end of 40 mile highway. So I can shift to MM during highway to save battery charge for using the charge in city instead of highway in which the petrol engine operates efficiently.
 

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It's the latter. It lets it go down to 45%, or whatever the number is. Ask Rusty.
 

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I don't know what the number is, but I do think the driving style of the car changes in MM operating in CD. There seems to be less acceleration for one. Diving at 80% SOC MM seems to be like "anti-sport" mode...
 

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I don't think you can go in MM until about 11-13 EV miles left. This is what I found on two drives in Chicago and from what the engineer said. Don't know how that translates to SOC tho.
 

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I don't know what the number is, but I do think the driving style of the car changes in MM operating in CD. There seems to be less acceleration for one. Diving at 80% SOC MM seems to be like "anti-sport" mode...
Its probably something very simple, but can I ask you what "CD" and "EVSE" mean?
 

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I don't think you can go in MM until about 11-13 EV miles left.
No, you can switch to MM any time you want. Your EV range drops instantly by about a dozen miles, and you continue on in CD mode until EV range drops to zero. Only then does the ICE fire up.
 

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Discussion Starter #7
Thanks MichaelH & Rusty

I live in Melbourne Australia, GM/Holden would introduce Volt to Ausi market in 2012 at least according to their website.

Many suburbs around Melbourne or many other cities in Aus are at least 30 miles away from CBD.

I am just thinking of somehow save the battery energy for low speed driving in CBD and low speed suburb area and turn the engine on in Cruise mode in highway where engine operation is efficient.

It looks funny but my idea is using MM even in high SOC. I reckon the so-called "anti-sport" situation in CS mode is because of the allocation of pat of engine power for charging the battery from low SOC up to 45% (or whatever) and preventing the battery to help required burst of power for acceleration in MM. However, when the SOC is already high the engine power should be able to cover power demand of powertrian. Specially in cruise mode when the sporty driving is normally not necessary.

What do you reckon?
 

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I live in Melbourne Australia, GM/Holden would introduce Volt to Ausi market in 2012 at least according to their website.

[snip]

I am just thinking of somehow save the battery energy for low speed driving in CBD and low speed suburb area and turn the engine on in Cruise mode in highway where engine operation is efficient.
Maybe you'll get lucky, and GM will give you Ausi's the same thing they're supposed to give the EU folk in the Ampera.

Hold Mode

Which, from what I'm told, does exactly what you (and I, and a lot of other people) want. At whatever SOC you activate it, the car drives like normal CS mode maintaining that SOC. When you get to town (or when you're trying to sneak in at 3:00 AM without waking the wife) you switch back to Normal, and you have your full remaining CD range available.

Yes, MM will kinda do that. But it really aggressively tries to maintain battery SOC. So MM sucks gas much faster than normal mode, from what I've seen.
 

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Well, that brings up another issue. Rusty and I were answering for US market. In Europe, the Opel Ampera is going to have a different mode called HOLD Mode. This will do exactly what you are asking for, hold at the SOC you are currently at. I don't know whether Holden will have HOLD mode or not. We just know that Volt in USA does not.
 

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Discussion Starter #10
Thanks Guys,

Perfect. I hope the "Hold Mode" would be a feature of Ausi Volt. It should be only software modification in energy management of Volt to add such a feature.
 

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It should be only software modification in energy management of Volt to add such a feature.
Yup. It should be only software modification in energy management of Volt to add such a feature to the US Volt as well.

So far, GM's response to "some of us would like that" is best characterized as "Huh? No you don't."
 

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If you know that your trip will require more miles tha your battery can supply and part of the trip will be at 70 mph, then using the Mountian or Hold mode to reserve battery power for parts of the trip that are mose efficent on battery, makes sense.
 

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So far, GM's response to "some of us would like that" is best characterized as "Huh? No you don't."
I'd also like Hold Mode on future US Volts. I want to use my electric miles at my destination, not burn them up in the first 30-40 minutes of my 8 hour trip. I hope CARB and EPA regs are not making such a feature difficult to offer.

GSP
 

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I would like to have Hold Mode also. It is very cold here now and much of the energy from the battery is used to heat the cabin (and probably the battery too).

Hold mode would allow me to use the waisted energy from the ICE to heat the cabin and then switch to battery to maintain cabin temperature.

Although I preheat on electric now, It usually does not actually warm the cabin enough by the time I leave so it is still using a lot of battery to heat

Jim K.
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I hope CARB and EPA regs are not making such a feature difficult to offer.
As long as it's not a default mode, I wouldn't think the EPA would have a problem with it. I mean, mountain mode is already in there. "Hold" just gives you a little more control.

But it really aggressively tries to maintain battery SOC. So MM sucks gas much faster than normal mode, from what I've seen.
Theoretically, when MM begins maintaining that 45% SOC, it will just be in regular CS mode and should need no more energy from the ICE than if the SOC were fully depleted and it entered CS mode. Only when you enter MM below the 45% threshold (or wherever that threshold really is) would it need more net power from the ICE than was needed to move the car.
 

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I tried MM one day that I knew I was going to go up a mountain grade and I had 23 miles left on the battery. When I put it in MM the battery miles instantly dropped to 13 left but the ice did not start till the battery went to 0. I than went up a 8% grade 4 miles long and at the top I went back to normal and had 6 miles batt remaining. Going down I left it in low most of the time and went about 27 mph except a couple times went to drive to get some speed up. When I got to the bottom I had 26 miles of battery left and drove in drive home and battery reacted same as if I had charged from the cord. Regen works.

Roy #272
 

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I than went up a 8% grade 4 miles long and at the top I went back to normal and had 6 miles batt remaining.
What speed were you going up the hill? That's about a 1700' climb, right? I would think you should be able to do that in Normal Mode without suffering reduced power, even at 70 MPH. But if you went down the hill at 27 MPH, I'm thinking you didn't go up the hill at 70 MPH...
 

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One downside of the Hold Mode idea is added complication: 4 modes instead of 3.

I've used Mountain Mode to preserve battery range, so that I can demo the car properly (full EV) later in the day. Mountain Mode feels a bit rough to me, compared to CS mode. I've stopped using Mountain Mode unless I really want it. For example, at a stop sign the ICE seems to keep running in Mountain Mode, whereas in CS mode the ICE seems to shut down more quickly and easily. For me, Mountain Mode is sufficient for special occasions, and not something I will use often. That said, I fully admit that my needs likely are not the same as others, especially those Volt owners who have longer and hillier commutes.

On a related topic, some people have suggested the Volt's driving selection be persistent, so that the Volt "remembers" the user selection. I can see the other side of that argument. Having the Volt "forget" the special driving selection (Sport or Mountain) is not so bad, because in Normal mode the Volt tends to use a little less electricity and/or gasoline.

Truth be told, I thought that I had been running in Sport/Low all along (for the last three weeks), and was surprised to discover that I've been running in Normal/Low. In hindsight this probably has given me a few more miles every day, and thus saved a few pennies. The Volt certainly has been no less fun to drive!

So, I'm kind of glad that the Volt forgot that I had selected Sport two weeks ago. And now when I select Sport, WHOA, giddyup!!!

Just my 2 cents, and not worth more...

Chris
 

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Has anybody tried Mountain Mode (MM) while State of Charge (SOC) of battery is high (over 45%) in EV mode?......

Imagine I want to save battery charge for city driving at the end of 40 mile highway. So I can shift to MM during highway to save battery charge for using the charge in city instead of highway in which the petrol engine operates efficiently.
I didn't notice this discussion when it first started 2-3 weeks ago.

Yes, I've been doing exactly this for the same reason on my occasional weekend drives which include 35-40 miles of highway before reaching the destination city. Otherwise, the other 80% of my driving is on battery.

Over the last 2 months of following this pattern, I have driven a total of 367 miles in hybrid gasoline mode for an average of 41.2 mpg at speeds of 60-65. It works great. It's great to exit the highway at my destination, flip back to normal mode, and have 14-17 miles of preserved EV power for my city driving pleasure.
 
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