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Discussion Starter · #1 ·
Hi all,

I've read many of the threads and my manual about Mountain Mode on my Gen2 and still had some questions as I'm about to embark on a 300 mile round trip for a day without anticipating any way that I can charge up.

My plan is to use Hold for highway cruising (probably 250 miles of 300 mile trip) and Normal for as much of the stop go and low speed traffic as possible still keeping some electric for the end. The stop/go stuff is mostly at either end of the trip. There is also some hilly terrain in between so I could use Mountain or stay in Hold mode which got me thinking about the best way to use modes for the trip

Is Mountain Mode essentially an automatic method of me just manually managing my use of Hold and Normal modes to keep a certain percentage of charge in reserve (lets say 40%)?

Thanks!
 

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Is Mountain Mode essentially an automatic method of me just manually managing my use of Hold and Normal modes to keep a certain percentage of charge in reserve (lets say 40%)?
While that is essentially the gist of it for the Gen1 models, I believe the percentage SOC on the Gen2 models dropped to a much lower level (15%?). I'd suggest that you can probably reserve the use of MM for that occasion when you fill up with gas and forget to reset HOLD mode. Using MM when you totally run out of EV power will bring you back up to a reserve for city driving on EV.
 

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Unless you are crossing the Rocky Mountains or similar you will not need to use Mountain Mode. Just start out with a fully charged battery and a full tank of gas. Switch to Hold on the highway portion of your trip. You can switch back to normal for local driving if you wish, just leave some battery for the return trip. Bring your Level 1 EVSE on the trip. You usually can find a 110V outlet to plug in the Volt, even if only for a few hours. At the 8 amp default setting you will be able to add 2.7 miles per hour of charging, 11 miles in ~ 4 hours. You should be able to arrive back at your starting point with some remaining battery charge and 1/3rd tank of gas.
 

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Discussion Starter · #4 ·
Thanks all. Managing the range with Hold and Normal will be the plan. I will try to scope out an outlet too. Forgot about looking for 110V.

So let's say I manually manage the battery and keep a few bars in reserve at all times. If I come across a steep grade (not Rockies steep by any stretch) I won't do any damage to the car by staying in Hold mode, right? I assume the car will dip into the battery if it needs it, even in Hold (provided I have saved some battery of course).

Thanks again and sorry for all the newb questions :)
 

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I assume the car will dip into the battery if it needs it, even in Hold (provided I have saved some battery of course).
Absolutely. In fact, the car works far better if you never let it run the battery all the way down, for this very reason. And even in hold, going downhill will charge the battery a bit to keep it where it is.
 

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I've only once ever used Mountain Mode and probably never will again as I see little value in it. If you have more than 15% charge state it will immediately use battery until 15% is reached and then will jump to the ICE and use the battery also if extrea torque is required. I have had the Volt fully loaded with luggage and 4 adults up mountain roads in Hold mode only and the 1.5L engine has no problem coping with that.
 

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I crossed the Rockies both ways yesterday on a round trip from Montrose to Salida, CO (131 miles each way, over Monarch Pass, 11,312'). I have mostly been driving our Bolt, but 262 miles is right at the edge of its range, and I'm not a "range anxiety" fan!

I was in Mountain Mode the whole way and was interested to watch the very busy energy flow live graphic. Going up the hills, the range available on electric went from 60 miles to zero pretty quickly, but the graphic continued to show energy flowing from the battery, from the ICE and battery together, and sometimes battery only!

The drive brought home how much more I like the aggressive regeneration on the Bolt, both from "L" and paddle. Way, way better than the Volt, although the Volt driver seat is superior!
 

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Thanks all. Managing the range with Hold and Normal will be the plan. I will try to scope out an outlet too. Forgot about looking for 110V.

So let's say I manually manage the battery and keep a few bars in reserve at all times. If I come across a steep grade (not Rockies steep by any stretch) I won't do any damage to the car by staying in Hold mode, right? I assume the car will dip into the battery if it needs it, even in Hold (provided I have saved some battery of course).

Thanks again and sorry for all the newb questions :)
You won't damage the Volt if you remain in Hold mode. Even if you did not have the foresight to save some bars and were in Normal mode when ascending a steep grade, the only thing that might happen is the Volt would display Reduced Propulsion on the Driver's Information Console screen. In that case you might find your speed limited to below 70 MPH and needing stay in the right lane.
 

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Discussion Starter · #9 ·
Thanks everyone for all the insight and advice. Such a fantastic forum! Looking forward to the trip and playing around with all this stuff. Got to admit though I'm a little bummed that I'm going to have to visit the gas station when I get back!
 

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Thanks everyone for all the insight and advice. Such a fantastic forum! Looking forward to the trip and playing around with all this stuff. Got to admit though I'm a little bummed that I'm going to have to visit the gas station when I get back!
If you are not going to need to use any gas for a while after your upcoming trip the remaining ~ 3 gallons should suffice for quite some time. The Owner's Manual recommends keeping the fuel tank at 1/3rd full if you don't regularly use gas.
 

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Just as a note--so you're not surprised--the "HOLD" mode has a bit of a loose "grip" on the Gen 2 and allows a small bit of battery drain that doesn't get "put back" unless you run at slower speeds for extended periods of time (in HOLD). In other words, you may slowly find yourself losing your battery charge for long uphills at high speeds, until you hit some of the active "recharge windows" for the Gen 2 in HOLD. These recharge windows are usually slower speed (less than 63 MPH) or low engine draw (like going downhill).

There was a story on here a while back about someone who took the Volt across several states using HOLD the whole time and slowly (but surely) depleted most of his battery. He was bummed as he was trying to keep a "full" battery as a reserve (almost like an extra gallon of gas) in case he needed it.

However, his was a long trip and your 300-mile round trip is probably not long enough for you to deplete much of the reserve.

If you're dead set on keeping a small amount (about 9-10 EV miles) in reserve, I would run it in Mountain mode as that tends to work a little harder to make sure the SOC (about 2 bars of battery) are kept "topped off" for when needed, unless you are going to have some of your travel at slower speeds and the Volt has a chance to actively recharge.
 

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Discussion Starter · #12 ·
Great point - why carry it around if I'm not going to use it? Never thought of it that way. Funny how going from my old Volvo to a Volt is a bit of a mindset shift. Thanks!
 

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Discussion Starter · #13 ·
Just as a note--so you're not surprised--the "HOLD" mode has a bit of a loose "grip" on the Gen 2 and allows a small bit of battery drain that doesn't get "put back" unless you run at slower speeds for extended periods of time (in HOLD). In other words, you may slowly find yourself losing your battery charge for long uphills at high speeds, until you hit some of the active "recharge windows" for the Gen 2 in HOLD. These recharge windows are usually slower speed (less than 63 MPH) or low engine draw (like going downhill).

There was a story on here a while back about someone who took the Volt across several states using HOLD the whole time and slowly (but surely) depleted most of his battery. He was bummed as he was trying to keep a "full" battery as a reserve (almost like an extra gallon of gas) in case he needed it.

However, his was a long trip and your 300-mile round trip is probably not long enough for you to deplete much of the reserve.

If you're dead set on keeping a small amount (about 9-10 EV miles) in reserve, I would run it in Mountain mode as that tends to work a little harder to make sure the SOC (about 2 bars of battery) are kept "topped off" for when needed, unless you are going to have some of your travel at slower speeds and the Volt has a chance to actively recharge.
Got it! So if I'm understanding correctly, if EV range starts to slip a bit I could look for opportunities to stay in Hold mode at lower speeds (sub 6o mph but more than stop/go) to try to gain the range back rather than switch over to Normal. Or run MM like you said just to keep the 15% or so reserve.
 

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Just as a note--so you're not surprised--the "HOLD" mode has a bit of a loose "grip" on the Gen 2 and allows a small bit of battery drain that doesn't get "put back" unless you run at slower speeds for extended periods of time (in HOLD).
This is a very frustrating "feature". If I move to "Hold", I want to manage the battery capacity, but the car has other ideas...


If you're dead set on keeping a small amount (about 9-10 EV miles) in reserve, I would run it in Mountain mode as that tends to work a little harder to make sure the SOC (about 2 bars of battery) are kept "topped off" for when needed, unless you are going to have some of your travel at slower speeds and the Volt has a chance to actively recharge.
I believe this is because Mountain Mode engages the "not-talked-about-so-much" gear in the transmission that physically links the engine crankshaft to the wheels. So, the car turns from a true EV in this mode to a Hybrid car. (Engine connected to the wheels, with a battery assist.)
 

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Put it in Mountain Mode and leave it there. When you get off the highway put it back in Normal mode and you'll have 5 to 7 miles of EV range for local driving. The other thing I'm going to do next month (July) when I drive from Denver to New Hampshire and back is take advantage of the battery availability so when I stop at a rest area and for lunch I'll leave the car on but locked with the A/C on Max. The ICE won't be running because I'll have more than enough battery available. Yeah, it'll lower my overall efficiency numbers for the trip but having a cold cabin will be worth the energy consumption.

One other thought - if you're going to be driving across Kansas do it in Mountain Mode. Last summer my 2017 Volt needed all the Mountain Mode help it could get on a relatively flat I-70 due to a 30 to 35 MPH headwind. Combine that with the 75 MPH I was driving and the car had an effective airspeed over the vehicles top rated speed - the ICE engine simply doesn't have sufficient power to drive the car through the air that fast and it needed the battery to assist. I had 0 miles EV range when I got off the interstate in Topeka even though I started with a full charge and was in Mountain Mode all the way from Denver.
 

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Put it in Mountain Mode and leave it there. When you get off the highway put it back in Normal mode and you'll have 5 to 7 miles of EV range for local driving. The other thing I'm going to do next month (July) when I drive from Denver to New Hampshire and back is take advantage of the battery availability so when I stop at a rest area and for lunch I'll leave the car on but locked with the A/C on Max. The ICE won't be running because I'll have more than enough battery available. Yeah, it'll lower my overall efficiency numbers for the trip but having a cold cabin will be worth the energy consumption.

One other thought - if you're going to be driving across Kansas do it in Mountain Mode. Last summer my 2017 Volt needed all the Mountain Mode help it could get on a relatively flat I-70 due to a 30 to 35 MPH headwind. Combine that with the 75 MPH I was driving and the car had an effective airspeed over the vehicles top rated speed - the ICE engine simply doesn't have sufficient power to drive the car through the air that fast and it needed the battery to assist. I had 0 miles EV range when I got off the interstate in Topeka even though I started with a full charge and was in Mountain Mode all the way from Denver.
But, Mountain Mode doesn't do anything until the SOC gets down to 2 bars. Up until then you are driving just like Normal Mode using battery only. Hold Mode should keep most of the remaining SOC and only use the ICE to move the car. Every summer I drive 700 miles from Nashville to Orlando using Hold Mode the entire way. I only lose about 2 bars of charge from the full 10 bars by the time I arrive in Orlando. And that is because when you get off the interstate and come to a stop the ICE shuts off, then doesn't restart until you get up to about 20 mph. All the short stops along the way adds up to the 2 bars of lost charge.
 

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Is Mountain Mode essentially an automatic method of me just manually managing my use of Hold and Normal modes to keep a certain percentage of charge in reserve (lets say 40%)?

Thanks!
I'm thoroughly convinced that the Gen 1 at least uses a more aggressive approach to keeping the battery in the correct window than just letting the battery run down to its set bottom does (Charge Sustain or CS mode). Which is great if you're climbing hills, or will be soon, but does mean that it's a little more prodigal with fuel consumption than CS.

(I'm also thoroughly convinced that gaming with Hold Mode for some perceived economy provides so little benefit that the gains made get offset by failures to turn it off soon enough, resulting in people getting to their next charging opportunity having used gas to preserve a handful of electric miles that are made moot as soon as the thing is plugged in. But I'm seeming pretty alone in beating that drum, and it doesn't really matter much in the long run anyway, so I don't invest much more than saying "No, there's no right way to use Hold Mode to save money" and letting it go.)
 

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Got it! So if I'm understanding correctly, if EV range starts to slip a bit I could look for opportunities to stay in Hold mode at lower speeds (sub 6o mph but more than stop/go) to try to gain the range back rather than switch over to Normal. Or run MM like you said just to keep the 15% or so reserve.
Nope, those things got nothing to do with each other. EV range (as reported on the estimated range figure) will vary by so so so many things that it's not necessary to do anything about it unless you want to save some EV range for some specific reason on this particular trip, or after it (when you don't have a charging opportunity).
 

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This is a very frustrating "feature". If I move to "Hold", I want to manage the battery capacity, but the car has other ideas...
Because that's not what Hold *does*. Hold says "pretend the battery is at bottom charge (low¹) at the state it currently is". How the car behaves when it's at bottom charge is "when you use more than about a half kwh below (low²) this point, use engine-generated power to charge up to get back to low¹" And then the charge floats between low¹ and low². At freeway speeds, there's probably enough extra draw to keep the generator running almost all the time, but you'll see the cycling on and off a lot.

I only lose about 2 bars of charge from the full 10 bars by the time I arrive in Orlando. And that is because when you get off the interstate and come to a stop the ICE shuts off, then doesn't restart until you get up to about 20 mph. All the short stops along the way adds up to the 2 bars of lost charge.
Whenever you turn ON Hold Mode, you're resetting that fake low¹ point to wherever it is at the time. Which means if you turn the car off while it's charging from low² to low¹, it'll come back on as Normal mode, but some fraction of that half-kwh lower than the low¹ you set the first time. Turning Hold on again gets you that new lower fake low¹, with a correspondingly lower low². Do that a handful of times, and you start seeing the behavior you note, where how much charge you've "held" shrinks over several off-on cycles.
 

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Thanks everyone for all the insight and advice. Such a fantastic forum! Looking forward to the trip and playing around with all this stuff. Got to admit though I'm a little bummed that I'm going to have to visit the gas station when I get back!
I had about three gallons left when I got back from the Eclipse last August. I ended up with over 5,000 miles on that gas tank. There are several members here with Gen 1 Volts who routinely put just 2 gallons of gas in their Volts at a time and then run them to empty. This reduces the vehicle weight (not by enough to make a real world difference) but more importantly keeps their cars from ever enter Fuel Maintenance Mode.
 
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