Mountain Mode to save battery State of Charge

[Shams]

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.

[MichaelH]

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

[Rusty]

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...

[scottf200]

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.

[Clintonfitz]

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?

[Rusty]

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.

[Shams]

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?

[Rusty]

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.

[MichaelH]

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.

[Shams]

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.