Quote:
Originally Posted by big swede
Let's get real. We are not debating GM's exact settings they are going to use on the production model. There are so many settings to be determined just in the fact of when and how much charging should take place and under a myriad of variable scenarios that I'm pretty sure exact settings are still being worked on and will probably be tweaked on a yearly basis through PCM updates.
The biggest difference you have with GoBlue and I is that you say the Volt will work in a diminished capacity after the 40 miles on battery. That's really the main disagreement I have with you. And no I won't call you the names you called me I will just say we agree to disagree.
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Not so fast. Details count.
For instance, you said,
"I'm actually surprised the ICE would charge it as high as 85%", but in fact so would I as the ICE never recharges the battery. That cycling rate relates to the charge/discharge cycle from plugging it into the mains power.
BTW, for people who talk about having a charge point at work, I will point out that GM in it's instructions to owners would discourage you plugging in at work unless you are close to depleting the battery reserves. The Volt is designed for people who commute LESS than 40 miles per day and if a little more then they can use some gasoline. But the ten year life expectancy of the battery is loosely based upon 1 cycle per day. If your recharge it at night and at work for 2 cycles per day then expect to shell out $10K for a new battery 5 years earlier.
BTW, GM has also spoken of the ICE running at up to three discrete rpm’s with phasing between them so as to smooth out the sound for occupants.
Also, Larry Nitz said they were able to raise the cycle points from 30-80 to 35-85, but able to dip down into the 30+ range. Add to that he said the engine at 50kW (67hp)
"does not have the full power to do the dynamic response [but] that the electric side can, so you do have to depend on the battery". So you can probably conclude the meaning of what Lutz said about the system being smart enough to know if you are close to home and the battery not needing to recharge.
Given the battery has 16kWh, but only accesses 8kWh during the normal cycle, if it dipped down below 35% to say 32.5%, for the 'dynamic responce' the engine can't provide after charge sustain mode is reached, then this amounts to an equivalent energy consumption to a range of 2 miles of driving.
If 8kWh gives 40 miles then 0.4kWh, which is the differential between 32.5% and 35% SOC, gives 2 miles. To recharge up to the sustain level from there would take far more than 2 miles even if the engine is running constantly at it's 50kW maximum. Given that after providing driving power it has a average surplus of 20% then it would take 10 miles driving to get back to the 35% sustain level. But if the computer knows you are not that far from home then it can leave the battery at the sub 35% sustain level and let it be recharged on plug-in.
Oh BTW, as to the Volt having sub-par performance after the electric only, I think the difference will be less than I thought because I now believe that the electric only performance will be a lot less than we hoped. Lutz was quoted as saying,
“Our performance targets for the Volt are 0 to 60 in around five or six seconds. Top speed of 120 miles an hour for a limited time. A hundred miles an hour is sustainable.” Also, given the performance of the Tesla everyone expected good electric only performance. But as recently as his appearance on the Colbert Report it was down to I believe 9 seconds.
Now as to your dispute with me about it's post electric only performance. If you remember correctly I said that it's performance would be equivalent to small Euro economy cars. Even with the battery providing power for 'dynamic responce', to get 50 mpg, it will have to perform like a Euro economy car. It's not like they are snails, just not what Americans are used to.
But now I don't believe that there will be as noticeable a performance loss after electric only simply because now I believe that the Volt won't ever produce the higher level of performance from which to drop much from.
At 9 seconds 0-60 it will not be fast, and I'll bet that they tweaked that off the line benchmark so it doesn't sound as slow as it's normal driving performance will be. And by slow I mean normal economy car slow.
