Prius Plug-in and Volt Pros and Cons

What a terrible response, even more vague than before.

A generic reference to lithium batteries tells us what in context to the discussion?

 

Basically the Wikipedia entry says that they shouldn't be charged at temperatures above 45C or below 0 C.

 

Feeding us vague statements, leaving out detail, is what?

More attempts to distract & downplay.

At least everyone got to witness some examples of what happens when a successful technology is challenged by another struggling to be successful too.

It's really unfortunate goals simply aren't stated instead. There's a competitive mindset that blinds some from what they really should be striving for.

 

Which of course is a particularly ironic statement, given that the vast majority of your contributions here seem to be parroting back unfounded claims you read somewhere without any original thought or signs of comprehension. Meanwhile hobbit has dedicated a decade or more to direct research on Prius operation and shared an incredible amount of information and insights with this community over the years.

When your Volt dash looks like this, you might get hobbit level respect.

 

Wow. I'm impressed. I can't wait to see the pics and data you doubtlessly have to share of all that fancy calibrated test equipment in your Volt demonstrating its clear superiority in design and implementation in detail.

Rob

 

Here's a fun experiment in data extrapolation. Taking the ANL D3 data, we can estimate what the relative efficiency of the Volt and a "PIP+" with no changes other than enough battery to utilize a similar amount of AC Wh as the Volt would be on the urban UDDS and highway HWFE driving cycles. Clearly this is a theoretical comparison, but one that I find rather informative regarding the efficiency of HSD design.



For this theoretical case, the PIP+ and Volt would stack up as follows after ~100 miles:

Urban UDDS 14 cycles (104.4 miles)
PIP+: 13.246kWh AC + 0.440 gallons gasoline = 125.5 MPGe
Volt: 13.012kWh AC + 1.205 gallons gasoline = 65.7 MPGe

Highway HWFE 10 cycles (102.5 miles)
PIP+: 12.503kWh AC + 0.569 gallons gasoline = 109.0 MPGe
Volt: 12.753kWh AC + 1.155 gallons gasoline = 66.9 MPGe

Interesting.

Rob

 

Specs show the Volt battery weighs 435 lb and the PiP battery weighs 176 lb – a difference of 259 lb. Hard to imagine the differential in weight would hurt the PiP’s efficiency too badly.

 

To john and anyone else feeding the troll,
You guys do realize there is absolutely nothing you can say that will illicit any sort of mind or thought change with this guy, correct? So why try? You are wasting your time and energy. If he wants to be as bitter as he is, that is his choice. Don't go down to his level.

 

Sometimes, it serves as an effective way to shake out weaknesses.

Notice how he keeps bringing up the TMS, even though GM itself said the initial system was over-engineered?

There's no proof that is actually necessary.

 

That continued generic use of the type "lithium" and seemingly benign use of "asking questions" is very much a greenwashing technique, whether intended or not.

Nissan has been pursuing chemistry alterations to continue use of "lithium" batteries without the need for liquid cooling.

Remember, over-engineering equates to higher cost, preventing the offering from being affordable and competitive.

 

"Over engineering" is in the eye of the beholder.
Lots of backups and redundancies are engineered into cars with the goal of safety and reliability.

Nissan tried building a battery pack without liquid cooling and have been paying the price.
I look forward to their upcoming 'hot tolerant' pack. If they can build a pack without liquid cooling that can stand up to 100% charges in Arizona and such! it wille quite a breakthrough.

As for the graph up above, it could stand with some captions or explanation. However, if this stems from my Prius A vs Prius B hypothetical, there is a lot to be considered when trying to translate a figurative car into a real one.

 

The LEAF pack uses entirely passive thermal management. There is no liquid, air fan, or anything. They count on thermal radiation from the bottom of the steel pack enclosure and that's it. It was a dumb design for cells which are predominantly Manganese which are the most delicate chemistry for heat degradation, I think. On hot Arizona days the heat sinking in from outside air and hot pavement since the battery is purposely not insulated.

The Volt's cells are similar although they also reportedly contain a bit of Cobalt. That's why GM chose to use a liquid cooling system and battery pack insulation. In my opinion, it was a prudent choice and not over-engineering for their first car using a large Lithium ion pack.

I live in a mild climate and drive conservatively and have seen maybe 3% degradation after 3.5 years, 83,000 miles (53,000 miles EV). Owners of LEAFs in my area apparently are seeing 10-15% degradation under similar conditions based on a few random reports I've read or heard about, although I don't have high confidence in the accuracy of that impression.

It will be interesting to see how Ford Energi and Prius Plugin work out with their other chemistries and air fan solutions.

 

Ironically, it was GM who said that.

Also, there's the irony of Volt enthusiasts giving GM praise for taking the risky approach not wanting to acknowledge the reality that the backup/redundancy was included to not take the risk.