2016 Chevrolet Volt – Technical Battery Slides Video

MAY 5 2015 BY ELECTRICCARSTV 27

Lots of interesting comparative technical battery info on first-gen and next-generation Chevrolet Volt in this video.

Battery Improvements

Battery Improvements

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27 Comments on "2016 Chevrolet Volt – Technical Battery Slides Video"

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Interesting, but I’m not sure where these slides were presented and by who.

Of course, GM is using a higher SOC window on the new pack so the overall actual pack degradation rate and lifetime may not necessarily be better when the pack is used in actual cars rather than during generic lab testing.

Looks like Gen2 is using 76% of the battery where Gen1 only used 65%.

Yup, efficiency + increased DOD + the 1.X kwh got us to 50.

Well, 76% max, assuming the owner drives until the gas engine comes on every day.

For a whole lot of current Volt owners, that doesn’t happen even today, with shorter pure EV range.

With a longer EV range, even fewer owners will push their cars all the way until the gas motor kicks in.

That means the actual battery degradation for typical drivers will likely not change much if at all. Because in the end, degradation in the real world will be determined by actual discharge between recharges, not on the theoretical maximum discharge before recharge.

ooops, meant to reply to Jeff, my bad. Hit the wrong reply button.

I’m impressed by the great improvement in Longevity beween gens 1 and 2, and even 1 isn’t all that bad typically after 150000 miles.

I notice in the slides that the regeneration time allowed is ’10 seconds’.

So I guess that means towing your Leaf with a Toyota Tundra at 55 mph is not recommended as it won’t quick charge as in the Leaf but will burn something out, either the power electronics or else battery overheating. But all, in all, good show!

That would be 10s sustained at the max rate.
Not sure how a leaf does it, but a volt in L draws nowhere near max regen until you press on the brake some.
Estimate off the top of my head is about half that stated max if you’re at 55mph and let off the accelerator

Still, not a good idea in general to stress out the battery.
Thankfully there’s no need to go to crazy lengths in a volt, just to the nearest gas station 🙂

In my 2011 Volt, I came down Mount Washington in 20 minutes time, using L all the way down. Brakes cool to the touch at the bottom, and my battery went from empty at the top to 60% full at the bottom. 🙂

So I agree with you that the 10 second limitation must be 10 seconds of max regen.

I thought they would have improved a lot more. About 16-18% in 5 years isn’t really that impressive. Seeing how the range improved a lot more, although they lost some battery weight, you can see by how much the original Volt was over engineered.

Based on some of the other charts, not only did they improve range by 25% (40 to 50), and reduce the weight slightly, and fit it into the same volume, they increased the performance over the life of the cell, both the calendar life and the cycle life, compared to Gen 1 and 1.5.

As always, we have to take into account the cost. I’m guessing that the battery has the listed improvements plus a non-trivial cost reduction. GM could easily have put a more impressive battery into the new Volt at a much higher cost, a solution that would have been a bad move, all things considered.

“16-18% in five years is not that impressive.”

Patience Grasshopper.

Just think if steel alloys gained 16-18% tensile strength every five years for the past hundred years or so. That would be impressive. It will be the same for batteries.

GSP

So these cells are less energy dense 173wh/kg compared to the 200wh/kg SK innovation cells in the soul ev and Panasonic’s 18650 cells 263wh/kg in tesla.

But more telling is the volumetric density of 336wh/L which is about half that of tesla’s cells at 650wh/L. I think this is the part the major OEMs missed is their quest to avoid complexity.

I’m pretty sure you’re comparing Apples and Oranges – the Volt properties listed above is probably at the pack level – once you factor in the volume and weight of the module, wiring, safety, and pack.

The figures for the other ones (SK, Panasonic) are at the cell level.

I have read that volt1 whole pack assambly is 435 pounds…

The numbers quoted are all cells. Slide 2 in the video above lists the energy and volumetric density at the pack level which are 101wh/kg and 119wh/L respectively.

I believe the kia soul battery pack weighs in at 282kg which makes its energy density 96wh/kg at the pack level. Which implies that GM has a better mastery in cell packaging as the 2016 volt is 101wh/kg at the pack level despite using lower density cells.

So what are Tesla’s numbers at the pack level?

Tesla is at 142wh/kg at the pack level for the 85kwh pack and 130wh/kg for the 60kwh pack. Don’t know the weight of the 70kwh pack yet.

Ouch! According to those slides, my first-gen Volt is going to have a pretty crappy battery (60% or less?) when I get to 150K EV miles. Makes me think that I definitely will need to replace the battery after 10-12 years. Lets see if GM even offers replacement batteries for sale by 2020!

Wait.

Nevermind. Those chart’s Y-axis is not zero-indexed. It starts at 60 it looks like. So after 150K miles I’ll have 80%, not 60%, left in the battery.

Yep, and mine will likely be time limited vs mileage, looks like about 85% at 15 years.

Looks like mine should be operating quite well for at least 20 years, assuming it doesn’t break otherwise or rust away 😉

One of the most important comparisons between the battery packs of the Volt 1.0 and the 2.0 isn’t in the video at all: cost per kWh. I see some comments above are also comparing the Pansonic/Tesla cells to the LG Chem/Volt cells. Tesla is using much higher energy density cells, so they can cram a lot more kWh into the Model S. This makes sense for Tesla’s approach, which is that performance is more important than cost. Contrariwise, GM (and Nissan and other EV makers) are aiming at the lowest possible price point. It seems pretty clear that LG Chem will soon be supplying a new type of battery with significantly lower per-kWh cost. That’s why we have recently seen several EV makers project selling “200 mile” EVs starting in 2017. If this advancement is only achieved by using relatively low energy density battery cells, that’s not surprising. As with all battery engineering, the manufacturer must trade off different characteristics to maximize the value which is most valued. It’s not a case of apples-and-oranges when comparing the Panasonic cells to the LG Chem cells. But perhaps it’s like comparing apples from two different growers, one of which is breeding the… Read more »

My back of a napkin math puts the Bolt at a 72 kWh battery by these numbers (56 usable).

6900 cells, 713 kg pack, on a sonic body ~ 4,000 lbs. Maybe Tesla’s move to 70 kWh packs was based on competitor info .?.?

Bets on Bolt’s kWh size anyone?

I dunno about a “bet”, but my guess is the Bolt will have a battery pack of around 48-50 kWh.

Don’t make the mistake of thinking a nominally “200 mile” BEV is going to have an EPA range of 200 miles. It will likely be something like 150-160 miles.

As a reminder, the 60 kWh Tesla Model S is a much larger car than the Bolt, with an EPA rated range of 208 miles. You can be sure that the Bolt will have a somewhat smaller pack than that. Even if the Bolt actually had 200 miles of EPA rated range, it wouldn’t require a 72 kWh battery pack, or anything near that big.

The Leaf is a BEV which Nissan advertises as a “100 mile” EV, and has a 24 kWh battery pack. Twice that would be 48 kWh. Of course you can’t get twice the range in the same size car with twice the kWh, due to the law of diminishing returns. But the Bolt is somewhat smaller than the Leaf, so hopefully that will roughly balance out.

I agree with the comment about 200 miles meaning 160 or so EPA miles. I can’t see them putting out a longer range car without them at least hitting the 200 mile range on the old EPA test cycle that California uses to determine CARB ZEV credits.

200 miles on the old test gets GM 1 more ZEV credit per unit they sell in CARB ZEV states. That would be about 160-170 miles on the new (current) EPA test cycle. I’m betting on an EPA rating somewhere between 160 and 200, no matter what GM says between now and when the official EPA number is released.

They should eliminate the section 2 of the battery and in the same time improve the remaining section 1 and 3 to get 100 miles of ev autonomy.

Does anybody know what is meant by Gen1.5?
The 16.5 or the 17.1 kwh battery?