Charged EVs Interviews General Motors’ Top Electrification Engineers On 2016 Chevrolet Volt

OCT 28 2015 BY MARK KANE 30

2016 Chevy Volt Cutaway - Definitely Not A Mid-Motor Electric Car

2016 Chevy Volt Cutaway

Last month, Charged EVs had the pleasure of speaking about the new Chevrolet Volt with Andrew Farah, 2016 Volt Chief Engineer, and Larry Nitz, head of Hybrid and Electric Powertrain Engineering.

While we advise that you check out the whole interview, a few things drew our attention in the already highly exploited drivetrain topic.

First is the larger gasoline engine in gen-2 Volt (1.5-liter four-cylinder instead of 1.4-liter). According to GM, the larger motor brings few advantages.

Larry Nitz said:

“The engine is larger and more powerful, and that is useful not only for efficiency, but also noise and vibration. We can keep the engine more in the background than we could in the first-gen Volt. Overall it’s better in multiple ways. More efficient, more powerful, quieter, and it uses regular fuel – the first-gen used premium fuel.

Second is to increase the proportion of US-made components from about 50% to over 70%.

Larry Nitz said:

“We’ve gone from about 50% North American content to over 70% North American content – and a lot of that content has also gone from Mexico back to the US. The electronic modules, for example, are now made in Indiana versus Japan. The electric motors are now made in Kentucky versus Japan. The final assembly of the drive system is done in Warren, Michigan versus Mexico. These electronics assemblies are very hands-off type of assembly, with a lot of automation, so we can cost-effectively do them in the US.”

2016 Chevrolet Volt - Now With Illuminated Chargeport

2016 Chevrolet Volt – Now With Illuminated Chargeport

It seems that both the Nissan LEAF and 2016 Chevrolet Volt have cells, packs, electric motors and power electronics made in U.S.

Third is charging improvements of 8-10%. New Volt is still using only a low-power on-board charger for charging – but power output was increased a little bit to achieve similar charging times, despite the larger battery (18.4 kWh vs. 17.1 kWh).

“We’ve learned a lot about charging behaviors and chargers. The charger on the next-gen Volt is 8-10% more efficient. That means that more of the power that you’re taking from the wall goes to charge the battery. The charge times are almost the same as the first-gen Volt even though we store more energy, because the charger is slightly larger and more efficient. The magnetic circuit inside the charger is a point of great development over the last five years, and now delivers really high-efficiency charging – over 90% efficient.”

Source: Charged EVs

Categories: Chevrolet


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30 Comments on "Charged EVs Interviews General Motors’ Top Electrification Engineers On 2016 Chevrolet Volt"

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Wow I’m so happy I have Generation 1 Volt.
Hitachi electric motors made in Japan as are the control modules.

New there was reason the high tech part of My Volt 2013 is so reliable!

Fingers crossed the New Volts gear made in N/A will be just as reliable 🙂

So the 0.3 kW boost combined with the 8-10% onboard charger efficiency increase makes the ’16 Volt charge at an equivalent rate of ~4 kW compared to the Gen 1 Volt (3.3). Still not 6.6, but a little better than first look.

They’re being constantly Coy here. I don’t see why they just don’t compare the old specs with the new specs.

Going from 89% efficient to 90% efficient is an efficiency increase of 9.09%. So its not 4 kw.

And 90.1 % efficiency (“OVER 90 % !!!!) isn’t so spectacular.

IF they still have the old 15 amp limitation that all former GM products had, then you’ll only see this WHOPPING INCREASE at home. At most public chargers (200 volts) you’ll still only get 3kw.

It is apparently much more “fun” to every other month or so, take their new Blue Volt and put in on a turntable and get Pam and Andy and the rest of guys to say we’ve “learned alot about charging behaviors”.

They could just issue a side by side 8 1/2 x 11″ sheet of paper comparison with stats from the old volt and new volt, but things like the 15 amp charger limitation one just finds out in the field.

My friend Brian can charge his old leaf with that “HORRIBLE” 3.6 kw charger at over 18 amps while I’m stuck at 15 on both of my cars.

What? Going from an 89% efficient to 90% is an increase of 1.1%, not sure where you got 9% from.

For the percentage ‘challenged’ going from 89% to 90 % efficiency is going from a loss of 11% to a loss of 10%, so that is a gain in efficiency of 9.09%.

Wouldn’t be just a 10% less inefficiency and a 1.11% gain in efficiency?
Reducing the lose by 10% look good, but when in fact it is just a 1.11 increase in total efficiency, it’s not that awesome.

It can’t be an overall gain because if it was the thing would have only been 80% efficient in the 2011 and that wouldn’t have been nearly enough to satisfy the Europeans for the Opel/Vauxhall Amperea.

Besides, everyone talks their book. How to use statistics to make something sound like a huge improvement.

Hum, not really, going from 89% to 90% efficiency is just 1% gain in efficiency.
Basics physics say’s overall efficiency is power out/power in= overall efficiency.
Yes, you can twist the number in any way you wish but that doesn’t change the efficiency of a system.
Of course this is just the charger efficiency.
It isn’t much, but anything better is good.

0ther than this Premium Fuel thing which s news to me, I think the 0ld Volt Looks better too. The new Volt looks like the 0ld 0utgoing 2015 Honda Civic… BTW…the New Civic Looks very Premium.. Appears Awesome in photos…..

The premium fuel thing was new to me too. In Europe we just use regular euro95 petrol (as is recommended).

I also like the gen1 design, especially the Ampera, which I own. The gen2 won’t be offered in Europe, so I wonder what this means to the resale value.

In Europe we charge with 240volts, so it completes within 4,5hours. Which i find reasonable.

I am still curious if volt/ampera gen1 owners will be offered gen2 replacements batteries. I don’t see why GM remain silent on this. I suggest an upgrade service where the battery is replaced and the old one returns to GM for recycling/refurbish

Europe ‘regular’ (95RON) is roughly equivalent to north american ‘premium’ (91AKI), so no difference to you at all.

On the plus side, GM has licensed every major battery breakthrough. They clearly are the leader, aside from Tesla, in battery tech.

On the negative side, the new Volt is great for single people and people with small kids.

But, the rear headroom is from 1950’s US population survey. It seriously needs an update. They need a Volt-Wagon, which would take sales away from Volkswagen, which needs to suffer in the market. They need a Sport-wagon competitor for: Headroom and space utilization.

Because we want to camping, biking, and hiking in this thing.

Don’t make me buy a CMax!


This is the exact reason I ended up buying a Leaf instead of a Volt a few years ago – I found the Volt to be far too cramped in the back seat, much less usable cargo space, and much less ground clearance. Too bad, because I would have found the drive train to be a better choice in my neck of the woods.

The engineers provide a wide variety of information in the interview. I am interested in how widely GM can apply its Voltec technology. A compact coupe suits me, but most car buyers want more space – a wagon or cross-over and a choice of compact or mid-size. The GM engineers said a little about applying their Voltec components to other vehicles: “GM chose to modularize the Voltec powertrain so that it can be mated with different engines and used in a hybrid or an extended-range EV with minimal changes to the electric drive. This strategy lowers GM’s investment, and increases scale for it and its suppliers, making the whole electrification proposition more cost-effective”. “On the Malibu hybrid we have a larger and more powerful engine, because we don’t have the really big battery. It delivers less than one-third the power that the Volt battery can deliver. Inside the electric drive unit, about half a dozen parts are changed, including one of the motors, which is optimized differently for a hybrid. The Malibu Hybrid will get 47 mpg combined – if that’s not the best, it’s right up there with the best D-segment hybrid in the world. We can do it… Read more »

What I find very interesting Chip is that the new dual planetary gear system with one less clutch actuator in the New Volt will make it seem more like you are driving a new Hybrid Malibu rather than a new VOlt, not vice versa.

Since the wheels and engine are DIRECTLY , and permanently connected, the car should drive much more like a hybrid, and in ‘charge sustaining mode’, what I call ‘dead battery’ mode, the engine will shut down at stoplights just like a hybrid.

Years ago, they had a 2 planetary gear, 2 motor setup for the Cadillac Escalade. They could dust off that design, put a 48 kwh battery in the thing, and a J1772 as an option for plenty of their larger premium vehicles. If you’re gonna spend $100k on a vehicle, it might as well have a decent battery and plug on it.

Questions I would’ve asked.

1. Why they didn’t give Volt DCFC, even as an option. SparkEV has it, Bolt will have it, Volt doesn’t? With DCFC, using gas engine will be practically eliminated in places like CA and OR, and Volt can becomes a real EV, not merely a hybrid.

2. Why give new Volt different battery than SparkEV? At 18.4kWh Volt vs 19kWh SparkEV, they could’ve given it slightly bigger pack to take advantage of the economy of scale.

I like GM EV guys, but sometimes…

The battery in the ’16 Volt uses the same cells that make up the Spark EV battery:

“Volt customers told GM they wanted to go farther on a single charge. GM tested the new Volt’s batteries in the Chevrolet Spark EV.”

Cells are the same from LG, but pack is different. What I meant was to make the packs the same as well so that they’ll cut cost for 10 years that SparkEV needs support. Otherwise, they need to run separate lines for SparkEV packs and Volt packs. Upcoming Bolt will need yet another line.

SparkEV, good questions.
The GM engineers say they chose to make the Voltec 2 powertrain modular, which gives GM the potential advantage of economy of scale. We know the Volt EREV, Malibu hybrid & Cadillac PHEV will use Voltec components.
So I would add question 3:
3. Can the SparkEV & Sonic Bolt BEVs also use Voltec components to maximize economy of scale?

I think GM plans to cut SparkEV when Bolt comes out, so there’s little hope for SparkEV using Voltec. But if they decide to keep SparkEV going, it would be great to reuse existing tech as much as possible as long as they can retain its performance.

But if they cut SparkEV, will it be the collector’s car that EV1 has become? Off topic, I guess.

I think it’s pretty much a given the Spark EV will be discontinued once the Bolt goes into production. The Spark EV was basically a guinea pig for GM to do testing for the Gen 2 Volt, along with the Bolt EV. Why else would they stick an electric motor with 400 lb-ft of torque in a tiny Spark EV?? 🙂

Oh, and GM collected some ZEV credits along the way too. 🙂

I think the power rating of the pack differs so they would require different cooling design. The Volt design is maximizing cooling with cooling plate sandwich each cell.

Spark EV battery doesn’t do that. It only provides two cooling plate for the entire pack.

Thanks for the link bro; interesting article. It explains why the Volt & Bolt battery packs are very different although they use the same cells:
“Plan on at least 50 kWh of capacity. Speaking to that, GM says only that the Chevy Bolt will use a “flat-pack” configuration, bound to consume less interior space than the Volt’s T-shaped battery pack. In other words, the prismatic cells surely will be laid horizontally and built into the floor instead of using the Volt’s vertical alignment. One other cost-, weight-, and space-saving deviation we predict is use of air cooling in the Bolt versus the complex liquid-cooling arrangement seen in the Volt”.
For me, key features of the Volt are liquid cooling & using only the middle part of state of charge.
Liquid cooling & partial cycling extend the life of the battery.
Personally I would prefer a Sonic Bolt EREV with a tiny single cylinder CHP heater/range extender to preserve range in the winter or trickle-charge the battery at 7kW or even 3kW when public destination charges are iced or not working.

It’s only a blog, so I don’t know how much to believe. But if Bolt doesn’t have liquid cooling, will it be as bad as Leaf in DCFC? That thing charges less than 10kW at 80% SoC from 50kW charger. That’ll make for poor EV experience for everyone, including other EV drivers who have to wait to charge.

Seeing how SparkEV has liquid cooling, hmm. I might be keeping my SparkEV for a long, long time.

I saw the telegraph comparing the old and new battery packs. What struck me was the similarity of the electrical interface. Maybe it’s wishful thinking but I wonder if the new battery could be inserted into the Gen 1 battery’s physical form factor and be used as a replacement.

GM did a very unusual thing with the Gen 2 Volt, the powertrain was completely redone. Car makers never do this, particularly on a low volume car that was built from scratch only four years earlier. I believe the reason for this is GM knows that they can make the new Voltec transmission work on just about every light truck and car that it makes. It’s cheaper to build than an conventional automatic and with battery prices coming down, it positions them well to produce everything from battery EVs, plug-ins, and strong hybrids.

Yeah, making the malibu hybrid like this is surely going to be more reliable than competitors’ overly complicated 8 and now 10 speed transmissions.

As you state, just by enlarging the battery, putting their 3.3 or 3.6 charger in the thing, and hanging a j1772 jack on the side instantly electrifies the malibu, and whatever other vehicles they can shoehorn this thing into.

So GM is fully covered as to making the right decision whether gas prices go up or down. If they go up, then they can quickly electrify lines they’ve already converted to voltec hybrids.