Key attributes

[FutureFolly]

GM made a lot of big decisions with the Spark EV that most other manufacturers didn't make. These decisions will hugely affect its success as it branches into other markets, and I would like to more fully explain why. I can see that they have real plans for the Spark. Nothing about the project was half hearted.

-They fully designed the motor in house.
-They used lithium iron phosphate batteries.
-They developed water cooling AND heating for their batteries.
-They prioritized fast DC charging over a 6.6KW on-board charger.
-They used the Spark, a city car, instead of the Sonic, a proper subcompact.
-They priced it to be economical to buy, as well as lease.

The Motor:

Everything about the motor is brilliant. A drive shaft runs through the motor so it can be lower to the ground. The motor is oil-cooled, like the Tesla, making it more thermally stable than only water cooling. It reaches maximum power at just 2000RPM and has a redline of 5500 RPM, meaning it has gobs of untapped potential.

The Batteries:

Lithium iron phosphate was a good choice for the batteries. They have lower charge-density than other electrodes, but it tolerates being fully discharged well. They also have a long cycle life. This means the range shouldn't drop off as quickly, preserving the utility of the vehicle for more miles. Without water cooling the batteries, DC-fast charging would need to be infrequent. Without water heating the batteries, Winter driving range would be more severely hurt. The secret key to BEVs success will be year-round drivability. The real range of a BEV is its range under the worst driving conditions after 75K miles, while the driver is acceptably comfortable.

The Chargers:

The 3.3KW on-board charger is one of the few marks against the Spark. Realistically, the more I thought about it, 6.6KW chargers are just trying to fill the gap DC-fast chargers should be filling. Nothing is improved when using 120V outlets. Both are restricted to 15 amps. Right now if you have 240V charging at work, you could use the full charge from your battery one-way, go to lunch in the car, and have a full charge ready for the return trip. Adding a mile every 3-minutes versus a mile every 6-minutes isn't helpful in a ton of situations. In most circumstances it either isn't fast enough or time wasn't that important. On the other hand, adding three miles every minute would be helpful lots of times. Obviously it can only be helpful if the DC-chargers actually exist, which is a big hurdle. In 10-years I think people buying it used will care more about the DC-fast charging than the 3.3KW on-board charger.

6.6KW charger will definitely be an option in a year or two just to stay on-par with the competition and appease people with range anxiety. Logically, I would assume it will be packaged with the DC-fast charger just to simplify GM's inventory.

The Car:

The Spark. You could say it was destined to be an EV. When I first heard about the Spark coming to the US I assumed it was an electric car. I sort of did a double take when I heard that it was a gas car with rumors of a planned electric version. While it seems obvious, the Sonic would have been much more marketable to Americans. The Spark had key attributes that make it the perfect platform. The most important is weight. By adding so many pounds of batteries it weights as much as a Cruze but less than most EVs. The weight also allows the suspension to be tuned close to a Cruze for a comfortable highway ride with an amazingly low center of gravity and near even weight distribution. Using the Sonic would have added 400 pounds, costing range and adding cost. I would also say they almost salvaged the Spark from being a crap car. If you could get a DC-fast charge at 50% of gas stations there would be no logical reason to get the gas Spark.

The Price:

Going with the Spark also allowed them to price the Spark ultra-competitively. Starting with a $12K car made in Korea gives them a lot of pricing power while trying to reach profitable scale. The success of BEVs depends on them being more economical to buy than gas cars, and 5-year cost of ownership reviews have proven that the Spark is a good investment for a large niche of the population. Most manufacturers have exclusively been relying on generous lease prices to meet their mandates.

 

[cwerdna]

The Chargers:

The 3.3KW on-board charger is one of the few marks against the Spark. Realistically, the more I thought about it, 6.6KW chargers are just trying to fill the gap DC-fast chargers should be filling. Nothing is improved when using 120V outlets. Both are restricted to 15 amps. Right now if you have 240V charging at work, you could use the full charge from your battery one-way, go to lunch in the car, and have a full charge ready for the return trip. Adding a mile every 3-minutes versus a mile every 6-minutes isn't helpful in a ton of situations. In most circumstances it either isn't fast enough or time wasn't that important. On the other hand, adding three miles every minute would be helpful lots of times. Obviously it can only be helpful if the DC-chargers actually exist, which is a big hurdle. In 10-years I think people buying it used will care more about the DC-fast charging than the 3.3KW on-board charger.

Re: the 3.3 kW OBC vs. a higher wattage one, besides being able to opportunity charge and replenish range more quickly, it also can help free up L2 spots more quickly.

At my work, we had (long story about why it's had) a ratio of ~4:1 of EVs/PHEVs vs. L2 J1772 handles and we observe good charging etiquette and sharing practices. If all else is equal, the 6+ kW OBC cars will finish more quickly and be able to free up their spot for someone else.

I've plugged in, started sessions of Volts at my work before, then watched their charging graphs before (via Chargepoint's web site). I can see at 208 volts (what our EVSEs run at), Volts only pull ~3.1 kW and I can see how many kWh they've drawn over a given amount of time vs. my Leaf, which tends to pull ~5.8 to 6.0 kW.

As for your last statement, unfortunately, it's almost a certainty that J1772 L2 AC public charging stations will remain FAR more common than any DC fast charging equipment. The cheapest DC FC is the http://nissanqc.com/ (CHAdeMO only) and is $15.5K, not including installation and other costs. The average cost to install one of those at Nissan dealers was $49K (I'm assuming that includes the $15.5K). The unit requires 480 volt 3-phase power.

Even w/o such power requirements, a high powered DC FC will likely run into issues w/demand charges due to their high power draw within a small window of time. J1772 L2 EVSEs are much cheaper from an equipment and ancillary cost point of view.

I'd bet that in 10 years, that vast majority of pure BEVs running around will have 6+ kW OBCs. I'm reasonably certain they already make up the majority of BEVs judging by Model S and 2013+ Leaf sales in addition to the small numbers of other 6+ kW OBC EVs (e.g. Rav4 EV, FFE, Fit EV, Fiat 500e, etc.)

 

[FutureFolly]

That 4:1 ratio seems ridiculous. I would be campaigning with management until the ratio was AT MOST 2:1. If an employee can invest in an EV, the employer should be willing to invest in an EVSE for every employee. I commend you and your EV loving coworkers for working together to make the resources work for everyone. Early adopters need to work as a team. You clearly get to know each other on a first name basis. Lol

The real scam electricians pull is not prewiring commercial locations for more EVSEs than the customer wants to install. Running extra conduits is no big deal. Digging up earth and potentially cutting asphalt and concrete is a big deal. The electrician may put in a sub-panel that is too small as well. It's a shame because it makes businesses think the cost of electrifying each parking space is greater than it should be.

 

[cwerdna]

That 4:1 ratio seems ridiculous. I would be campaigning with management until the ratio was AT MOST 2:1. If an employee can invest in an EV, the employer should be willing to invest in an EVSE for every employee. I commend you and your EV loving coworkers for working together to make the resources work for everyone. Early adopters need to work as a team. You clearly get to know each other on a first name basis. Lol

It's actually not bad at all. We have no formal rules and we have an internal voluntary list (actually, not so voluntary now) for the self-serve stations. We can't complain too much as almost everyone is so courteous and charging is free. It's not a requirement or a mandate that employers provide any EV charging, free or not. Many employers who provide EV charging charge for it.

I have no problems w/contention or having to free up a spot if I start charging at say 4 or 5 pm. I leave late anyway. I intentionally now don't park in an EV spot in the morning or early afternoon, to make way for others. And, because I have a 6 kW OBC, it doesn't take me long. I can get from say 50ish to 80% in less than an hour @ 208 volts. I need about 10-25% for each leg of my commute.

Ok, to go into the longer story, 2 stations w/a J1772 handle each (and a 120 volt outlet under a metal door) were removed and replaced by 3 dual J1772 handle stations (for 6 J1772 handles) for use by EV valets. We can use the optional EV valets, if we want. We kinda need (and have) valet parking now as sometimes, the parking garage and lots have gotten too full. This is until a new building and parking lot goes online.

I don't know the current ratio now as I haven't counted those on our list recently and a few EVs/PHEVs have popped up who aren't using the self-serve EV stations anyway. I saw them use the valets.

No need to campaign. We had our first ever EV meeting w/facilities not long ago and again, none of us were complaining and that's when they told us about future plans and the EV valets. The valets have reduced contention of the non-valet stations significantly. If drop by the garage in the afternoon, sometimes there are open EV spots and unused handles. Also, if I watch the EV valet spots, it seems there are plenty of (valet) free handles and spots by say 3 pm.

So, in short, no problems that I can tell w/what we have. If we suddenly got double the # of EVs/PHEVs vs. what we have now, I could see a problem.

 

[nozferatu]

The Motor:

Everything about the motor is brilliant. A drive shaft runs through the motor so it can be lower to the ground. The motor is oil-cooled, like the Tesla, making it more thermally stable than only water cooling. It reaches maximum power at just 2000RPM and has a redline of 5500 RPM, meaning it has gobs of untapped potential.

You sure the RPM values at that low???? Motors usually spin much much faster than that.

 

[cwerdna]

To add to the EV/PHEV charging situation at my work (which again, is not bad at all), I noticed there are 5 (possibly more) spots painted as designed EV charging spots w/120 volt outlets, so those w/modest charging needs can use their car's supplied L1 EVSE.

 

[FutureFolly]

The Motor:

Everything about the motor is brilliant. A drive shaft runs through the motor so it can be lower to the ground. The motor is oil-cooled, like the Tesla, making it more thermally stable than only water cooling. It reaches maximum power at just 2000RPM and has a redline of 5500 RPM, meaning it has gobs of untapped potential.

You sure the RPM values at that low???? Motors usually spin much much faster than that.

It's an artificial redline. The car can't handle the speeds that a normal 10,000+ RPM redline would produce because of the low gear reduction ratio. I meant they could easily keep the power band flat longer than 2,000 RPM if they wanted to raise the power rating.

http://insideevs.com/2014-chevy-spark-ev-gets-epa-range-rating-of-82-miles-119-mpge-combined/
It's worth clicking on just to see Tony Williams go fanboy on him. Lol

I am the general director for Electric Drives and Electrification Systems Engineering at General Motors. I need to disabuse you of the mistaken notion that this motor has less than 400 ftlb of Torque. The Spark EV motor is designed and manufactured by GM. This motor makes 540 Nm (402 ftlbf) of Torque at stall and out to about 2000 rpm. This is not gear- multiplied axle torque, but actual motor shaft torque. The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two). This is a very low numerical reduction ratio, which has several great benefits – 1) Feels much better to drive. 3.18:1 is less than half of the reduction of all other EVs. This makes for extraordinarly low driveline inertia, less than 1/5 of the driveline inertia of the Nissan Leaf and 1/4 that of the Fiat 500 EV. Their cars feel like you are driving around in second gear all day long; ours feels like fourth gear. 2) Lower gear mesh, spinning losses, and lower high speed electromagnetic losses mean very high drive unit efficiency. The Spark EV efficiency from DC current to delivered Wheel torque is 85% averaged over the city driving schedule and 92% when averaged over the highway schedule. This is the highest in the industry, and that is one of the reasons why the Spark EV sets the benchmark for most efficient car.

 

[nozferatu]

The Motor:

Everything about the motor is brilliant. A drive shaft runs through the motor so it can be lower to the ground. The motor is oil-cooled, like the Tesla, making it more thermally stable than only water cooling. It reaches maximum power at just 2000RPM and has a redline of 5500 RPM, meaning it has gobs of untapped potential.

You sure the RPM values at that low???? Motors usually spin much much faster than that.

It's an artificial redline. The car can't handle the speeds that a normal 10,000+ RPM redline would produce because of the low gear reduction ratio. I meant they could easily keep the power band flat longer than 2,000 RPM if they wanted to raise the power rating.

http://insideevs.com/2014-chevy-spark-ev-gets-epa-range-rating-of-82-miles-119-mpge-combined/
It's worth clicking on just to see Tony Williams go fanboy on him. Lol

I am the general director for Electric Drives and Electrification Systems Engineering at General Motors. I need to disabuse you of the mistaken notion that this motor has less than 400 ftlb of Torque. The Spark EV motor is designed and manufactured by GM. This motor makes 540 Nm (402 ftlbf) of Torque at stall and out to about 2000 rpm. This is not gear- multiplied axle torque, but actual motor shaft torque. The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two). This is a very low numerical reduction ratio, which has several great benefits – 1) Feels much better to drive. 3.18:1 is less than half of the reduction of all other EVs. This makes for extraordinarly low driveline inertia, less than 1/5 of the driveline inertia of the Nissan Leaf and 1/4 that of the Fiat 500 EV. Their cars feel like you are driving around in second gear all day long; ours feels like fourth gear. 2) Lower gear mesh, spinning losses, and lower high speed electromagnetic losses mean very high drive unit efficiency. The Spark EV efficiency from DC current to delivered Wheel torque is 85% averaged over the city driving schedule and 92% when averaged over the highway schedule. This is the highest in the industry, and that is one of the reasons why the Spark EV sets the benchmark for most efficient car.

Indeed...lol...I just think he hates the Spark and Volt and GM. I'm no fan of GM but the Spark is a nice car.