FutureFolly
Well-known member
- Joined
- Feb 27, 2014
- Messages
- 141
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.
-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.