There are many more hurdles than price, energy density, and recharge-cycle limit for batteries.
It's fantastic that 3 of the following 10 items are improving by leaps and bounds. But if all 10 of them don't get better together, the Internal combustion engine will still be making the Tesla Model S look like a rich person's toy.
1. How much does it weigh? If it weighs too much, maxing out on all the other attributes doesn't matter.
2. Does it harm anyone if a person is in close proximity when the battery is crushed, shot, or wrecked in any way?
3. Does the lifespan decrease with prolonged usage in -40F or 150F weather? Does vibration break it?
4. How long does it take to fill up assuming unlimited power resources?
5. How long does it take to charge given roadside assistance resources?
6. How many charge-discharge cycles?
7. If you leave the car in a garage for 6 months is the battery bricked? What is the discharge rate when left unattended?
8. Cost of replacing the battery.
9. Toxic chemicals or rare metals to make disposing the battery expensive or bad for landfills?
10. How quickly can you discharge the battery without it melting or exploding?
The success of battery powered cars doesn't have to hinge on any of these items if Gasoline prices were to triple while the cost of batteries stay the same. Then battery powered cars will immediately dominate, and solar power charging stations in your roof will be the only economical choice.
1. Improving dramatically with improvements in energy-density. The weight of a battery-pack capable of >140miles plus electric motor weighs less than the gasoline engine it replaces, not counting the weight of a full tank. (this is based on battery packs available commercially from several years ago - a friend built an electric 911 with Kokam cells with these specs).
2. Conventional Li-Ion (cobalt) cells are definitely dangerous, best stick with NiMH or LiFePO4 to avoid that problem.
3. Those temps are a bit extreme... arguably small markets there.
4. Newer battery tech is reducing the charging time massively... I've read more than a few quotes of ~5 minutes for an 80% charge (diminishing rates beyond that). Example (granted, not near market ready): http://www.extremetech.com/extreme/134635-scientists-develop...
5. That's a much bigger problem... towtrucks would have to have a considerable powerplant on-board for this.
7. Well designed controls should prevent this (shutting down the on-board systems when batteries get below a certain point, rather than taking them past the point of no return).
8. This is coming down fast enough that by the time you have to replace the battery pack, it'll be a non-issue.
9. Again, avoid cobalt-based Li-Ion batteries, and this is not an issue. LiFePO4 batteries are an enormous improvement on this problem - less toxic than the lead cells in your car now.
10. Yet another massive improvement that's a side-effect of the lowered internal resistance in modern batteries. This goes hand-in-hand with the improvements in charge-rates (lower internal resistance means less heat from current, whether going in or coming out of the cells).
> 3. Those temps are a bit extreme... arguably small markets there.
Not really. The high temp is actually on the low side - a parked car in sunlight in the summer can reach 190 degrees!
-40 is a bit extreme for some parts of the world, but in other places it's not unusual. Perhaps not for the entire winter, but certainly as a daily low.
That's the interior of the car, which is effectively a greenhouse.
You don't put the battery packs on the inside of the car any more than you'd put the fuel tank on the inside. Typical placements are underneath the vehicle, arguably the coolest area possible. This is where the Tesla model S places the pack, as does the Fisker Karma, and this is also where the old ('97-'03) RAV4 EV placed the NiMH pack.
It's funny. All the things you mentioned (even disposal!) are essentially a function of pack architecture. Elon Musk has consistently stated that Tesla is a hardcore engineering and technology company, with the R&D subject being... pack architecture. Just look at their patents: http://www.faqs.org/patents/assignee/tesla-motors-inc/
Tesla Motor's solutions to these problems has been:
* Many small cells. Small cells are easier to cool and you get tighter temperature uniformity.
* Active temperature control. Energy is cheap compared to the capital cost of the cells. Active temperature management earns back its own range penalty. It enables the widest choice of cell chemistry.
* Physically isolate the cells to prevent cascading failures.
* Robust battery box rigidizes the vehicle's frame.
* "Skateboard" architecture not unlike GM's Autonomy concept / Hy-Wire prototype (except no fuel cells). You get a low center-of-gravity, battery swap capability, and an aerodynamic belly for free. Pack is easy to access using a standard vehicle lift. Compatible with novel business models, like "buy the car, lease the battery".
* Fine-granularity diagnostics and charge/discharge control. Improves pack reliability, longevity, and performance.
5. How long does it take to charge given roadside assistance resources?
Or will the owner just call AAA for a tow or flat-bed to a charging station?
7. If you leave the car in a garage for 6 months is the battery bricked? What is the discharge rate when left unattended?
Unattended and not plugged in? Else, trickle charge with manual or perhaps robotic plug-in.
9. Toxic chemicals or rare metals to make disposing the battery expensive or bad for landfills?
Lead-acid batteries are generally recycled now, why not newer batteries?
I would expect a battery replacement to be handled as
an exchange, by specialists.
10. How quickly can you discharge the battery without it melting or exploding?
How much acceleration can the tires handle? Crashes were mentioned in item 2.
More about available energy than lifespan, but here's a "tale of woe"
from a test driver in colder weather. I am surprised that the writer
equates the effects of 10F (-12C) weather on battery chemistry
with someone siphoning fuel from the tank, but so it goes.
I have seen hotels in cold climates (Finland) provide electrical
receptacles for block heaters for IC engined vehicles - which might
be adequate for a slow charge, or at least for maintaining a better
working temperature for a battery pack - too bad the writer didn't
have access to something like that.
My takeaway is that colder regions will need denser charging station
networks to serve long-distance travelers, and that all-electric
vehicles will be less popular for long-range multi-charge trips in
colder climates, but still good for daily commutes and any
"out-and-back" trips where the vehicle can be charged at the
destination while the travelers are doing something else.
(meal, meeting, entertainment, overnight stay, whatever).
That really depends on the local climate. Many locations will see temperatures below 0F and above 100F in the same year, and hotter weather can result in much higher temperatures near the road surface than measured by weather stations.
Next time, on a hottest day in the year, put your hand on the roof of your car, after 5 minutes your hand will be cooked like an overdone steak. Combine this with the fact that the driver may be racing to work on the hottest day, while running the AC on full. And 150F is something that happens to the battery every day for a month in many parts of America. And the battery has to handle spike temperatures up to 200F. Racing the car up a hill in the Southern texas sun? The Internal combustion engine can take it no problem because it's made of metal and plastics that can survive 200F. The battery maybe not.
It's fantastic that 3 of the following 10 items are improving by leaps and bounds. But if all 10 of them don't get better together, the Internal combustion engine will still be making the Tesla Model S look like a rich person's toy.
1. How much does it weigh? If it weighs too much, maxing out on all the other attributes doesn't matter.
2. Does it harm anyone if a person is in close proximity when the battery is crushed, shot, or wrecked in any way?
3. Does the lifespan decrease with prolonged usage in -40F or 150F weather? Does vibration break it?
4. How long does it take to fill up assuming unlimited power resources?
5. How long does it take to charge given roadside assistance resources?
6. How many charge-discharge cycles?
7. If you leave the car in a garage for 6 months is the battery bricked? What is the discharge rate when left unattended?
8. Cost of replacing the battery.
9. Toxic chemicals or rare metals to make disposing the battery expensive or bad for landfills?
10. How quickly can you discharge the battery without it melting or exploding?
The success of battery powered cars doesn't have to hinge on any of these items if Gasoline prices were to triple while the cost of batteries stay the same. Then battery powered cars will immediately dominate, and solar power charging stations in your roof will be the only economical choice.