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Tesla will use solar panels and batteries at Supercharger stations to help supply this extra electricity

Tesla is looking to turn the electric vehicle (EV) industry upside down once again with a new system that could fully charge a Tesla vehicle in just five minutes. 

Tesla Chief Technology Officer JB Straubel recently said that the automaker is working on a charging system that would get drivers out of the Supercharger stations and back on the road with a full charge in just 5 minutes.

“It’s not going to happen in a year from now. It’s going to be hard. But I think we can get down to five to 10 minutes,” Straubel said.

Tesla plans to do this by making sure all parts of the charging process are communicating with one another so that the battery isn't negatively affected by such fast charging speeds. A battery can easily overheat at these speeds, but Tesla's Superchargers work differently from traditional charging methods.

Traditional charging consists of on-board chargers that take AC power from the wall socket and convert it to DC. From there, it can regulate the power given to the battery. 

The Superchargers, on the other hand, skips the use of the onboard charger and converts AC to DC outside the vehicle. The outside charger keeps an eye on battery voltage and temperature and changes rates of charging as needed to keep the battery safe. But in order for the outside charger to monitor these stats, it must communicate with other parts of the vehicle. 

Aside from potential battery issues, charging more quickly can take a toll on the grid and utilities. Tesla's current Superchargers deliver 120 kilowatts of electricity while most other charging systems -- such as General Motors' -- offers a maximum of 100 kilowatts. It's difficult to draw larger amounts of power from the grid without seeing costs rise significantly. 

Tesla plans to fix this by giving its Supercharger stations solar panels and batteries. The solar power would be stored in batteries and lessen the amount of electricity drawn from the grid. Also, the system could help utilities monitor major changes in the grid, and Tesla could charge them for this service -- hence keeping costs down. 

Other automakers have employed solar power for their EVs, too. For instance, General Motors (GM) announced a solar charging canopy called the Tracking Solar Tree, which moves with the sun and helps to charge GM's EVs. It's kept in Michigan, and is able to increase renewable energy production by about 25 percent due to its movable parts. In addition, the tree will produce up to 30,000-kilowatt hours per year and generate enough solar energy to charge six EVs daily.

Deploying charging tech that will allow drivers to charge their vehicles as quickly as it takes to fill up a tank of gas could significantly help push the adoption of Tesla EVs. Convenience and cost are two huge selling points, and it looks like Tesla has tackled both in this case. 

By the time Tesla rolls out the affordable version of the Model S, which is reportedly in the works, more people may consider buying the price-friendly vehicles and using its convenient tech. 

Tesla's Supercharger stations can charge a Model S battery halfway in just 20 minutes today. 

Just last month, Tesla unveiled a convenient alternative to waiting for a Model S to charge -- battery swapping. The idea behind battery swapping is to easily open the car chassis to pull the battery out and replace it with a fully charged one. This saves the driver from having to wait for their battery to charge before traveling.

Tesla is doing everything it can to get Model S' into the hands of customers, too, as it recently ramped up production to over 400 Model S' built per week.

Source: Technology Review

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Nor Really That Difficult
By Shadowself on 7/17/2013 2:22:58 PM , Rating: 4
Car batteries for electric vehicles are an optimized combination of battery cells in parallel and serial connections. When charging the internal resistance of all the cells in a series significantly slows the charging process due to losses and heat generation.

If a system were put into the car battery that could -- for fast charging -- switch all cells into purely parallel charging, then the internal resistance and heat generation of each cell can be treated independently, and they are much less. The charging could be done much, much faster. (Think of a Marx Generator with batteries instead of capacitors.) Charging a single cell (which is effectively what you're doing if you charge them all in parallel) can be done much faster than charging 20 cells in a series.

The downside would be the added complexity (with associated maintenance concerns), implementation costs and weight. Additionally, total currents would be much higher, but voltages would be much lower.

Also the charging stations would likely have to be a combination of batteries and super capacitors to handled the currents necessary.

It can be done. It's not rocket science.

RE: Nor Really That Difficult
By Pneumothorax on 7/17/2013 2:37:34 PM , Rating: 1
Yup, I fly RC helicopters with 12S lipo packs that top out at 50 volts at full charge. My 2 1300 watt chargers can charge the 12 cells in parallel at 8C which is about about 10 minutes for a full charge. It does pull a little over 20 Amps from the wall though and sometimes trips the circuit breaker lol. I shudder to think how much harder it would be to charge the batteries in series...

One negative of such rapid charging is I find I lose battery capacity from faster aging of my packs vs if I charge at a more sedate 2C rating of around 30 minutes per charge. I'm not sure if the batteries that Tesla uses will be immune from faster aging from faster charge rates.

RE: Nor Really That Difficult
By Mint on 7/17/2013 3:12:13 PM , Rating: 2
I didn't know 8C charging was doable with today's cells. Thanks for the post.

lipo is not known for cycle life, AFAIK, so I would expect that degradation is a bit faster than in the cells Tesla is using.

RE: Nor Really That Difficult
By flyingpants1 on 7/18/2013 12:13:31 AM , Rating: 2
The Tesla batteries are not "immune" from fast-charge aging, but it may be less of an issue than we think. I do not know exactly what cells Tesla is using off-hand. I have heard lifespans ranging anywhere from 300-1500 cycles for different lithium ion cells. The Model S batteries are under warranty for 125,000 miles, which means 416 full recharges over the life of the car (and they are expecting 70% capacity remaining in the pack at the end of the warranty period at which point the batteries can be repurposed for solar or whatever). So they need 416 recharges to make the warranty, and it may be possible to reach double that. This is also without taking weather into account.

But remember that most people will almost never fully discharge the battery or even need to use a supercharger, because people simply do not drive that much in a day. Recharging to 80% significantly increases the life of the pack.

At least some of the cell degradation from faster charging is due to heat, the Model S battery pack mitigates this with a cooling system.

RE: Nor Really That Difficult
By Mint on 7/18/2013 11:56:33 AM , Rating: 4
There's a lot of proprietary knowledge that Tesla has about batteries and how best to use them. Even if you see 80% charge, you have no idea what's going on internally. There can be wear leveling or there could be wear concentration. The latter could be useful if it's better to discharge one cell group 1000 times instead of ten cell groups 100 times, and you could refurbish the pack by replacing just that one cell group.

Some data has been collected for the Tesla Roadster, and battery life looks quite promising:
100k miles with only 15-20% loss of range is pretty good.

RE: Nor Really That Difficult
By flyingpants1 on 7/19/2013 12:50:01 AM , Rating: 2
Right, the smarter you are about your pack, the better you can do wear-levelling, the longer you can make the pack last..

Plus no doubt Tesla is working with Panasonic to find the best possible chemistry for these things, and bringing down the cost of the actual pack (besides the cells).. The current technology will be fine for decades to come, all we need is incremental improvements and price drops..

RE: Nor Really That Difficult
By invidious on 7/17/2013 2:42:05 PM , Rating: 3
It can be done. It's not rocket science.
Electrical engineering is more complex than rocket science.

RE: Nor Really That Difficult
By invidious on 7/17/2013 2:43:06 PM , Rating: 2
But yes it certainly can be done.

RE: Nor Really That Difficult
By ChronoReverse on 7/17/2013 3:06:49 PM , Rating: 2
Is it? Rocket engineering has to encompass electrical engineering.

Not that I'm saying EE isn't complex (I have a bachelor's in EECE so I have my toe in the waters at least) but it seems unusual to object to a euphemism on that grounds.

RE: Nor Really That Difficult
By PaFromFL on 7/18/2013 9:00:09 AM , Rating: 2
Degree of difficulty = (# of physicists)/(# of engineers).

Rocket science pushes the envelopes of material science, aerodynamics, magnetohydrodynamics, thermodynamics, mechanical engineering, radiation hardening of electronic devices, etc. Electrical engineering typically focuses on the application of Maxwell's (linear) equations, linearized device models, linear digital signal processing algorithms, and optimization of linear systems with a quadratic (power) performance metric and Gaussian statistics.

Vehicle battery technology needs some more scientific breakthroughs to compete with liquid fuels. Battery development should be more like rocket science than engineering.

RE: Nor Really That Difficult
By alpha754293 on 7/18/2013 10:32:01 AM , Rating: 2
No...I'm pretty sure that rocket science is still more complex than electrical engineering.

People seem to have a pretty good grasp on what's going on with electrical engineering. Things might get smaller, and so you start running into the physical limitations of the hardware, but at that point, that's more physics than EE.

Rocket science on the other hand - ask any rocketry expert about hybrid rocket motors and how to model, build, test, develop, engineer hybrid rocket motors. It's not like you can just stick a "how-is-it-doing"-o-meter into the nozzle without it melting or being vaporized instantly or near-instantly.

Course, for someone to say that, it's probably an EE that's never built or worked on a rocket before. ;o) (Or a related field like CFD)

RE: Nor Really That Difficult
By JKflipflop98 on 7/18/2013 7:36:42 PM , Rating: 3
It's not a contest. They both have envelopes to push. Neither one is easier nor harder than the other.

RE: Nor Really That Difficult
By Slyne on 7/17/2013 2:51:32 PM , Rating: 2
It can be done. It's not rocket science.

I see what you did there

RE: Nor Really That Difficult
By Mint on 7/17/2013 3:24:21 PM , Rating: 3
You should stick to rocket science and leave this for the EEs :P

Charging a single cell (which is effectively what you're doing if you charge them all in parallel) can be done much faster than charging 20 cells in a series.
No, that's not right at all. Say you have cells that are 3.6V nominal, 1Ah, 0.1 ohm internal resistance.

Ten in series charged at 10C (i.e. ~6 minutes) needs 46V, 10A. Ten in parallel needs 4.6V, 100A. Same total power, same total heat generated overcoming internal resistance.

Fast charging needs too things: adequate power, and a cell chemistry/structure that can take it without degrading. Nanostructured electrodes are often used in research batteries capable of high C rates (discharging and charging).

RE: Nor Really That Difficult
By Spuke on 7/17/2013 3:59:25 PM , Rating: 2
Ten in series charged at 10C (i.e. ~6 minutes) needs 46V, 10A. Ten in parallel needs 4.6V, 100A. Same total power, same total heat generated overcoming internal resistance.

RE: Nor Really That Difficult
By Pneumothorax on 7/17/2013 4:11:05 PM , Rating: 2
You're right, the wattage is the same, even the argument could be made that you can use much thinner charging cables when charging 10A @ 46V vs. 100A @ 4.6V
But, it's easier to charge these large muti-cell series packs in EV's in parallel as when charging in series lithium packs at higher rates results in imbalanced cells that have to be balanced before you can max out the voltage as lithium batteries are very sensitive to overcharging which is much more likely when they're charged in series at very high rates.

RE: Nor Really That Difficult
By Mint on 7/18/2013 11:44:11 AM , Rating: 2
That's not the argument Shadowself was making.

You are right that individual cell control is important in getting this done safely and with minimal cell degradation. I was just debunking his theories about internal resistance.

But there are many different solutions, and it doesn't have to strictly series or parallel. You can have a combination, you can shunt current or create an artificial voltage drop across faster-filling cells, you can have DC-DC converters to have multiple voltages, relays disconnecting some cells or changing which charging group a cell belongs to, etc.

RE: Nor Really That Difficult
By someguy743 on 7/17/2013 5:20:00 PM , Rating: 2
I bet it is an electrical engineer's dream to be working at Tesla these days designing world changing technologies like they are doing.

I bet it's also exciting to be a battery scientist or nanotech specialist working on these new battery technologies.

“And I don't know why [Apple is] acting like it’s superior. I don't even get it. What are they trying to say?” -- Bill Gates on the Mac ads

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