New Li-Ion Batteries Charge 70 Percent in 2 Minutes, Last for 20 Years

[meyersnole]

Now this is the kind of break through that is needed to make the electric car take off!

 

http://gizmodo.com/new-li-ion-batteries-charge-70-percent-in-2-minutes-la-1645721894

 

Technology that could go into production by 2016 and have cars that can charge in 15 minutes? Yes please.

[murphy]

That is going to require a really big charger with huge cables to handle 100 amps or more.

[Russael]

This will only be practical for low capacity battery packs (cell phones, laptops, etc).  There is NO WAY to charge a huge pack that fast without a massive supply line.  There was a thread about fast charging cars and the supply that would be needed to charge packs in 15 minutes.

 

Example:  Our pack is 7.6kwh, but we are only able to charge about 6kwh out of it.  At 240v to charge 6kwh in 1 hour would require about 25A of current, not including losses, which isn't too bad.  For 15 minutes, 100A.  The service to my entire house is 100A at 240v.  So for even small packs like ours to charge in 15 minutes requires service that is incredibly substantial and impractical for residential service.  I suppose they could have commercial electric fuel stations like the Tesla superchargers peppered around, but each one would need a substation behind it to handle that kind of load if it had multiple connectors.

 

A Tesla S with the 85kwh pack... heh.  240v for say 80kw to charge in 1 hour would require 333A.  For 15 minutes, 1,333A.  If you increased to say, 960 volts, then you're back to 333A for 15 minutes.

[meyersnole]

Not even close to my area of expertise, but just as the battery has seen major progress in efficiency over the past decade due to focus, is it not also logical to assume that technical issues/limitations in transmission will also be overcome as needs arise?

 

I have spent a grand total of about 10 minutes with google to discover that there is already a great need to improve the world's capacity for electric transmission. China is deploying a more efficient transmission infrastructure with costlier materials to handle their growth.

 

I agree with the above that the really fast charging would be limited to a commercial offering, but again I think this makes it more viable. If the energy (Exxon Mobile, et al) companies have somewhere to go they are less likely to fight it if they can turn it into an opportunity. Even at 15 minutes this model has issues... but just happy to see that there is progress being made in battery technology.

 

The longevity of the new battery is probably more important to acceptance than charging speed (in my opinion), the speed is a nice bonus though. Still have many issues, scarcity of resources, weight, bulk, heat, ...

 

This battery technology has much promise beyond cars though... for example a better battery could also be paired with home solar to move homes off the grid. These types of applications make me think that deployment will face much opposition. Cynical, I know.  

[HotLap]

Thanks Meyersnole for sharing, great news indeed and while the transmission side will still be the limiting factor, even if we could use this technology to speed up the charging times by say 10% - 20% that's still an improvement and now that there will be (hopefully) a battery that can take such a quick charge, folks will start being more creative around the transmission side of things...how about dual 220v charge ports, would that be a potential strategy?  Another huge improvement is the longevity of the batteries (again if this new battery pans out), I would potentially look to invest in a battery pack with this longevity for my home solar and be able to get off the grid...a ways away perhaps, but good to see progress being made for sure!!

[Kybuck]

Not even close to my area of expertise, but just as the battery has seen major progress in efficiency over the past decade due to focus, is it not also logical to assume that technical issues/limitations in transmission will also be overcome as needs arise?

 

Compared to the ~century of research in power transmission, battery technology for electronics, etc. is relatively in its infancy still.  There is a potential for small improvements in transmission, but not for a complete game changer.  You could get around the need for larger wiring for the amperage by stepping up to a higher voltage, but that still won't get around the overall power transmission limitations.  

 

how about dual 220v charge ports, would that be a potential strategy? 

 

It would allow for lower amperage per charger, but would still be the same total load and would in any way help the infrastructure limitations.  Power companies prefer consistent loads, not 15 minute ~100 Amp spikes.

 

The only way I'd ever see this working for a car is if you have a separate capacitor / quick discharge battery (in a garage?) that you charge at normal rates throughout the day, and then it quickly discharges to charge the car quicker than the grid can support.   

Edited October 18, 2014 at 08:16 PM by Kybuck

[Russael]

The only way I'd ever see this working for a car is if you have a separate capacitor / quick discharge battery (in a garage?) that you charge at normal rates throughout the day, and then it quickly discharges to charge the car quicker than the grid can support.   

 

Interesting thought.  But then you're stuck with the problem of getting that energy in to the car at a high rate of speed.  It takes the sudden high load off of the grid, but you still have a delivery problem.

 

If you had a storage device in the garage that could store around 115kw of energy, you could charge that device from the grid at 240v at 20A over the course of 24 hours.  That's reasonable.  It'd be even better if you could use it as a backup battery of sorts for your home in case of commercial power failure.

 

Is there something in the national electric code that has any sort of limitation on voltage for a residence?  I don't know of any homes built with greater than 240v service.  Commercial services can go significantly higher than that.  The only way to get that power in to a vehicle at a high rate of speed without cables that are as thick as our thumbs (per WIRE, that is) is by increasing the voltage to something very high.  In order to charge a Tesla S in an hour is by using 480v at 167a using their superchargers.

 

70% over the course of 2 minutes is absurd.  Say you wanted to do this for a small battery, say a 11.1v laptop battery with a capacity of 6600mah (6.6Ah), or about 73.26 watt hours (.007326 kwh).  Say we charge it with 19.5v at 5A, a 97.5 watt supply.  Assuming no losses, it would take about 45 minutes for a full charge with constant current.  70% of 73.26 is 51.282 watts.  To deliver 51.282 watts at 19.5v over the course of 2 minutes would require 1538.46 watts, or 78.9A for those 2 minutes.  From a 120v wall source, 12.8A... more than a vacuum cleaner.  It is unimaginable what would be needed for a vehicle.

 

I probably screwed up the math, but it looks correct to me.  :)

[Dan's Energi]

Is there something in the national electric code that has any sort of limitation on voltage for a residence?  I don't know of any homes built with greater than 240v service.  Commercial services can go significantly higher than that.  

Some woodworkers have 3-phase run to their garage's.

[Russael]

That's still 240v though.  I believe my father had 240 3 phase run to his residence when he ran an enormous air compressor.  But does anybody have 480 run to a residence?

[Dan's Energi]

That's still 240v though.  I believe my father had 240 3 phase run to his residence when he ran an enormous air compressor.  But does anybody have 480 run to a residence?

I think you can get 240V though two legs but they were getting 400V through the 3.