I just found this news item: http://www.streetinsider.com/Analyst+Comments/Tesla+(TSLA)+to+Develop+Hybrid+Battery+Packs+that+Could+Increase+Range+40%25+-+Analyst/8689599.html
Does anybody know anything more about this and the technology behind it?
Maybe this link works better: http://goo.gl/E78kyT
And here are the links to the two patents mentioned:
In another thread (I can't find it!) several months ago there was discussion of battery pack design for increased range. Since various lithium batteries provide different types of performance, I suggested that a hybrid arrangement would be a way to increase range without technological break through.
Lithium-ion batteries are slow to charge but fast in their discharge, providing quickly available energy for acceleration, starts and stops, etc. Other Lithium batteries (there are a number of designs) are quick to charge but slow to discharge, making energy available more slowly. These other lithium based batteries would be ideal for maintaining steady driving after accelerating to a desired speed, eg cruise control.
The current management systems of hybrid cars would seem to be an ideal method for switching between the two battery packs for optimal energy use and extended range. The Tesla battery swap system would be ideal for upgrading existing Model S battery packs. The Model E and the 'new' Model S coming in 2-3 years could be outfitted during production. There would be no need to change the converter/motor arrangement.
From the very beginning, Elon has observed that the battery pack was designed for easy upgrade . . . and for use of whatever new energy source that might come along.
i'm glad to hear Tesla is leading the pack with new battery technology will make future car batteries more powerful, lighter and more compact, and hopefully also more affordable before our warranty expires... but will Tesla price the new batteries to encourage existing customers to buy a new replacement battery or buy a new Tesla?
The hybrid battery idea is not exactly new, but I hope tesla can perfect it:
"Small lithium-ion packs could provide short power bursts for city driving and acceleration from low speeds, while lower-cost, higher-density zinc-air batteries would furnish the power for long-distance cruising, giving EVs the range they now lack at a more affordable price."
A really interesting article, thanks Pacey.
To be more precise, a hybrid battery pack has been patented by Tesla. Tesla patents many ideas that don't necessarily make it to the production floor, just like most companies do.
Sounds like what many were thinking would be the "Surprise" a few months ago, a metal-air booster in the "microwave" frunk spot. But TM shot that down: no wiring and cooling was not workable.
Most such patents are never implemented, and may be anti-competitive moves. Hard to say.
The hybrid battery idea and associated patents is awesome and the fact the the cars are designed such that the "energy storage module" can be swapped out as new technology comes to market is just pure genius. Jackhub sees this clearly from the first post above. Recently I came across an article on graphene supercapacitors (see link below) that just may further extend the range of an electric car by capturing more of the regen energy, as they can be fully recharged in 16 seconds. When this comes into play it will become possible to drastically reduce the size of the LI ion battery pack and not loose any range, the Supercapacitor can recharge the LI ion pack while on the go. Things are changing rapidly. Who knows what combination battery/supercapacitor hybrid "energy modules" will come out of the giga factory in the next three years. Looking forward to my next Tesla vehicle.
Then of course (once the energy density improves for the supercapacitor) eventually there will be no need for the LI ion battery portion at all.
Supercaps will only be useful in the Tesla for regenerative braking, because they are still 3-4x as heavy per kWh... so they can't be used for any significant portion of the overall energy storage.
As an adjunct, they might be useful for allowing more rapid accumulation of charge from the motors as regen occurs. I'm not sure if the current motors are capable of producing more current than they already do, though. I notice the little green "charging" indicator tops out at 60kW, but the dial seems to go higher than this. Of course this is just a display configuration, and doesn't say anything about the actual design specs of the motor.
My guess is they designed the motor to be capable of producing just as much regeneration current as the battery can handle. The motor is too central of a component for it to be designed with future breakthrough technology in mind.
So, for supercaps to be useful in a model S, it would require that a lot of the other hardware be redesigned and replaced. They're more likely to be found in the economy version to come out in 2017.
Good to be thinking in this direction but like some have said, the modular battery pack idea has been around for a long time and also used. Electric buses in Singapore in 1990ies had zinc air and lead acid hybrid batteries. Zinc air for cheap storage and lead acid (compared to first rechargeable zinc air batteries were less soft in terms of voltage sag) for higher current draw voltage stability. Today, this would be a zinc air and li ion hybrid for instance.
Also, the approach with lots and lots of small consumer grade cells, like in a Tesla, also isn't as novel as some think. The first Prius had a battery pack comprised in same way, but with small NiMh cells.
Tesla isn't necessarily first in all things but does a great, and if one looks at the market, by far the best job of selecting approaches and bringing them to actual use.
The graphene supercaps can be charged that fast -- given an adequate current. The source and connection must be up to the job, and to load, say, 50kWh in 16 seconds would require about a 10 MW feed. Think lightning strike.
Yow! I was just imagining a 16-second long lightning hit. I'd pay to watch!
If it was sixteen seconds long, how would you know when the thunder was due to arrive?
If you were close enough to watch the car, it would be virtually instantaneous. A LOOONNGGG thunderclap.
Doc Brown: "1.21 gigawatts!"
I think those were jigawatts, weren't they?