Posted by Jim Wilkins on May 20, 2009, 12:43 am
On May 19, 9:42am, nob...@xmission.com (Scott) wrote:
> On Mon, 18 May 2009 19:02:56 -0700 (PDT), in alt.energy.homepower, Jim
> >This is a good example of what EV designers have available.
> >http://www.a123systems.com/technology/power
> They make some impressive claims. Do you know if they have any products at
> market yet?
I work on electric vehicle R&D and am severely limited in what I can
mention.
These 18650 Lithiums which have been around for several years charge
in 2-1/2 hours.
http://www.valence.com/sites/all/themes/valence/pdfs/18650e%20Cells%20Data%=
20Sheet.pdf
jsw
Posted by residualselfimage1999 on May 20, 2009, 2:25 am
On May 19, 9:42am, nob...@xmission.com (Scott) wrote:
> On Mon, 18 May 2009 19:02:56 -0700 (PDT), in alt.energy.homepower, Jim
> >This is a good example of what EV designers have available.
> >http://www.a123systems.com/technology/power
> They make some impressive claims. Do you know if they have any products at
> market yet?
The few reports that I have read about A123 System over the last
two years or so suggest to me that A123 System has chronic
financing and mass production challenges. While they have been
able to produce enough Lithium Ion battery packs to supply
Hymotion's Prius Plug in conversion kits - A123 Systems
was never able to secure large order contracts due to price
point.
IIRC A123 System is using a type of nanotechnology that creates
a greater surface area (sort of like the dimpling of a golf ball outer
shell) which greatly enhances the battery's power but also makes
it more difficult to mass produce. This type of industrial
engineering
challenge is solved by a team of engineers from a variety of
disciplines working together. - the reports that I have read about
A123 makes me wonder if they have assembled the *right* team.
Posted by Jim Wilkins on May 20, 2009, 11:16 am
On May 19, 10:25pm, residualselfimage1...@gmail.com wrote:
>...This type of industrial engineering
> challenge is solved by a team of engineers from a variety of
> disciplines working together. - the reports that I have read about
> A123 makes me wonder if they have assembled the *right* team.
Even when you are on such a team it can be very hard to know if the
stickiest problem could be solved by a different engineer or if it has
to wait for a development in other areas, such as better analytical
instruments. When I learned chemistry very thin layers and especially
surface reactions in a liquid were almost impossible to study. They
are critical to understanding batteries.
In a few cases I built that instrument, for example one that gave a
scope display of the dielectric absorption charge leaking out of an
insulator after a voltage change. The goal was to find wire and reed
relay insulation that allowed the automated semiconductor wafer test
machine we were building to measure femtoAmps on a 100V bias, quickly.
And it did work as promised, but we announced it just as the economy
collapsed in the mid 1980's and capital equipment purchases
disappeared. In one week a large backlog of orders became half a dozen
unsold $00,000+ machines. Soon the company closed.
jsw
Posted by clare on May 21, 2009, 2:38 am
On Mon, 18 May 2009 19:02:56 -0700 (PDT), Jim Wilkins
>On May 18, 9:29 pm, nob...@xmission.com (Scott) wrote:
>>
>> A more interesting question is how quickly the EV's battery bank can accept
>> a full charge. The lead-acid batteries with which I'm familiar have an
>> upper limit on the charge current they can accept without damage, setting an
>> absolute minimum recharge time for any given state of discharge regardless
>> of how much power is available to the charge controller.
>This is a good example of what EV designers have available.
>http://www.a123systems.com/technology/power
>jsw
Look at the Genesis EP line of lead acid batteries. They can take a
charge almost as quick as they can put it out.
Posted by Eeyore on May 19, 2009, 1:43 pm
Scott wrote:
> >Yes I gave a calculation for a recharge time from a standard NEMA 15A outlet.
For a practical
> >recharging time you'd need to better that by at least 5 times. Running at
240V would reduce the
> >current by 2, so you could use say a 240V, 38A circuit single phase for an ~
6 hour recharge.
> Nobody would use a convenience outlet to charge an EV, they're for radios
> and reading lamps. We commonly have dedicated 30A and 50A 240V outlets, 60A
> is easy, and 100A can be done (possibly more, but I've verified the
> availability of 100A plugs and sockets) delivering 50kWh in just over two
> hours. From standard single-phase residential service.
> Is 38A the most you can get in a British flat?
A standard supply would be 60A for a flat or small house and 100A for larger @
240V of course.
> A more interesting question is how quickly the EV's battery bank can accept
> a full charge. The lead-acid batteries with which I'm familiar have an
> upper limit on the charge current they can accept without damage, setting an
> absolute minimum recharge time for any given state of discharge regardless
> of how much power is available to the charge controller.
That's a limitation of lead-acid technology of course. Fast recharge technology
is gradually coming
on line with Li-ions like those from A123 system.
> >In practice I've never seen one although you could invent one if you were
sufficiently daft.
> Didn't have to, the Japanese did it a long time ago.
How did they manage that ?
Graham
> >This is a good example of what EV designers have available.
> >http://www.a123systems.com/technology/power
> They make some impressive claims. Do you know if they have any products at
> market yet?