I believe batteries, and Li-ion as well as future designs will not degrade
much for a decade and more when properly managed. Understand that 'Lithium
batteries" covers a large and disparate group of designs. So, any comment
can be quibbled over.
What is known now, a loss of 85% would probably be accompanied by physical
and chemical damage that might render them unreliable at greater loss. But
certainly Li-ion if managed well could be useful down to 30% SOC.
The rub here is "well managed." Proper management will depend on the exact
electrode and electrolyte chemistry, the construction of the cell,
temperature of operation and storage, particularly at high SOC%. and so on.
Anything we say is dependent on a host of variables. I think the body of
knowledge will grow and all these difficulties will drop in significance.
You did not say in what application the degradation to 70% SOC would occur
but safe to assume you meant in cars. Tesla already committed to creating
rid based applications for "degraded" batteries. Their belief is that
stationary applications are far easier on the cells than mobile and
automotive apps. Allowing us to believe there is a very good chance that
car batteries will likely have a second life.
Does anyone know how low the capacity of a battery can fall before it is no
useful, and how long will that take? At least 50%, probably more. 15% is
too low for current technologies.
For example, can the capacity shrink down to 15% SOC and still provide
useful power, how long would that take? Depends.
It will continue to improve.
On Fri, Sep 23, 2016 at 12:32 AM, Larry Gales via EV <email@example.com>
> Most scenarios assume that Lithium batteries for EVs should be replaced
> when they degrade to 70-80% of their initial capacities, after which they
> might serve as storage batteries for the grid, or a house. Does anyone
> know how low the capacity of a battery can fall before it is no longer
> useful, and how long will that take? For example, can the capacity shrink
> down to 15% and still provide useful power, and how long would that take?
> Thanks, Larry
> Larry Gales
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> Read EVAngel's EV News at http://evdl.org/evln/
> Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/
To invent, you need a good imagination and a pile of junk.
Thomas A. Edison
A public-opinion poll is no substitute for thought.
Michael E. Ross
(919) 585-6737 Land
(919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Mobile and
-------------- next part --------------
An HTML attachment was scrubbed...
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)