Your needs may differ but, for me, unequivocally the charge time is more
important. Consider at least 10:1 for charge:discharge and perhaps
even 100:1 as long as the battery can handle one or two minute bursts at
high current.
I want to pull into a charge station, get a full charge in 5 minutes and
drive for a a few hours. At 30:1 I could get 2.5 hours of driving for 5
minutes of charging. This kind of charge time would truly make a cross
country trip practical.
Of course, if you're on the drag strip, you won't be interested in 30:1
;)
Peri
------ Original Message ------
From: "Ben Goren via EV" <ev@lists.evdl.org>
To: "Cor van de Water" <cwa...@proxim.com>; "Electric Vehicle Discussion
List" <ev@lists.evdl.org>
Sent: 07-Apr-15 4:50:26 PM
Subject: Re: [EVDL] Aluminum battery from Stanford
On Apr 7, 2015, at 4:25 PM, Cor van de Water via EV <ev@lists.evdl.org>
wrote:
Time will tell if we soon will have a 1-minute rechargeable
battery....
...and a 1-minute *dischargeable* battery. That's probably an even
bigger deal than the charge time.
Right now, charging times seem to be limited on all sorts of things
other than battery chemistry -- at least, in the automotive world. I
suppose cell phones may well be limited by chemistry.
From what I can tell, typical batteries in today's EVs have discharge
rates in the single-digit C values, which limits their power output to
about the same as their ICE equivalents. But this is an order of
magnitude more than that, and twice what even A123 offers. If these're
price-competitive with today's batteries -- and, of course, if all
these numbers actually hold up -- then we're looking at econoboxes with
batteries that would make Weyland and Garlits and the rest drool.
Of course, the econoboxes wouldn't get the motors and controllers that
could keep up with the batteries...but...well, for example, a battery
like this might well be able to replace mechanical brakes by actually
being able to absorb all the energy from an hard stop with regen. That
would eliminate yet another component and its weight and complexity.
I'm sure all sorts of other possibilities present themselves if these
power numbers are real.
Like...mechanical recharging. Pull into the "gas" station with the
wheels on a dyno. (Or, more realistically, something that coupled to
the wheels / drivetrain without relying on the friction of rubber.)
Line current (or battery banks or whatever) power the dyno; the car
turns on full regen. If the car *did* have a dragster-capable motor /
controller / whatever, you could thereby pump that megawatt into the
batteries and, in three minutes, put 50 kWh into them. Yes, there'd be
efficiency losses...but electricity is dirt cheap compared with
gasoline, so people likely wouldn't care.
b&
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