RE: 3p? charging stations, cars, swapping packs.

["Coleman, Bruce" <Bruce.Coleman@am.sony.com>]

Lee Hart wrote:

"A dump charger means you have a large stationary pack of batteries on
charge, and a smaller pack in the vehicle. When you get back, you
connect the batteries in parallel, and the stationary pack very quickly
charges the vehicle batteries at some enormous current; 100's of amps.
If you pick the batteries and voltages right, the vehicle pack comes up
to 80% SOC quickly, but then is self-limited to avoid overcharging and
battery damage."


Would this be a good way to charge an EV from a home solar cell system?
Could I charge my small electric bike batteries from a larger set of 
batteries, (the smaller batteries won't explode or anything, will they? ) 

Bruce Coleman



-----Original Message-----
From: Lee Hart [mailto:leeahart@earthlink.net]
Sent: Thursday, May 31, 2001 8:46 AM
To: ev@listproc.sjsu.edu
Subject: Re: 3p? charging stations, cars, swapping packs.


Jeffrey Reed wrote:
> I have some enthusiastic but money strapped people
> urging me on to build an EV shop.

Sounds good for them; what's in it for you? :-)

Sadly, there are many, many examples of EV businesses that can't make a
profit because their customers expect too much for too little.

> My other project is a personal one - I deliver pizza
> and I want to use an EV to deliver in.

Sounds like you want either a fast-change battery pack, or a dump
charger. Or two EVs, and trade back and forth for alternate runs.

With a fast-change pack, one set of batteries is on charge while the
others are being use. Swap them when you get back. With a little
creativity, this could be accomplished very quickly.

A dump charger means you have a large stationary pack of batteries on
charge, and a smaller pack in the vehicle. When you get back, you
connect the batteries in parallel, and the stationary pack very quickly
charges the vehicle batteries at some enormous current; 100's of amps.
If you pick the batteries and voltages right, the vehicle pack comes up
to 80% SOC quickly, but then is self-limited to avoid overcharging and
battery damage.

For only 8 miles per trip, the vehicle's pack could be fairly small.
This is especially true if it is small vehicle like an NEV or Cushman
"meter maid" 3-wheeler. With specialty vehicles like this, it would be
an asset to have two of them anyway, just so you have a backup if one
needs repair.

Domino's Pizza did some work on special EVs for pizza delivery. You
might take a look at what they did.
-- 
Lee A. Hart                Ring the bells that still can ring
814 8th Ave. N.            Forget your perfect offering
Sartell, MN 56377 USA      There is a crack in everything
leeahart_at_earthlink.net  That's how the light gets in - Leonard Cohen