Article 48 (42 more) in sci.engr.mech:
From: tylerh@cco.caltech.edu (Tyler R. Holcomb)


Subject: Battery technology (from EV mailing list)
Message-ID: <1992Jun24.003555.16419@cco.caltech.edu>
Summary: battery technolgy for EVs
Keywords: batteries EV mailing list
Sender: news@cco.caltech.edu
Nntp-Posting-Host: globie
Organization: California Institute of Technology, Pasadena
Date: Wed, 24 Jun 1992 00:35:55 GMT
Lines: 54

This appears recently on the S. Cal. electric vehicle
mailing list.  reprinted with permission.

-----------------------------------------


     Battery technology was the subject of Saturday's meeting of the EVAOSC.  A
representative from Trojan batteries was the speaker.  They are the major
player in the golf-cart battery business (they have 60% of the EV business
right now).  The speaker was a *BIG* proponant of lead acid batteries for
several reasons, the primary one being cost, but also the level of recycling
--MORE--(31%)

(apparently last year 98% of all lead acid batteries that had reached the end
of thier life-cycle were recycled).

     He came up with some formula that "showed" that lead-acid batteries were 
the way to go with electric automobiles.  I believe that the formula was 
something like: 

(Energy Density)*(Energy "availability")*(# of cycles)
------------------------------------------------------  == Value Index
                      Cost  

Using this formula he "showed" that lead-acid batteries were the best 
alternatives for the short and mid range.

     Then we had an interesting discussion about how environmentally friendly
the materials are.  Lead is no angel, but of the heavy metals it is one of the
safest.  Cadmium (the "Cad" in Nicads) is pretty nasty stuff, and in
zinc-bromine batteries the bromine is very toxic (the battery also has many 
potential failure points because it requires a fair amount of plumbing).  Of the  
other major technologies, sodium-sulphur has to be kept at about 300-400 degrees  
Fahrenheit (which could be really nasty in an accident).  The others are 
--MORE--(64%)

probably no worse than lead-acid, but they have their own problems.  Zinc-air 
(probably Zinc-nitrogen?) and nickel-iron are both currently very costly and 
have no recycling network.  (Both of these *COULD* change.)

     I'm curious what the net thinks about these various technologies and how 
they view the future.  If you've heard of a battery type that I haven't 
mentioned here, I'd like to hear about it.  One thing that I should mention is 
that most people I've talked to think that the long term solution for EV power 
will be some sort of fuel cell.  At that point you are basically using hydrogen  
as a storage medium.  (Anybody know about the current state of fuel cell 
technology small enough for EV applications?)

-- Chris Yoder                  Internet --- Chris@HMCVAX.Claremont.Edu
     VMS Systems Manager
     Harvey Mudd College        Bitnet ----- Chris@HMCVAX.Bitnet


-- 
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Tyler Holcomb   *   "Remember, one treats others with courtesy and repsect *
tylerh@juliet   *   not because they are gentlemen or gentlewomen, but     *
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End of article 48 (of 72)--what next? [npq] 58
