Day Brown wrote in a message to Roy J. Tellason:
 RJ> I know that electric cars would need more speed capability,  
 RJ>  and that range seems to be most often the quoted "problem"  
 RJ> with them.  Anybody else care to comment on this stuff? 
 DB> I usta have TELCO 2 volt cells that were 35 years old, and 
 DB> still in excellent condition.
I remember seeing some cells that I think came out of a railroad equipment of 
some sort,  these things were *big*,  and glass,  and also 2 volts.
 DB> The durability of lead cells is related to the density of the 
 DB> sulfuric acid (these being 50% of vehicle types) which affects 
 DB> the power density... duh! 
I wish I could get a better understanding of how that worked.  When I had 
that battery store you could put pretty much the same electrolyte in most of 
what was in there,  one exception being the so-called "maintenance free" 
types made for some ATVs,  which came with their own acid pack and a sealing 
strip.  You'd fill it,  which would activate it,  and then pop the sealing 
strip into place,  and that was it for the life of the battery.  They had a 
heck of a long life,  saw some come in that were ten years old,  and could be 
flipped over with no spill hazard.  They were also not vented the usual way,  
either.
 DB> And, the depth of discharge affects the rate of sulfation, from 
 DB> zero for a battery that stays 90% charged, to 100% for a cell 
 DB> in complete discharge. 
Actually,  sulfation is dependent on how long a discharged battery stays that 
way,  rather than only how deep the discharge is.  Overall lifetime of a 
battery will be affected by depth of discharge,  too.  I remember seeing 
something in the training materials that I read that compared the lifetime of 
a set of golf cart batteries that were charged back up after nine holes vs. 
another set that were not charged until after 18 holes.  The difference in 
life expectancy was considerable.
 DB> Like you say Roy, there aint no free lunch.  
Yep.
email: roy.j.tellason%tanstaaf@frackit.com 
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