Re: Dynasty Group 31 AGM (was Battery Cycle Life/Cost)

[Mike Chancey <evtinker@evalbum.com>]

Hi folks,

Last night I emailed Dynasty and asked their opinion and recommendation on 
what battery would be suitable for my Civic, and what kind of cycle life I 
could expect.  This was the nice response I got from Tom Ruhlmann, 
Technical Services Manager.


>Mike,
>
>I would suggest the DCS-100 also.  The loads are not a problem.  It has 
>high density plates and high compression element and as a result delivers 
>superior cycle life.  Send your fax number and I will send a data sheet 
>and cycle life curve.


The cycle life curve and data sheet arrived shortly after I passed my fax 
number along.  The data sheet is identical to the one on the web at:

http://www.dynastybattery.com/cd_dyn/products/batteries/dcs/dcs100l.htm

The cycle life data looks great, almost too good.  Translated it looks like 
this:

% Discharge: Number of Cycles
90%:~360 cycles
80%:~450 cycles
70%:~600 cycles
60%:~800 cycles
50%:~1200 cycles
40%:~1800 cycles
30%:~3000 cycles
20%:~4000 cycles
10%:~4200 cycles

The table also notes "Application and Typical Failure Modes":
for discharges of less than 20% "Float/overcharge Failure"
for discharges of 18-38% "Transition"
for discharges greater than 38% "Cycling Failures"

I am not really sure what they mean by "transition".

So, what do folks think?  It kind of looks like, at least in theory, these 
batteries would last more than 3000 cycles in my usage, or about  4 
years.  That would work out to about 34,000 miles on a battery pack, which 
sounds too good to be believable.  Is it?

Thanks,

Mike Chancey,
'88 Civic EV
Kansas City, Missouri
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