[ausev] Open Garage this Sat... 9am - 1pm

[Brian Lasseter]

On Thu, Aug 13, 2009 at 11:08 AM, Marc Kohler<mkohler at austin.rr.com> wrote:
> Brian, what batteries are you going to replace them with?  Same ones or
> something different?

Sorry for my late reply... I was busy replacing my batteries.  I was
back on the road as of Monday driving to work with a new sat of the
exact same batteries.  18x  US8VGC batteries.   I look forward to the
day when I can take my car to Jiffy Lube to water my batteries, or to
the local Interstate dealer to replace my batteries.   :-)

I also replaced my small 12VDC 10Ah battery on Tues, as whenever I
turned my steering wheel to one side or the other (causing a high
current draw from the power steering pump) the voltage would sag far
enough to cause the Zilla motor controller to cut out.  Once I removed
the old 12VDC battery, it read 7 volts on my voltmeter.  (And that was
minutes after removing it from my DC/DC converter that was
continuously trying to charge it.)


> How many cycles are on them?

I got exactly 346 cycles on my last set of batteries.


> What is the average depth of discharge?

I would say I took the batteries down to 40% of charge left on average
(60% DOD).  But I went down to only 10% left probably once a month
(90% DOD)


> Perhaps you could discharge one at 25A and compare it to published data to
> see where it falls on the graph.

Hmm... yeah... It was all I could manage time wise just to get the
batteries replaced in 3 weekends.  However the batteries were still
getting my about 70% of their original energy rating at the time I
retired them.  The problem was that charging them was difficult due to
the extreme heating, and inefficiency of charging.   Had I used some
sort of active cooling mechanisms on the batteries, they might have
lasted another 2-3 months.  But the energy used in cooling the
batteries, and the fact that the batteries were taking twice as much
energy to charge as per normal was eating into my efficiency.



-- 
TTFN,
Brian "Lasso" Lasseter

"No Sane man will dance."   -Cicero (106-43 B.C.)