Concordes (was Deka vs. Absolyte Batteries) [RE-wrenches]

Tue Feb 11 10:58:14 PST 2003

We've been very happy with the 100's of Concorde's we've got out there. We
used them almost exclusively since 1998 for all small to nearly large
applications but only time will tell. The only big 2 volt batteries we've
used have been flooded lead acid and even some old Edison cells (ni-cads).

The Concordes have proven to be trouble free.  Unlike our flooded battery
installations we where we been called (at home) by a panicked customer with
a dead system at 7:30 am Sunday.  "My systems dead, it's been acting funny
all week, what do I do?".  I ask them  "have you been maintaining your
batteries?" and they usually admit it's been a year or so since they have. 
These are customers who appeared to be excited about being hands on and
promised me when we were designing the system that they would maintain their
batteries.  Ah, but how soon they all forget that promise. 

The next few years will be interesting about the long term success of the
Concordes.  We've found them to have incredible low self discharge, be very
charge efficient and quite robust.  The factory amp-hour rating is probably
a little on the generous side but I think everyone's is.

Warning to all of those who don't install battery based systems: Long
battery story follows.

I recently found 2 of the big 12v/255 ah batteries at less the 1 volt each. 
An inverter had failed locking its cooling fans on.  No other charging
source for the batteries and they were left like that for months before I
was called.  I brought them back to my shop and carefully took them through
some cycles.  At first, just a few amps would immediately take them past 15
volts and they started gassing a little bit.  I put one of them on test a
system in my shop with about 8 amps of PV and Solar Boost 50 and TM2020.  It
was a sunny day and the SB50 immediately took the voltage past 15 and
dropped into float.  The battery stayed at float with just over an amp. 
Over the next few hours I watched and to my surprise the SB50 kept cranking
the amps up to keep the battery at float.  Maybe a .1 v every 5 minutes. 
Sun appeared to be constant so what was happening was as each mAh went into
the battery it was coming back to life.  Periodically I would disconnect the
PV then reconnect it.  As expected SB50 would go into bulk hitting the
battery with all the 8 amps and the would shoot up to over 15 so the SB50
went into float again.  

After nearly a day it couldn't keep the battery at float with 8 amps.  Then
I hooked the battery up to a 30 amp/3 stage charger and saw that it took all
30 amps to get the battery to bulk.  Took the battery through a few deep
discharge and charge cycles and then did a capacity test using an inverter,
incandescent lights and a TM2020.  At a ~C/20 discharge rate I was getting
about 175 ah hours out of the battery cutting the test off at 11.0 volts.  I
think most manufacturers rate the capacity at a cut off of 10.5 volts (1.75
vpc).  Remember I found it at less than 1 volt.  The other battery responded
the same way.  These batteries had been in grid back up application in float
mode and had probably seen less than 20 50% DOD cycles in the 3 years they
had been installed.  In my shop I did use the 4 amp 12 volt VDC Electronics
battery desulphator on them.  If I had of been thinking I would have not
used the desulphator on one and could have done the AH test to see if it
actually does anything.

The above results might no have anything to do with them being Concordes.  I
also took 4 practically new Trojan T105's through the same procedure
recently.  They had been left on a RV and had been drawn down to less than 1
volt each and left like that for months.  They were less than a year old and
probably had less the 5 cycles.  They've come back to life just fine and
their AH capacity appears to be just over 160 amp hours @ C/20.

Travis Creswell
Ozark Energy Services

----------
>From: Bill Roush <solarguide at everestkc.net>
>To: RE-wrenches at topica.com
>Subject: RE: Deka vs. Absolyte Batteries [RE-wrenches]
>Date: Tue, Feb 11, 2003, 10:12 AM
>

>Never a known problem with a Concorde. I once set some in the
>unconditioned warehouse for a year (I was going to 'top them off
>periodically', of course), and after the year had passed they still
>showed 12.5+ volts or so, memory a little foggy hear on the exact
>number.  They are only pricy if you don't count the vent caps,
>equalizations, testing, acid caution, shipping concerns, total lack of
>customer maintenance, and tons of aggravation caused by flooded
>batteries.  I won't sell flooded batteries because I don't want
>customers coming back unhappy.
>
>Best,
>Bill Roush
>
>
>

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