[RE-wrenches] intermittent battery problem; ...Battery Sulfation

[Jeff Yago]

Ron,

 

This reply a little late since I have been off line a few days.  I mentioned
in a similar thread last year that I had an off grid home client I designed
and installed in Idaho back in 1998 that had a Kohler 8.5 kw generator, a
Trace 4024 inverter, two separate solar arrays and Outback charge
controllers, and 16 Trojan "L-16" batteries.  This system worked flawlessly
for 7 years and only required the generator a few hours per month, then it
was time to change the batteries.  I replaced the Trojans with the same size
battery made by Surrette and everything went to crap.  They had to run the
generator hours and hours to get them past an 80% charge and we had lots of
problems with overloading the generator even though we did not make any
program changes and used the same generator.  The generator was replaced 2
years later but this system  never worked like it did before the battery
replacement.

 

When researching all this at that time I had talked with Surrette, Trojan,
and anyone else that might help and this is what I found out.  Of course
there are just my opinions based on these conversations, but it is my
understanding that Surrette is a much longer life battery with much less
water loss when comparing apples and apples, and I was told this was due to
a different lead composition that Surrette uses than any other battery
manufacturer.  However, this difference requires a much longer
absorption/taper off charge process or you will never get it past 80%
charged.  This of course is almost impossible to achieve with a generator or
undersized solar array, and you really need a grid connection to fully
charge these things.  No doubt these would be great in some standby grid
connected system but I no longer use them in off grid.  This was also at a
time when battery manufacturers were just discovering solar so maybe battery
designs have changed.  Again, I think Surrette is a good company and makes a
great battery, but just not sure you can fully recharge them with a
mid-sized generator.

 

I also do not like using parallel battery layouts as its hard to keep one
string from pulling down the other strings when there is a low performance
cell so you might do a cell by cell check.

 

Good Luck,

 

Jeff Yago

DTI Solar Inc.

 

----------------------------------------------------------------------------
----------------------------------------------------------------------------
----------------------------------------------------------------------------
-----------

This is not what I expected after a lengthy EQ. I'm getting them to do
another one tomorrow after a discharge cycle and charge but I'm really
beginning to think we have something else going on here, something
electrical, not chemical. The rapid voltage drop is puzzling. 

 

To review, it's an Outback 3524 on an Epanel, Whisper 100 & controller, 6
4KS 25 Surrette batteries in 24v configuration - 4.5 years old, .7kw solar.
I know the charging end is undersized but they have been compensating with
the generator and they get lots of wind in the fall, winter, spring.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20111116/3b7715b8/attachment-0003.html>