Hi Robert,
When you mention cycling batteries, are you saying that batteries in
a offgrid system that are being cycled 15-25% a day should be cycled
even deeper than that?
Thanks,
jay
peltz power
On Aug 1, 2008, at 8:36 PM, robert ellison wrote:
A couple things that I haver noticed in the past, sometimes
batteries like to be cycled, shut off the controllers and run them
down, then charge them up fully and then give them an eq charge
till it comes up the peak voltage and hold it there as it
(sometimes) slowly rises. Any of these thoughts are superseded by
Jamie if he has any thoughts.
Also, if you have not given them an eq in a while it might take
longer than the available solar time has to get them to the top and
hold them there..
Have the controllers settings changed?
Bob
On Fri, Aug 1, 2008 at 10:18 PM, Allan Sindelar
<[EMAIL PROTECTED]> wrote:
Wrenches,
In late 2003 we installed a 24V set of Rolls-Surrette 4-KS-21PS 6V
1104 A/hr batteries in the off-grid system of a long-time client.
The client's system had a democracy array of around 800 watts of
tracked PV. In early 2005 we added 1,280 watts of additional PV,
and the client hasn't run the generator since; the system rarely
drops below 80% and fills to 100% most days in sunny New Mexico.
Batteries are located in a basement, so temperatures stay
relatively constant, although it will vary slightly seasonally.
MX60 controller is temperature compensated, with 29.6 VDC bulk and
31.4 VDC EQ set points.
The problem is that the client reports being unable to achieve
previous EQ voltages, and this inability appears to be a new
development. The system is otherwise performing well. As the client
is sharp and pays close attention to the system's operation, I'm
not ready to blame user ignorance (with one possible exception;
read on). This may be an issue of seasonally warm temperatures, but
I'm not sure this would explain the full 0.4 VDC reduction in
voltage. I told him that I would post his problem to this list, and
also request advice from Surrette Battery.
Here is the client's description of the symptoms:
I'm concerned that I am unable to equalize batteries at this time. Up
until June of this year the Tri-Metric readings during equalizing
indicated
holding voltage at 31.1, with maximum amps gain of around 52.
Three weeks
ago, when set on equalize, the maximum voltage reading was 30.7, with
maximum amps of 46; this was reached around noon, and by around
1:30 pm
voltage/amps began its typical afternoon drop-off. I attempted
equalizing
on two other occasions since then--the last time this past
Saturday, with
clear skies up until mid-afternoon--but having the same results.
So, the
question is: are my batteries beginning their decline? We've had
this set
for 4 1/2 years, so it would seem a bit too early for this, given
that these
batteries are expected to last 7-10 years.
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