[RE-wrenches] Surrette Battery Question

[jay peltz]

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 Any of these thoughts are superseded by  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  
> <allan at positiveenergysolar.com> 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.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20080801/c65cb240/attachment-0003.html>