[RE-wrenches] Surrette Battery Question

Sun Aug 3 18:46:10 PDT 2008

Hi bob,

Wow now thats unusual!

So have you figured out a better charger or are using a IBE or similar?

jay
On Aug 3, 2008, at 6:02 PM, robert ellison wrote:

> The 80 volt battery banks are not on inverters, sorry I didn't  
> mention that.
> They are 2 - 20 cell packs in series for 80 volts total.
> These power a Zamboni. I didn't know what one of those was either  
> when they called me to work on the batteries 10 or so years ago.
> These are the machines that groom the ice on skating rinks, in most  
> cases you can't use an engine inside a building anymore, so they  
> are going electric.
> I did put out some feelers a few years ago about building a 3 stage  
> charger to charge them. Many are still using the transformer based,  
> taper type charger we got away from years ago.
>
> It's another cool toy I get to play with.
>
> Later,
> Bob
>
> On Sat, Aug 2, 2008 at 12:31 PM, jay peltz <jay at asis.com> wrote:
> HI Bob,
>
> What are you using 80v battery banks for or which inverters anyway?
>
> Would be great for larger systems.
>
> thanks,
> jay
> peltz power
>
>
> On Aug 1, 2008, at 10:18 PM, robert ellison wrote:
>
>> When i went to an SEI class at the Trojan factory one of the  
>> points mentioned was that the best way to get the lowest cost per  
>> watt from the battery bank
>> (T-105's were at the time the lowest) was to cycle them to 80%  
>> discharge then fill them all the way up. Not feasible in an off  
>> grid system at all.
>> We get more years life by just taking off the top 20 - 25% and  
>> returning it daily.
>>
>> My battery distributor says that an industrial deep cycle battery  
>> needs to be cycled occasionaly to prevent them developing a  
>> "memory" so to speak.
>> I recommend to my customers that they occasionally let them run  
>> down to 50 -60% DOD and fill them back up with an EQ charge to  
>> stir up the electrolyte so you can get an accurate reading with a  
>> hydrometer.
>> Stratification will throw off the gravity readings unless they get  
>> stirred up occasionally.
>> I have pulled apart batteries that did not get an EQ and found the  
>> bottom of the plates wore out and the top still looking reasonably  
>> good. That is from the acid being a lot stronger at the bottom  
>> than the top and just working on the bottom of the plates in the  
>> battery. This is not a "fun" project and usually results in some  
>> trashed clothes, rubber suit or not.
>>
>> I have 80 volt battery packs that get cycled to 70-80% DOD daily  
>> for 5 months a year then sit for 7 months with just a couple  
>> freshening charges and last 6 - 7 years till wore out, some of  
>> these are hi acid batteries that are in the specific gravity range  
>> or 1.325 or more when fully charged instead of the usual 1.265  
>> -1.270 that we are used to seeing.
>>
>> I am not a battery "expert" I just have several big banks that I  
>> maintain and have formed some opinions over the last 15 or so years.
>> I have also experienced wearing out a set of L-16's by hitting the  
>> end of their cycle life in just over a year. It was way too small  
>> a battery bank and got cycled fully almost daily hitting it's  
>> cycle life limit far sooner than a larger bank would have if  
>> treated well.
>>
>> Good night,
>> Bob
>>
>>
>>
>>
>>
>> On Sat, Aug 2, 2008 at 12:01 AM, jay peltz <jay at asis.com> wrote:
>> 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.
>>>
>>>
>>>
>>
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