Larry, the customer has been fully charging and equalizing every week to two weeks for several years. They also are diligent about checking the batteries with a hydrometer. It turns out then that I, and the customer, have put too much faith in hydrometer readings to give an accurate picture of battery health? Yes I agree (long time ago) the battery monitor would have been helpful in catching the problem - if this is the problem. A couple of other posters have suggested another possibility: a fractured bus bar inside the battery or a dead cell. Both of these suggestions came from people who experienced almost identical problems that were extremely difficult to detect. I have recovered several sets of sulphated batteries, Surrettes, Trojans, Yuasa, so I know what they are like and what they smell like when subjected to a high amp charge.
I have several sets of these KS25's & 21's in the field and for the most part they have worked very well but I've seen customers sulphate L-16's in a few weeks of deficit charging, it just takes longer with a big battery especially when they aren't really being abused. I'm sure hoping the horse hasn't left the barn on this one. Ron Young On 2011-11-17, at 12:32 PM, Larry Crutcher, Starlight Solar Power Systems wrote: > Ron, > > From what Daryl said below and the fact that your customer has about 15 amps > of PV charge, you should deduct that the batteries have MOSTLY been deficit > charged their entire life. Here's what I told you on Oct 22 in my lengthy > explanation about what the problem is and why it happened: "Undersized RE > charging systems, or perhaps oversized batteries, is the culprit that > contributes to this all too frequent phenomenon of chronic undercharging." > > You said that the customer has been compensating for an undersized system by > running a generator. They can not know this because there is no monitor. The > batteries now have a sulfation problem, perhaps unrecoverable, that could > have been prevented if the owner had a battery capacity monitor. This is not > pleasant news, I know. I have to explain this bad news to people MANY times > each week. This is a huge issue globally. And such waste of money, time and > resources just bugs me! > > Larry Crutcher > Barer of Bad News > Starlight Solar Power Systems > > On Nov 17, 2011, at 5:17 AM, penobscotso...@midmaine.com wrote: > >> Ron, >> I'm going to reiterate what Jeff says here. It is similar to what I had >> said in my email. The charge rate must REGULARLY be C10 on the KS >> (5000 series) batteries. This means, on KS 25's, a routine bulk >> charging rate of 135 amps. I find that on these types of hybrid >> systems, while the batteries might occasionally (sunny day, generator >> running, etc.) that kind of charging, they do not regularly see C10. I >> think if you gave Jamie Surrette a call he would give you the same >> possible assessment. >> I do think the problem is oversulfation, but none of this solves your >> problem, I know. We have been installing KS series batteries since they >> came out and this necessity of regular C10 charging has been an >> integral part of design for me for many years. >> >> Best, >> Daryl >> >> >> >> >>> 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. > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
