Hi Daryl. I've got other KS25's in hybrid systems (wind gen & solar) that seem to do fine over the last several years. The Ouback 3524 has an 85 amp charger. There was no problem getting to 32 v and holding it for eight hours. This has been done twice now. Larry and others attribute the ability to get to 32v to a sulphated battery condition and I'm thinking that a healthy battery could get to 32v as well, especially one that's been regularly EQ'd... am I wrong?
I'm listening to every opinion here and trying to sort it out but I think John may be on the right track with an intermittent failure of one cell. I just can't seem to find it. Ron Young On 2011-11-13, at 3:51 AM, penobscotso...@midmaine.com wrote: > Ron, > What comes to mind for me is that Surrette 5000 series batteries like > to have a regular charge of C10. KS25 cells are rated for 1350 ah, > creating a need for a somewhat regularly occurring charge of 135 amps. > I do believe the batteries are not ever getting that, except for very > rare occasions. We have seen this before in undersized systems. > Is the bulk charge set to 29.6? I would try a couple more eq's over the > next month to loosen likely sulfation. Get it up to as close to 32 > volts as possible and taper the charge down, then eq at that voltage > for four or five hours, even more if the client will do it. > That would be how we would deal with this. It does seem ultimately to > be sulfation that is the problem. > > Daryl DeJoy > NABCEP Certified PV installer > Penobscot Solar Design > > > > >> Folks, this one really has me puzzled. The client has done regular two >> hour EQ's, at least once a month. When did a site visit and I topped up >> the electrolyte (they'd been starving the batteries for water but always >> just above the plates) the problem seemed to go away. They were satisfied >> that the problem was solved but I wasn't and I told them what I had been >> hearing from this group - essentially that the batteries needed a deep EQ, >> discharge, recharge and EQ again two or three times to scrub the >> sulphates. They declined until just a few days ago when they said the >> rapid voltage drop was back. Here's a quote: >> >> We had another rapid voltage loss this morning ---it was 25.2 when we got >> up and it dropped rapidly to 22.8. We turned on the generator and charged >> the batteries until our display showed 30.2 for awhile with the generator >> running. We turned off the generator and the voltage settled at about >> 26.4. We turned off all loads and wind and solar. >> >> At 9.15 our batteries were at 26.4 >> At 9:16 we turned on an 8W light bulb, a1600W hair dryer, and a 1.5HP >> (120V 5.75A) shop vac >> The display showed a load of 1.9kw >> At 9:40 the inverter shut down---display showed batteries at 18.4 >> By 9.47 the display showed the batteries at 25.2----the solar and wind >> were still shut down. >> We turned everything back on (a light, Sunfrost RF16, phone) and all >> seems to be normal. >> >> They agreed to do the EQ process but only have a 3kw generator so we >> started with 8 hours with the EQ voltage set for 32v (24v system). They >> completed that yesterday and here's what resulted: >> >> Before starting EQ the batteries were at 25.8, hydrometer reading 1283 >> with temp. correction >> Began EQ 32.6 v >> Buying >> 1.5 kw >> Hour 1 32.4 v >> 1283 with temp. correction Buying 1.4 >> Hour 2 32.4 v >> 1285 with temp. correction Buying 1.5 >> Hour 3 32.2 v >> >> Buying 1.7 >> Hour 4 32.2 v >> 1290 with temp correction Buying 1.8 >> HOur 5 32.0 v >> 1290 with temp correction Buying 1.8 >> Hour 6 32.0 v >> Buying >> 1.9 >> Hour 7 31.8 v >> 1292 with temp correcton Buying 1.9 >> Hour 8 complete---turned off Gen and turned on loads ---Batteries dropped >> to 25.4 within 30 minutes and stayed there until this morning---fridge was >> running, telephone, internet, wool carding machine, lights. This morning >> hydrometer reading was at 1290. >>> >> >> >> Then today I just got this email: >> >> Just experienced another rapid voltage drop. As soon as the voltage hits >> 24.8 the voltage drops like a rock if we don't have any input (no solar or >> wind). >> >> 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. >> >> Any more thoughts on this anyone? >> >> Best Regards, >> Ron Young >> earthRight Products - Solareagle.com >> Alternative Energy Solutions ~ Renewable Energy Products >> >> >> On 2011-10-24, at 6:50 AM, Larry Crutcher, Starlight Solar Power Systems >> wrote: >> >>> Hi Ron, >>> Accurate SG readings are not simple. Was temperature compensation >>> properly employed? Have they been keeping a log book to identify >>> changes? How accurate is the hydrometer? How skilled is the person >>> taking the reading? >>> >>> Most of the Battery Wrench responses suggest equalization but I don't >>> see from any of your posts that this has been done yet. I suggest this >>> to be the next step and I recommend that you carefully watch voltage and >>> current. This will tell you a lot. I use a Fluke ScopeMeter in the >>> TrendPlot mode and track voltage and current over time. It provides a >>> good visual understanding. >>> >>> In case others are using this forum to glean information, attached is a >>> chart for illustration of the charge cycle. You should see a constant, >>> somewhat linear rise in voltage until the constant voltage setting is >>> reached. If you see a sudden rise: suspect sulfation. If you see a quick >>> reduction in current: suspect sulfation. The current should drop to >>> about 8-10 amps at the constant voltage towards the end of charge cycle. >>> The health and DoD will determine the time this takes, expect many >>> hours. Begin equalization. >>> >>> <3s-chart.gif> >>> >>> A couple other points: Is the MX absorb voltage at 29.6V? Did you >>> program the MX controller for an extended absorb time (advanced menu, >>> absorb time limits)? The default setting is poor for large batteries. I >>> use 90 minutes minimum and 4 hours max. This can greatly reduce the >>> possibility of undercharging the battery but it may use more water. The >>> timer (ChgT) will determine how long it stays in absorb each day. >>> >>> Larry Crutcher >>> Starlight Solar Power Systems >>> >>> On Oct 24, 2011, at 12:49 AM, Ron Young wrote: >>> >>>> Hi Larry, >>>> >>>> I immediately assumed sulphated battery when I heard the customers >>>> description a couple of weeks ago but the hydrometer readings didn't >>>> jive. Any sulphated battery I've encountered, and I defer to your >>>> greater experience, has always revealed itself with a simple S.G. test >>>> and these batteries were reading above 1.265. I then thought the >>>> possibility of a defective hydrometer and had them test with another >>>> but we just got confirmation of the same thing. >>>> >>>> The weird drop in voltage also isn't explained by your description. Why >>>> would this just happen without loads or charging present (except maybe >>>> the DC Sunfrost load) at the same predictable time at 4 a.m. The fact >>>> that when the generator was turned on and sent a surge of current into >>>> the system and the problem went away made the detective in me think >>>> there had to be another explanation. The bank was at rest for several >>>> hours through the night and the voltage dropout was cured by a brief >>>> application of charge current. >>>> >>>> When I arrived on site my discovery that the client was under watering >>>> the batteries and this chronic condition resulted in a very rich >>>> electrolyte, reading well above 1.265 - into the 1.280 range made me >>>> think that was the problem and it seems to have gone away now that the >>>> electrolyte level was raised and the batteries given a good charge. But >>>> it still nags at me that something else is lurking in the shadows. Your >>>> description of the sulphate converting to a crystalline form has me >>>> worried because if this is the case this expensive battery bank is in >>>> danger. I would have to camp out at the site and monitor the charging >>>> over a day or so. I'm going to forward some of your comments and those >>>> of others that have generously offered suggestions and we'll see if I >>>> can convince the client who now believes everything is A-Ok. >>>> >>>> Best Regards, >>>> Ron Young >>>> earthRight Products - Solareagle.com >>>> Alternative Energy Solutions ~ Renewable Energy Products >>>> >>> >>> _______________________________________________ >>> 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 >> >> > > > _______________________________________________ > 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
