Hi Larry, no amp hour meter installed yet as the customer is penny pinching. We're trying to solve the problem first and I've been out there twice, once to do general diagnostics and check all connections, try to load test the batteries, and so on; the second time I 'dropped in' to try a different load test on the batteries to see if I could replicate the problem and to resolve some other problems with a Whisper controller that had given up the ghost when disconnected & re-connected to the batteries (all precautions taken). It's a seven hour round trip and with time spent on the job makes for an expensive service call. I only charged for one call and I have to go back at least once more. So customer wanted to save some money on the installation of the TriMetric until the spring... sorry for the long winded reply. I know, it's false economy. So I'm thinking I'll just put the meter in and tell them to pay me when they feel like it. It'll help solve the problem and get some of the Wrenches off my back ... ;-)
Ron Young On 2011-11-13, at 8:26 AM, <la...@starlightsolar.com> <la...@starlightsolar.com> wrote: > Ron, > I stick by my evaluation as seen here: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/msg10694.html > > The #1 reason for my opinion is that you can NOT drive up voltage on a > healthy bank that size in just 5 minutes. It is impossible with a 2500 watt > generator. > > Here is the pertinent part from my post: > You mentioned that the the battery drops to 24.5 in the early AM without any > heavy loads on. For the 4KS25 battery this equates to about 800AH at the 72 > hour rate. Then you said that the customer ran a 2500 watt generator for 5 > minutes and drove the voltage up to 29 volts. Here's the Ah-Ha moment: That > is EXACTLY the behavior of a heavily sulfated battery bank. A fast rise in > voltage indicates sulfation. It is impossible for that tiny generator, or any > charge source they own for that matter, to replace the hundreds of AH it > would take to drive a healthy battery up to the absorb voltage of 29 volts. > The bank is about 45,000 watt hours (72h rate). There would have to be over > 20,000 Wh removed to be at that voltage. How many Wh's are replaced in 5 > minutes by a 2500 watt genny? I'm sure you are getting the picture. > > Also, why have you not installed a battery monitor yet? It will give you > "eyes" into the battery and spare countless hours of time diagnosing the > problem. > > Larry > > -------- Original Message -------- > Subject: Re: [RE-wrenches] intermittent battery problem; ...Battery > Sulfation > From: Ron Young <solarea...@solareagle.com> > Date: Sat, November 12, 2011 9:57 pm > To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > > 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 >
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