We are only on your back until you to do the advisable thing: Sell them a battery capacity monitor. It is a hard fact that NO off grid, battery based power system should be without a battery capacity monitor. They are cheap (only $150!) and not an option. Apparently, it is also hard learned fact. ;-)
Larry Crutcher Starlight Solar Power Systems On Nov 16, 2011, at 12:20 AM, Ron Young wrote: > 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, <[email protected]> > <[email protected]> wrote: > >> Ron, >> I stick by my evaluation as seen here: >> http://www.mail-archive.com/[email protected]/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 <[email protected]> >> Date: Sat, November 12, 2011 9:57 pm >> To: RE-wrenches <[email protected]> >> >> 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: [email protected] >>> >>> 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: [email protected] >> >> 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: [email protected] >> >> 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: [email protected] > > 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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