Jay has a real strong point. If you are near low voltage low state of charge. Two or 4 hrs from a 4kw array is only 8 to 16 kwh nowhere near 46 kwh. Given the recomended max charge rate is C/5 you would have to be charging for days
On Fri, Apr 19, 2019, 10:20 PM John Blittersdorf < [email protected]> wrote: > Mac, > If there is a TriMetric or charge controllers, you can get min/max > voltages each day or since last reset. I have found that is very useful > info when large, short duration loads hit. ie well pump. I would find on > one of my 24 v systems that an 18 or 19 v min would indicate that the well > pump went on when the batteries were quite low and pulled the voltage down > to low battery cutoff. If the system does not shut down, you might see a > voltage lower than the 2 minute setpoint. I think the FlexNet DC also > records minimum voltage. And be sure that the gen start trigger is not the > flexnet as that is big trouble. > > John Blittersdorf. > > On Fri, Apr 19, 2019 at 8:06 PM Glenn Burt <[email protected]> wrote: > >> Hi Larry, >> >> >> >> I am curious why you would use the 100Hr rate for this approximation and >> not the 20 or 24Hr one, since that is the period in which Mac is reporting >> the anomaly. Happy to learn the details! >> >> >> >> Thanks, >> >> Glenn >> >> >> >> *From:* RE-wrenches <[email protected]> *On >> Behalf Of *Starlight Solar Power Systems >> *Sent:* Friday, April 19, 2019 3:10 PM >> *To:* RE-wrenches <[email protected]> >> *Subject:* Re: [RE-wrenches] Operating Voltages Outback RE High Capacity >> Battery >> >> >> >> Mac, >> >> >> >> Only removing 6kWh from 46kWh of storage should not be able to produce >> the voltage sag to trigger AGS. That’s only about 13% at a 100Hr rate. >> Voltage should be no where near that point. Have you verified actual >> voltage when the AGS is triggered? Loose wiring or terminal corrosion can >> cause voltage drop but I would think that an easy find/repair you would >> have checked. >> >> >> >> Saying the battery easily charges to 100% worries me as sulfated >> batteries do that. Healthy LA batteries take many hours to reach full >> saturation. Has cell voltage been compared for non-uniformity? Has the >> equalization charge been performed? >> >> >> >> I am not a fan of the unusual low voltages that Outback prescribes for >> EnergyCells and seriously wonder how these voltages can properly maintain >> these cells. CV is below the point where balanced O2 and H2 evolution takes >> place. But, thats off point. >> >> >> >> >> Larry Crutcher >> Starlight Solar Power Systems >> >> >> >> >> >> >> >> On Apr 19, 2019, at 10:27 AM, Mac Lewis <[email protected]> wrote: >> >> >> >> Hello Wrenches, >> >> >> >> We recently inherited an Outback system that I've been keeping an eye on >> via Optics. Its a dual stack 3648 VFXR, with about 4kW of PV with a single >> string of EnergyCell 1100RE battery bank (reported to be ~6 months old) >> ~.46 kWh at C20. >> >> >> >> I have been observing how the system functions and how the voltage >> behaves. We keep getting 2 minute voltage starts on the generator in the >> middle of the night that don't seem necessary judging from how much energy >> has been used from the battery bank. I am hesitant to tweak anything >> because these battery set-points are a bit different than I'm used to. >> >> >> >> As per Outback: >> >> Absorb Voltage is 55.6V for 2 hours >> >> Float Voltage is 54.0V >> >> >> >> I've slowly been dropping the 2 minute start voltage to see if there is a >> bottom, but I'm hesitant to take it much lower (maybe I should). >> >> 2 minute start voltage: 44.8 V. >> >> >> >> >> >> The system easily charges the battery bank to 100% (and easily reached >> the 2 hr absorb time) every day. The flexnet DC is correctly set up and >> calibrated. >> >> >> >> The load on the system is pretty consistent. They use between 400 and >> 600W throughout the night. >> >> >> >> An average night, they may use about 6 kWh before the voltage sags below >> the 2 minute start voltage and it starts the generator. >> >> >> >> Just curious if our 2 minute voltage needs to be dropped or if these >> batteries are degraded. What corrective changes can I make to get better >> performance? >> >> >> >> I have and will call Outback about this, but I'd like other perspectives >> as well. >> >> >> >> Thanks as always for your expertise >> >> >> >> -- >> >> >> >> >> >> >> >> Mac Lewis >> >> >> "Yo solo sé que no sé nada." *-Sócrates* >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: [email protected] >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/[email protected]/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> _______________________________________________ > List sponsored by Redwood Alliance > > List Address: [email protected] > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/[email protected]/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
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