Good question. Voltage slowly drops in a fairly linear fashion through out the night. If it is a sudden short duration load, it is short enough that Optics can't pick it up, or it get's averaged out. When I've been on site, I didn't observe any loads that caused concern.
On Fri, Apr 19, 2019 at 11:45 AM Roy Rakobitsch <winds...@gmail.com> wrote: > Using Optics, can you equate the voltage sag/ gen start command with a > particular load? Or is the voltage dropping quite evenly over the course > of the night? They could actually be degraded if there is no indication of > a sudden load/ voltage drop. A simple load test when on site can also help > you replicate and/or get a better picture of whats going on. > > > Roy Rakobitsch > NABCEP Certified Small Wind Installer® > Certified Advanced Tower Climbing, Safety & Rescue > Wind/PV Design Engineer > Windsine LLC > 631-514-4166 > www.windsine.org > > > > > > On Fri, Apr 19, 2019 at 12:27 PM Mac Lewis <maclew...@gmail.com> 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: RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/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: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > -- Mac Lewis *"Yo solo sé que no sé nada." -Sócrates*
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