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 > >
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