The LG RESU series will trip it's breaker at around 10% Soc. It will require a human unless the LVD on the inverter is set higher than the battery. Yes Sir it is our responsibility to educate our users or have plane tickets (:
Will be installing the Discover battery soon into Xanbus. Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail offgridso...@sti.net text 209 813 0060 > Hi Drake, > > I agree. Li-ion batteries, like lead batteries, should always have a human > overseer. This is a difficult reality to convey in our set-it-forget it, > automated world. > > One function of a Li-ion battery EMS or BMS is to prevent over discharge. > Once any battery cell reaches the lower limit, the battery will turn off. > For many systems, once charge current is again detected, the battery will > turn on. Some will not and require a user to turn the battery back on. You > can also install an external LVD device to stop power use at a higher SoC. > > As wrenches, its our responsibility to know our product and educate the > customer. Too often, this does not happen. > > Larry Crutcher > Starlight Solar Power Systems > > > > > > > On Feb 27, 2018, at 7:11 AM, drake.chamber...@redwoodalliance.org wrote: > > Snow on the array could be a very big problem with the heater load, > inverter idle current and anything else that might be left on. Extended > periods of heavy clouds can reduce power generation to be less than > system's internal losses. It seems like a pretty big gamble to leave an > expensive battery bank unattended, that can not go below freezing, and is > dependent on array power to prevent freezing. > > If AGMs survive in this application, it might be better to stay with this > technology. > > > ----- Original Message ----- > From: offgridso...@sti.net "RE-wrenches" > <re-wrenches@lists.re-wrenches.org> > To:"RE-wrenches" <re-wrenches@lists.re-wrenches.org> > Cc: > Sent:Mon, 26 Feb 2018 10:36:29 -0800 (PST) > Subject:Re: [RE-wrenches] heating a lithium battery bank > > > Hello Daniel, > > I will give this some thought. What lithium make? The ones I have looked > at log the temperature for warranty so that might negate the value a bit. > The high temp is just as bad in your case here. > > Since this has been working well I am assuming snow on the panels is not > an issue? > > Building a battery box that was cooled (small fan) from conditioned space > is what I have done. The wall between the garage and living space is > perfect. This won't help when the house is cold (unattended) much. It > won't help if the house is allowed to get hot either. > > Some of the Lion batteries are actually listed for living space. The LG > is. I don't do that with mine though. Hmmm > > Dave Angelini Offgrid Solar > "we go where powerlines don't" > http://members.sti.net/offgridsolar/ > e-mail offgridso...@sti.net > text 209 813 0060 > >> Hello Wrenches, here is a fun one for you all. >> >> >> >> The client you all helped me with earlier this year is now considering >> changing out their AGM off grid bank with a lithium battery bank before >> the >> next winter. I looked into this, as we have been eying the various >> lithium >> options for 2+yrs now, but not bit the bullet and really designed a bank >> into a system. >> >> >> >> The main issue I am trying to consider is this. The cabin is not >> occupied >> during most of the winter, and the batteries are in the unconditioned, >> but >> attached, garage. They drain the plumbing system and shut off all >> breakers >> except the ones that power the internet, chest freezer, and security >> system. >> As such, the battery bank has routinely gotten below freezing, sometimes >> staying there for 1-2 weeks. This is not an issue with AGM's, within >> reason. >> The battery bank has never gotten below 20F over the last 2 winters, >> where >> the site has seen below zero temps for brief periods. But the AGMs >> likely >> produce more heat during a charge than lithium's, and they have >> significantly more thermal mass to ride through the really cold nights. >> >> >> >> Lithium batteries, to the best of my knowledge, can be below freezing >> during >> storage. But to safely charge, they must be above 32F. So the thought >> was >> to >> provide an insulated battery box, and design in some small heating >> system >> that is set to 40-45F. The first thought was a low power fiberglass >> heating >> pad like is sometimes used for livestock to give them a slightly warmed >> place to lay down. Then tie that to a thermostat with a sensor on the >> battery bank. I would of course need to try to account for the extra >> load >> in >> the battery bank sizing. They array is more than is needed right now so >> I >> do >> not worry about it's ability to compensate when the sun is shining. >> >> >> >> In theory this could be ok, but I worry about the summer. Will the >> insulated >> enclosure cause the opposite issue during the summer, the batteries >> getting >> too hot? I have seen the AGM bank go to 110F at one point in Aug 2016. >> But >> with the lower internal resistance of the lithium's, maybe this is less >> likely to be an issue. Do any of you wrenches have any experience with >> this >> unconditioned setup? >> >> >> >> With Regards, >> >> >> >> Daniel Young, >> >> NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90 >> >> _______________________________________________ >> 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 >> >> > > > Dave Angelini Offgrid Solar > "we go where powerlines don't" > http://members.sti.net/offgridsolar/ > e-mail offgridso...@sti.net > text 209 813 0060 > > _______________________________________________ > 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 > > > _______________________________________________ > 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 > > Dave Angelini Offgrid Solar "we go where powerlines don't" http://members.sti.net/offgridsolar/ e-mail offgridso...@sti.net text 209 813 0060 _______________________________________________ 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
