Jeff, I don't have answers to many of your questions but one thing I wanted to point out as that some lithium-ion manufacturers like Blue Planet underrate the capacity of their batteries so they can get to the 100% DOD without impacting cycle life. For example, Their 16 kWh battery is actually something like a 17.2 kWh battery. Whereas other manufacturers give you the actual capacity of the battery but suggest limiting the DOD to 80%. This makes it a bit hard to compare apples to apples.
Also from what I've seen the cycle life curve for 80% DOD or less with lithium-ion batteries is relatively flat. Thanks, Will -- *Will White* Curriculum Developer e: w...@solarenergy.org w: www.solarenergy.org p: 802-272-3092 NABCEP Certified PV Installation Professional # 093006-34 Do you envision a world powered by renewable energy? Be the change <http://solarenergy.org/donate>. On Tue, Aug 11, 2020 at 2:30 PM Jeff Clearwater < je...@villagepowerdesign.com> wrote: > Hey All, > > Great Thread - so does anyone have the missing cycle life information for > the Discover AES and Fortress Eflex below? > > > - Discover AES (42-48-6650) (Spec sheet does not list cycles) (but > does give 38MWh warranty > > see analysis sheet here: > https://aeesolar.com/wp-content/uploads/2019/02/DISCOVER-AES-The-AES-LiFePO-Battery-Solar-Off-grid-Advantage-20190124-AEE.pdf > > that sheet says "With a designed DOD of 50% lead-acid batteries are > expected to last ~1500 cycles or 4 Years of daily cycling. With the > Discover AES 10 Year 38 MWh Warranty, you’ll be half way into your 3rd Set > of lead-acid batteries." > > That would imply 5250 cycles under warranty - but surely it has more in it > than that for an expensive LFP! Can't find a reference anywhere. 38 > MWH/6.65 KWH = 5700 cycles - their own spreadsheet says "Cycle Life (@DOD > rating): NA" Impressive warranty but how much past the warranty they > don't seem to want to venture. It's the most expensive of the options > listed here (well comparable to BI) and comes with highest quality > recommendation and has great closed loop communications - but would love to > know the top end cycle figure. > > > - Fortress EVault (18KWH) (Spec sheet says 6000) > - Fortress EFlex (5.4 KWH) ( Spec sheet does not list cycles) > - Simpliphi 3.8 (spec sheet says 10,000+ @ 80%) > - Blue Ion 2.0 spec sheet says 8000 @ 100% DOD > > Does anyone know why Simpliphi and BI an claim such high cycle life > whereas Fortress says 6000 and AES won't venture it? same chemistry? so > is Fortress underselling or the other folks over selling? > Has anyone even seen a curve of cycle life vs. DOD for LFP? or is that > not so much a curve as a flat line? > > thanks! > > Jeff > > ~~~~~~~~~~~ > Jeff Clearwater > VillageLab > Village Power Design > www.villagelab.net > www.villagepowerdesign.com > cell - 413-559-9763 > ~~~~~~~~~~~~~~~~~~~~~~~ > > > > > Richard Scott wrote on 8/11/20 10:35 AM: > > Also keep in mind that the battery charge/discharge efficiency is much > higher for lithium batteries compared to lead acid. > > Richard > > > On Tue, Aug 11, 2020 at 8:17 AM Jay <jay.pe...@gmail.com> wrote: > >> Hi William, >> >> I dont do the math based on up front kwh cost, but on lifetime kWh based >> on the number of cycles per average DOD that are going to be used. I use >> this same formula to compare all batteries to each other. >> >> Jay >> >> Peltz power. >> >> For example, a Rolls L16 ex has 3500 cycles at 50% DOD, and it’s a 371 >> amp hr at 6v or 2.226 kWh >> Retail is $400 >> >> 3500 cycles x 1.1 kWh At 50 DOD=3850 kWh >> $400 / 3850 kWh = $.10 kWh >> 10 years of 50% cycling daily >> >> Compared to say a mid grade US battery, 1400 cycles to 50%, 400 amp hr. >> 2.4 kWh >> $325/1680 kWh = $.19 kWh. >> 3.8 yrs life >> >> Compare to say BI >> $1000 kWh roughly. >> If you get 10,000 cycles, that works out to same cost. $.10 per kWh. >> 27 yrs, but will the chemistry actually last that long? >> However, you have a massive upfront money cost. >> And for those of us off grid, you can’t really cycle 100%. And many >> lithium in the fine print don’t want you to charge to 100% daily. Let’s >> assume you start the generator at 10% and charge to 95%, now your usable >> amount is actually 85%, not 100%. >> Cost per kWh goes to $.12. >> >> >> >> >> On Aug 11, 2020, at 6:04 AM, William Miller <will...@millersolar.com> >> wrote: >> >> >> >> Friends: >> >> >> >> I am hoping y’all can tell me I am doing something wrong with my >> arithmetic. I have registered to purchase Blue Planet batteries and priced >> the product. I come up with math that indicates that comparing usable >> amp/hours to usable amp/hours, that the Blue Planet is 5 times the cost of >> a flooded L-16 battery array on a cost per kilowatt/hour. Can this be true? >> >> >> >> I am using these parameters: >> >> >> >> 1. DOD for flooded L16s: 50% >> >> 2. DOD for Blue Planet: 100% >> >> >> >> I hope I am wrong. >> >> >> >> Also, we often install battery arrays that are upwards of 4,000 AH. For >> example, we installed 5,668 of East Penn flooded batteries on a couple of >> projects. To acquire the same capacity in Blue Planet would require 9 >> cabinets (again 50% DOD versus 100% DOD). Is this correct design? Is it >> practical to install 9 cabinets? Does the system detect and compensate for >> circulating currents in this many parallel strings? >> >> >> >> Thanks in advance. >> >> >> >> William Miller >> >> >> >> >> >> *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On >> Behalf Of *Jerry Shafer >> *Sent:* Sunday, August 9, 2020 12:02 PM >> *To:* RE-wrenches >> *Subject:* Re: [RE-wrenches] Best Battery >> >> >> >> Wrenchel have been very happy with all my Blue Planet battery systems, >> best battery you will install. >> >> Jerry >> >> >> >> On Sun, Aug 9, 2020, 11:19 AM <drake.chamber...@redwoodalliance.org> >> wrote: >> >> Hello Wrenches, >> >> What is the best Li-Ion battery to use with an off grid system? >> >> Thanks, >> >> Drake >> Athens Electric >> >> -- >> _______________________________________________ >> 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://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> 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://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> 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://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> 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://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette:www.re-wrenches.org/etiquette.htm > > Check out or update participant bios:www.members.re-wrenches.org > > > -- > ~~~~~~~~~~~ > Jeff Clearwater > Village Power Design > linkedin <https://www.linkedin.com/in/jeff-clearwater-0622a312/> > www.villagepowerdesign.com > cell - 413-559-9763 > ~~~~~~~~~~~~~~~~~~~~~~~ > _______________________________________________ > 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://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > -- *Will White* Curriculum Developer e: w...@solarenergy.org w: www.solarenergy.org p: 802-272-3092 NABCEP Certified PV Installation Professional # 093006-34 Do you envision a world powered by renewable energy? Be the change <http://solarenergy.org/donate>.
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