That is a "lie" the BMS is telling you. When the BMS reports zero, there is always a certain percentage of power left in the battery. Often around 20%. This is because a battery under 20% (or a similar amount) can be dangerous.
My understanding is that some manufacturers do the same thing at the top side as well, but I don't have a specific example (except that when one turns on the limit charge to 85% on Android, it actually starts reporting 85% as 100%) What the companies which say that you can discharge to zero are actually saying is that their battery has X amp hours before the BMS will shut the battery down. So yes, if you have a 80ah battery that you can discharge to zero, you'll likely find 100Ah of energy in the battery... you just can't access the last 20%. All based on the specifics of the cells used in the battery. If instead, you have a battery manufacturer who wants to engage in specmanship, they'll call it a 100Ah battery but neglect to tell you that 20% of that isn't accessible. Like I said in the last message, the exact percentage of energy left at empty is going to vary. It's just never 0%. On Fri, Apr 26, 2024, 3:27 PM TJ Trout <t...@voltbb.com> wrote: > Not to mention you get twice the capacity because lifepo4 can take 0% > depth of discharge without damage > > On Fri, Apr 26, 2024, 1:26 PM Mike Hammett <af...@ics-il.net> wrote: > >> I've been an AGM guy, but the last quote we did, it was about $777 for >> just the AGMs and $900 for LiFePO4 with everything in a neat and tidy >> rack-mount box. >> >> >> >> ----- >> Mike Hammett >> Intelligent Computing Solutions <http://www.ics-il.com/> >> <https://www.facebook.com/ICSIL> >> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> >> <https://www.linkedin.com/company/intelligent-computing-solutions> >> <https://twitter.com/ICSIL> >> Midwest Internet Exchange <http://www.midwest-ix.com/> >> <https://www.facebook.com/mdwestix> >> <https://www.linkedin.com/company/midwest-internet-exchange> >> <https://twitter.com/mdwestix> >> The Brothers WISP <http://www.thebrotherswisp.com/> >> <https://www.facebook.com/thebrotherswisp> >> >> >> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >> ------------------------------ >> *From: *"Ken Hohhof" <khoh...@kwom.com> >> *To: *af@af.afmug.com >> *Sent: *Friday, April 26, 2024 2:01:22 PM >> *Subject: *Re: [AFMUG] DC power supplies in parallel >> >> I tend toward a minimum of AC/DC power supplies, and fuse blocks or DC >> breakers for the loads. But the other network engineer I work with prefers >> a dedicated PSU for each load. So you may not get a uninamous >> recommendation. >> >> Note I tend toward DC sites and other guy sees that as unnecessary >> expense and hardware. So if you are doing AC sites, maybe don't listen to >> me. >> >> And I'm still using AGM batteries while all the cool kids are using >> LiFePO4 with BCMs, so definitely don't listen to me. >> >> ---- Original Message ---- >> From: "Steve Jones" >> Sent: 4/26/2024 1:49:48 PM >> To: "AnimalFarm Microwave Users Group" >> Subject: [AFMUG] DC power supplies in parallel >> >> I have a bunch of various meanwell 48 vDC power supplies mostly 120 and >> 350 watt models with most loads being 45wattish and some 108wattish. >> >> One site im re-cabling has 1100w in PSUs taking a ton of space providing >> for a total demand of around 440w. Seems overkill and only accounts for the >> DC direct powered stuff, not the other 300w or so >> >> Whats the consensus on an AC powered site? individual PSUs for ever >> equipment. Big PSU/rectifier for all? >> Our battery capacity at this particular site is on the APC at the base >> providing just AC to the top, we are not bringing the batteries up for >> reasons and all electronics are up top. >> >> >> >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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