Announcement

Collapse
No announcement yet.

LFP equal to 48V 210ah (split thread)

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • LFP equal to 48V 210ah (split thread)

    So, not to jack the thread. I have a couple of smaller packs I made from the old 23650 A123 cells but how is this cell here rated http://store.evtv.me/proddetail.php?prod=CA180
    I was trying to figure out the cost to approx. equal my present FLA 48V 210Ah battery bank in terms of storage capacity. I would need what...16ish of these things in a series string to put together a single string that was closer to my inverter shutoff voltage (60.2V I believe).
    Last edited by Mike90250; 05-18-2015, 11:42 AM.
    1150W, Midnite Classic 200, Cotek PSW, 8 T-605s

  • #2
    You did "jack the thread" and i moved it to it's own thread so as to not confuse the real new newbie
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

    Comment


    • #3
      I will try to help you out. The answer is not that simple. First you need to know the application because each application has its own unique set of demands and requirements.

      Example in an Electric Vehicle due to extremely high discharge rates coupled with Peukert Law it takes 100 AH AGM battery to equal roughly a 30 to 35 AH LFP battery. So for now I am going to assume you are talking about off-grid solar.

      I am going to assume you will use the same 5 day autonomy design you would use for Lead Acid designs yielding 3 day usable reserve capacity to 50-60% DOD of a FLA battery. For maximum battery cycle life you want to operate a LFP battery between 10 and 90% SOC. To apply KISS analogy let's assume you will use 1 Kwh per day. That requires a 5 Kwh FLA battery which gives us 3 Kwh usable. That means it would take a LFP battery 3 Kwh / .8 = 3.75 Kwh. Now we have the ratio, and we can now make a simple KISS rule of thumb.

      It takes 3.75 Kwh of lithium to = 5 Kwh of FLA.

      or

      Rule # 75: 75 Amp Hours LFP = 100 AH of FLA.

      Keep in mind that discharge rates are assumed to be C/20 or higher, and temps are room temps. . If you discharge at a higher rate Puekert Law comes into play, or temp extremes drastically changes things.
      MSEE, PE

      Comment

      Working...
      X