Are Lithium batteries domestically viable ?

Options
spacebass
spacebass Registered Users Posts: 87 ✭✭
in Solar Beginners Corner #1
It seems to me that because of the set up skills required, even Solar controller manuals refer to 'the engineer' determining some set parameters, I cannot buy brand new Lifepo4 cells and separately buy brand new BMS controllers that I can see how they should be wired correctly, and install them myself , because the 'balancing act required' cannot be achieved by the controller's themselves but require the installer to have a deep understanding of the physics of Lithium technology ?
Is this correct ?
Tagged:
· Share on Twitter

Comments

  • Raj174
    Raj174 Solar Expert Posts: 795 ✭✭✭✭
    #2
    Options
    @spacebass
    A balancing BMS is not necessary to set up a LiFePO4 battery bank. What is necessary is that time is taken to accurately top balance the  cells in parallel prior to setting up the bank. What is highly recommended is a BMS that will display individual or parallel cell voltage and be able to communicate a shutdown to the charge controller or the inverter when either individual cells or the battery bank goes outside of a preprogramed voltage range.

    My LFP bank, 195AH @ 54.4V nominal has been in service for over three years. I use a JLD404AH Intelegent Amp Hour Meter to monitor high and low bank voltage to shutdown the system if necessary. I check individual cell voltage periodically because LFP cells are very stable when charged and discharged at sub C amperage rates. I rebalanced my bank after 2 years 7 months to add a 17th cell in series, however they can manage several years without rebalancing. Experience has taught me this. The initial balance is critical to this and time needs to be taken to do it correctly. It can take days and impatience can create the need for early rebalancing.  

    Rick
    4480W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
    · Share on Twitter
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #3
    Options
    Solar controllers are designed primarily to charge lead acid batteries, they can be used for lithium batteries but there are a wide variety of chemistries each with their own set of charging requirements. For this reason it's best to ask the battery manufacturer for the information pertaining to the charging and dischargeing, and build within the specifications.

    One can absolutely buy cells, a suitable BMS and build a battery, having a sound understanding of electrical theroy, particularly DC, will be an asset. The charge controller needs to be programmable, preferably a quality brand which allows custom settings, thus allowing setpoints to be programmed outside the common lead acid  algorithms.

    By "ballancing act" I'm assuming the ballancing procedure, in most cases this is done before assembly of the final topography. Some BMS systems have ballancing however that is to maintain ballance rather than to do the initial ballance.

    The alternative is to use drop in replacement type Lifepo4 which have an internal BMS and are pre ballanced by the manufacturer, they do cost more though.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
    · Share on Twitter
  • spacebass
    spacebass Registered Users Posts: 87 ✭✭
    #4
    Options
    I am seeing 'Active balancing' BMS for sale.
    · Share on Twitter
  • softdown
    softdown Solar Expert Posts: 3,825 ✭✭✭✭
    #5
    Options
    For some a major issue with lithium batteries is high toxicity of many, perhaps most, lithium battery fumes. A California fire department recently decided they had to replace all their fire hoses, and some other equipment, after dealing with a lithium battery fire in a house.

    Then the "press went dark". Lithium has major investors...   

    Seems that lithium battery banks tend to made of hundreds of laptop cells. With that many cells it is almost expected that there will be failures. I think Tesla "basically uses fuses" on each one? Something like that? 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
    · Share on Twitter

Categories