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How to wire a Lithium Battery Pack Q

  1. Apr 18, 2016 #1
    hi all,
    i am embarking on a new project, building a outdoor rolling credenza that has TV (with air operated TV lift), cd player, small receiver, 100% wireless (power and wifi, etc).

    my design calls for a battery pack that can deliver approx 5x106 joules, this leaves me in the ballpark of 12v@115Ah, or 48v@29Ah
    in general this is 200watt x 6hr @ 85% system efficiency.

    true sine wave inverters run best at 48vdc, but a 12v inverter can also work.

    (12v inverter) can i run 12v Lithium batteries in parallel if they are isolated via diodes and the charger has four independent cell chargers,
    or, four 12v Lithium batteries in series for 48v (can a 4 cell charger straddle each cell in series and be ok?),
    or do i source one 48v ~29Ah battery

    any suggestions?
  2. jcsd
  3. Apr 18, 2016 #2
  4. Apr 18, 2016 #3
    hah, i will need a short cord, but it will likely be mounted to the rolling cart via a wind-up mechanism, so that when not in use i can plug it in to charge the batteries.

    its a project, a completely wireless project, including wireless power, wifi, and Miracast. having a cord laying across my back patio as a tether is the old way, this is the new way. if it goes well, well, it might be my 2nd job fab'ing complete solutions like this, etc.
  5. Apr 19, 2016 #4
  6. Apr 19, 2016 #5
    i am looking for just the batts, and ideas about design. 4 12v in parallel vs 4 12v in series vs 1 48v
    delivered energy has to be around 5x106joules, but i am not 100% sure if i need some headroom in there because the 200w inverter i am looking at does a shutdown at 10.5v or 42v (12v vs the 48v model, etc).

    can i extract that much energy from a 48v ~29Ah batt, or four 12v ~29Ah batts w/o the batt voltage reaching shutdown threshold of inverter?
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