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programming cc and connecting powerwalls?

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  • #46
    Originally posted by SunEagle View Post

    I am not sure if the product you are looking at can be wired in parallel. That is not saying it can't be done. I just don't know how to do it safely.
    It has been done safely using BMSs on each pack. In the case of used packs, there are issues of eddy currents between packs of different capacities but the current shunt on each pack will signal the BMS to take a pack offline if the current is too high or if the programmable HVD or LVD limits are set correctly.
    I do not think it is advisable with Pb, but there are battery isolation and charging devices for RVs that use similar processes. In those cases the devices are usually only in parallel for charging.

    I wonder how does Tesla does it with their Powerwall units?
    The powerwalls are wired in parallel on the AC side. Just like any hardwired device. They can be a load or a source of current.
    Last edited by Ampster; 05-22-2020, 03:56 PM.
    9 kW solar. Driving EVs since 2012


    • #47
      77242 the issu eis you went out and bought something in hopes you could make it work. You simply failed to do any homework. LFP batteries are parallel at the cell level, not pack level as you see below.

      Can you put parallel LFP packs in parallel? It is possible if the packs were designed from the ground up as stand alone units. Essentially each pack would have to have its own independent charger built-in only requiring an external power source like a standard power circuit. Or has to use a communication system to work with a Master/Slave arrangement. I can't tell you what they use, nor do I care.

      Here is what I can tell you. Pick a voltage and set every control in your controller to the same voltage to make it a Float Charger. Bulk = Absorb = Float = Magic Voltage you select.
      MSEE, PE


      • #48
        Holy **** Guys the “professional” actually provided some information about what I am asking, only Took 4 pages.