Battery setup 1P or 2P same Mah Please share your opinion

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  • keithbradley
    Fast Electric Addict!
    • Jul 2010
    • 3663

    #16
    Wow...what a confusing thread...plenty of misinformation.

    Bottom line:
    If both setups are the same capacity, and discharge at the same rate (comparatively live up to the C rating claims), you won't see a lot of difference between the two. The difference you will see will be related to the difference in cell quality and internal resistance, not the wiring. Two packs paralleled does not increase resistance due to wiring! In order to believe this, you would have to believe that larger gauge wire increases resistance over smaller gauge wire (which of course is not the case). Electrons will always follow the path of least resistance. Adding an extra path DOES NOT increase resistance, it lowers it...in the same way that adding lanes to a highway will decrease resistance in traffic flow and allow more traffic to travel down the road without increasing the rate at which it's traveling (rate would be voltage in this example). I'm not sure how anyone could assume that adding another route for electricity to flow would increase resistance...this is really simple stuff...if you think of it in simple terms, it makes perfect sense.

    In the case of series connecting your lipos, you're not providing an alternate route for energy, you are adding to the path in which it has to travel. In this case, resistance is increased. These are the wires that you want to keep short. When you calculate wire length for your Schulze ESCs, do not count additional parallel wires. Only wire inside the pack for series connections, series connections between lipos, and the wire from pack(s) to ESC are relevant.

    I would personally buy the 5000mah or 6000mah lipos, but not because I think one will have a distinct advantage over the other. I would do it this way because the packs are more versatile and can be used in other applications, and because in the event of a cell failure, there is less collateral damage (Only one 5000mah pack would have to be purchased, instead of an entire 10,000mah pack)
    www.keithbradleyboats.com

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    • nata2run
      customcfparts.com
      • Nov 2011
      • 1837

      #17
      Hey Ryan, True this is getting a bit confusing over all. Keith has a good point. We talk a lot, and I have an idea about your main concern. I also know that you don't want to push your gear to the limits. Its possible that the demand on power you need won't be too high compared to its potential. In other words, if you want to run "12s" per motor, you should do a test say with 12s 6000mah -8000mah as a minimum and do some logging to see what the system requires in Watts, amps or which ever way you want to log. How you get to 12s (6000mah and above) is entirely up to you. 8s pack plus a 4s pack or x2 6s packs or x4 6s packs (2 in series and then into parallel to make up 12s 2p at the required ma/h). Better would of cause be if the "single cells" are exactly the same so they discharge evenly at the same rate. The "C" rating and quality of packs will be more important when you require "more power" than a standard battery can deliver. The more "crazy" you go, the more the system demands, and the more you have to speculate how you setup the entire system. At 44.4v a standard Lipo should be able to deliver 5550W if rated at 25c (that's 12s 5000ma/h 25c) then you can work it out from there, at 12s 2p its 11000w and so on ... 12s 2p 5000ma/h at 50c should be able to deliver 22,000w. Again those are just numbers, and can be different if the packs are not up to it. Having packs capable of a burst discharge of 100c should be able to produce over 40,000w for a short period
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      • Xcesive8
        Senior Member
        • Jul 2009
        • 395

        #18
        Hey All,

        Thanks so much for coming in here and sharing all the info.
        Even if there is mixed opinions, its good everyone gets to lay out there thoughts and hear one anothers ways of looking at it.
        Much appreciated.

        Kent your right, you know from us talking on the phone.
        I dont want to flog the living daylight outa this big girl, just want all my Electronics to be of a high standard, to atleast lesson the chance of component failure..
        I will be starting with small props 60mm's for first test.


        Ryan

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