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Quality assessment of energy bank

Discussion in 'General Electronics Chat' started by Duck20, Nov 28, 2017.

  1. Duck20

    Duck20 New Member

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    Hello everyone, I have a small problem. I have such a bank of energy from a Chinese company, I am worried about some of his performance quality. Energy Bank has parameters 51.2V and 66Ah, rated discharge current 70A. This is LiFePO4 cells.
    I added a couple of photos from inside, it worried me that all the connections are so exposed and small diameter of the wires. The system has the ability to check the cells temperature there is 16 and they are connected in series are they balanced? There are some wires connected but it is hard to say whether it is from temperature measurements or from balancing. What do you think about all this?Are those cells that are loaded at about 1C in general need balancing? Are there any big mistakes?
     

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  2. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Why did you buy it when you know nothing about it and its manufacturer also might know nothing about it?
    Has anybody reviewed it or tested it? Are the parameter spec's and ratings a lie?
     
  3. Duck20

    Duck20 New Member

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    Nobody tested this before. I bought just to check this quality. The cost of one such battery is not a big deal for me. I would like you to answer my concerns. I would like to buy a lot of such energy banks so one for the test is not bad. The manufacturer gives information about 2000 cycles of charge, but what I think for this type of cell will be like 800 right?
     
  4. dave

    Dave New Member

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  5. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    1) Balancing does not require large diameter wires, nor does temperature measurement. I suspect they are for balancing, but there is no way to tell from simple visual inspection what a wire does. The fact that the small wires are connected to terminals rather than physically attached to the outside of a cell leads me to think they are for balancing. There may also be wires for temperature measurement, but your pictures do not allow that assessment.

    2) Your image of the rear of the pack shows clearly bus bars attached to terminals. I suspect those are for high current and connect the cells (mostly) in series. Pictures of the front of the pack are less clear, but are consistent with that. There are also larger gauge wires that seem to go to the high voltage ends of the series-connected cells.

    3) At such low voltage, exposed bus bars are not a concern. Moreover, the exposed connections are in a protective case. That is standard construction, for example, for welders.

    John
     

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