Cell balancing refers to the process of maintaining an equivalent amount of charge in series connected cells (string). A pack can be considered balanced if all the series-connected cells are at the same state of charge (SoC) when the pack is fully charged. Balancing is a charge management process performed by the battery management system to ensure the pack is balanced, and that no cells are overcharged or over discharged in the process.
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There idt there is no a good way to balance cells that are connected in parallel. The best thing to do there is to characterize and sort the cells well. |
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Which would be on the same order of magnitude as the measurement inaccuracies of the IC they used, so it wasn’t significant to alter the voltage readings. Additionally, as the balancing current would be constant, there would be no transient effects associated with it. Allowing for voltage to be measured in parallel with the balancing current allows for easier software coding, as the algorithm for determining how long to discharge the cell (before stopping and taking a measurement and so on) wouldn’t be needed, although they would still have measured at a certain time interval no matter the solution.
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In general, it seemed like it was just a little simpler on the software side with 2 wires, at the expense of a couple hours of wiring and extra points of failure. Take that how you will (probably not worth it to use two taps?).
Note: The LTC6811 ICs can do that balance current shut-off automatically.
Nuvation Energy’s Balancing Capabilities
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