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I need to implement an algorithm to know the capacity of a battery. I don't want to use any external gauges which are available on the market.

  1. Can you suggest which algorithm(s) is/are popular?
  2. Can we implement any algorithm ourselves?
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There is as far as I know:

  • Coulomb Counting, where you integrate the current, flowing into or out of the battery.

  • Voltage Measurement, where you measure the voltage of the battery

  • IT - Impedance Tracking,

  • CEDV - Compensated End of Discharge

Point 3 and 4 are found with TI Chips bq-something.

I know a lot of older E-Bikes use coulomb counting and OCV measurement in parallel, where CC is the primary gauging and OCV a backup verification process.

CC consists of the actual coulomb counting algorithm and a teaching algorithm, which calculates the Full Charge Capacity based upon End of Charge Voltage and End of Discharge Voltage.

Edit: Cheap chinese manufactured batteries only rely on Voltage measurement, although this method has a large margin of error, depending on the load.

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  • \$\begingroup\$ thank you alexander ,can we implement ourselves without any ic's in any microcontroller? \$\endgroup\$ – mani Oct 5 '18 at 9:57
  • \$\begingroup\$ @mani CC and Voltage you can implement yourself, you only need one or more ADCs. \$\endgroup\$ – Alexander von Wernherr Oct 5 '18 at 9:58
  • \$\begingroup\$ @mani For the Voltage measurement type you need the discharge curve of the battery, you can receive it from your supplier (normally) \$\endgroup\$ – Alexander von Wernherr Oct 5 '18 at 10:00
  • \$\begingroup\$ which algorithm is more accurate and why ? \$\endgroup\$ – mani Oct 5 '18 at 12:30
  • \$\begingroup\$ @mani Don't ask new questions as a comment, create a new question or edit the existing question. \$\endgroup\$ – Elliot Alderson Oct 5 '18 at 12:47

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