mirror of https://github.com/ArduPilot/ardupilot
63 lines
1.8 KiB
Markdown
63 lines
1.8 KiB
Markdown
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# Battery State of Charge Estimator
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This script implements a battery state of charge estimator based on
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resting voltage and a simple LiPo cell model.
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This allows the remaining battery percentage to be automatically set
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based on the resting voltage when disarmed.
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# Parameters
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You will need to start by setting BATT_SOC_COUNT to the number of
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estimators you want (how many batteries you want to do SoC estimation
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for).
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Then you should restart scripting or reboot and set the following
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parameters per SoC estimator.
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## BATT_SOCn_IDX
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The IDX is the battery index, starting at 1.
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## BATT_SOCn_NCELL
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Set the number of cells in your battery in the NCELL parameter
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## BATT_SOCn_C1
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C1 is the first coefficient from your fit of your battery
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## BATT_SOCn_C2
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C2 is the second coefficient from your fit of your battery
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## BATT_SOCn_C3
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C3 is the second coefficient from your fit of your battery
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# Usage
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You need to start by working out the coefficients C1, C2 and C3 for your
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battery. You can do this by starting with a fully charged battery and
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slowly discharging it with LOG_DISARMED set to 1. Alternatively you
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can provide a CSV file with battery percentage in the first column and
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voltage in the 2nd column.
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Then run the resulting log or csv file through the script at
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Tools/scripts/battery_fit.py. You will need to tell the script the
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following:
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- the number of cells
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- the final percentage charge your log stops at
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- the battery index you want to fit to (1 is the first battery)
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That will produce a graph and a set of coefficients like this:
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- Coefficients C1=111.5629 C2=3.6577 C3=0.2048
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Use the C1, C2 and C3 parameters in the parameters for this script.
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The remaining battery percentage is only set when disarmed, and won't
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be set till 10 seconds after you disarm from a flight.
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