BEST - Battery SOC estimator
The LYNX firmware includes the BEST module to estimate the battery SOC (State Of Charge). LYNX uses the 4-point OCV model — the cell OCV curve is approximated by 4 voltage breakpoints, with a single scalar cell resistance.
The BEST parameters are located in the /best folder.
Parameters
S
Number of cells in series.
P
Number of cells in parallel. Set to 0 to disable coulomb counting.
If the siliXcon controller is not the only power device connected to the battery, coulomb counting should be disabled since the controller cannot measure the total battery current.
soc_gain
SOC voltage correction weight. Set to 0 to disable voltage correction during run (voltage correction will still work during BEST reset).
reset_time [ms]
SOC reset time at device startup. Negative value for manual-only reset via the breset command. Set to 0 to disable the reset feature.
reset_gain
SOC reset correction weight. Same role as soc_gain, but applied during the BEST reset period.
Rs [Ohm]
Pack wiring resistance.
Cc [mAh]
Cell nominal capacity.
Rc [Ohm]
Cell nominal resistance.
OCV breakpoints [V]
The cell OCV (Open Circuit Voltage — the voltage on a single battery cell without load) curve is defined by 4 breakpoints:
States
| State | Unit | Description |
|---|---|---|
SOC | 0-1 | Battery state of charge |
Permanents
Located at folder /permanents.
| Permanent | Unit | Description |
|---|---|---|
Cmax | mAh | Maximum battery capacity (at 100% charge) |
Cact | mAh | Actual battery capacity |
Shell commands
| Command | Description |
|---|---|
breset | Reset the whole BEST algorithm — SOC and SOH. During reset_time, SOC is corrected using reset_gain |