Battery capacity percentage estimation

[hippo5329]

Battery capacity percentage estimation - Optional

The battery capacity percentage estimation in the /battery topic can enabled with the battery parameters. For Li-ion battery, the minimum voltage (empty) of a single cell is 3.0V typically, and the maximum voltage (full) is 4.2V. For 3S battery pack, the minimum voltage is 3.0V x3 = 9.0V and the maximum voltage is 4.2V x3 = 12.6V. The capacity of 18650 is around 2000mAh = 2.0Ah.

#define BATTERY_CAP 2.0 // battery capacity Ah
#define BATTERY_MIN 9.0 // battery minimal voltage
#define BATTERY_MAX 12.6 // battery maximum voltage

This is the /battery message of my 12.6V 4.9Ah battery pack.

header:
stamp:
    sec: 1716351874
    nanosec: 821621000
frame_id: ''
voltage: 12.357491493225098
temperature: 0.0
current: .nan
charge: .nan
capacity: 4.793232440948486
design_capacity: 4.900000095367432
percentage: 0.9782107472419739
power_supply_status: 0
power_supply_health: 0
power_supply_technology: 0
present: true
cell_voltage: []
cell_temperature: []
location: ''
serial_number: ''