Simple command line utility to display charging (or discharging) rate in watts on linux. You might have to modify battery_directory and the status/current_now/voltage_now names based on laptop brand, but Lenovo, Dell and Samsung seems to use this convention.
#!/usr/bin/python3
battery_directory = "/sys/class/power_supply/BAT1/"
with open(battery_directory + "status", "r") as f:
state = f.read().strip()
with open(battery_directory + "current_now", "r") as f:
current = int(f.read().strip())
with open(battery_directory + "voltage_now", "r") as f:
voltage = int(f.read().strip())
wattage = (voltage / 10**6) * (current / 10**6)
wattage_formatted = f"{'-' if state == 'Discharging' else ''}{wattage:.2f}W"
if state in ["Charging", "Discharging", "Not charging"]:
print(f"{state}: {wattage_formatted}")
Output:
Charging: 32.15W
Discharging: -5.15W