Current signal at 0

Good morning

I would like to know the consumption of my plane during the flight. I see in the log file there is many signals for the battery. The current for the battery voltage is good but the current is always at 0 (same for the discharge). I use a Lipo 3000mAh 3S 11.1V.

For example a log file : https://logs.px4.io/plot_app?log=d3e2b95b-e0d3-4f68-bb6f-25819a9e8ef0

Please someone know how to recover the current ?