I calculated the height object height, Distance to the base of the object, Drone weight, maximum and minimum battery voltage, resistance force and power ($P$). The drone is flying in steady state, without acceleration and flying on a straight trajectory. I started looking for formulas on the Internet and came across this one:
$U_{max}=U_{min}−\frac{Q_{max}}{C}$
$Q_{max}$ is the maximum charge of the battery that it can give from a fully charged state to a fully discharged one. And the problem is that I can't find the formula for $Q_{max}$. The formulas I found were through the minimum battery capacity $C$. I may be an idiot, but I'm trying to fix it.