Battery scheduling of microgrid

I want to optimize the cost of microgrid which contains few diesel generator and energy storage. The cost function of diesel generator is quadratic (non-linear) and battery cost function is also non-linear.

battery_cost(t) = ((b_price)/(b_cap*dod(t)*lifecycle(t)*eff))+0.5*Pb_dis(t)*x_dis(t)

The objective function is

battery_cost(t)+gen1(t)+gen2(t)+gen3(t)

I am trying to use fmincon for non linear optimization. I need use your suggestions how to use fmincon for this purpose as I am confuse should I use the gen1 as variable or the power dispatched by gen1. Kindly need your valuable answers