Find minimum of variable by altereing two variables.

Hello!

I'm simulating an energy system and trying to minimize a variable by altering battery size and level of power consumption in an if loop. At the time I'm just altering the battery and level of power manually, but is there a way to alter them automatically to find a minimum?

See code if anything is unclear. It is "E_bat_max" and "Allowed_summer" I'm altering to minimize "overload".

for j = 2061:24:2880
  for i = (j):(j+23)
    E_load2(i) = E_load(i)+EV_load(i)-E_pv2(i); 
    if E_load2(i) < Allowed_summer
      if E_bat < E_bat_max
        charge = min(P_bat, (Allowed_summer-E_load2(i)));
        E_bat = min(E_bat + charge*eff, E_bat_max);
        E_load2(i) = E_load2(i)+charge;
        E_bat2(i) = E_bat; 
      elseif E_bat == E_bat_max
        E_bat2(i) = E_bat;
      end
    end
    if E_load2(i) > Allowed_summer 
      if (0 < E_bat) && (E_bat <= E_bat_max)
        charge = min([P_bat, (E_load2(i)-Allowed_summer), E_bat]);
        E_bat = E_bat-charge;
        E_load2(i) = E_load2(i) - charge;
        E_bat2(i) = E_bat;
      end     
    end
  end 
end
for i = time
  if E_load2(i) ~= Allowed_summer
    overload = overload +1;
  end
end