BQ51013B: BQ51013B & BQ24040 setup for 1A current charge for 1800mAh Lipo battery

Dear TI support, 

My name is Joaquim Martinez and I am desiging a battery charger for a 1800mAh LiPo battery. 

For this I am using a QI BQ51013B and BQ24040 and my desired charge current is 800mA. The problem is that I can't never achieve the 800mA, the current is always arounf 350-400mA, even disabling the communication current limit setting QI EN2 to "1". According with the components descriptors of both datasheets, my setup and values are:

BQ51013B:

Coil: VISHAY IWAS-3827EC-50 (Ls:10.7uH and L's = 15.7uH aprox)

C1 (series capacitor): 103nF/16V. matched for 125KHz.

C2 (parallel capacitor): 2.47nF/16V. matched for 1MHz.

Ccomm_x = 22nF/25V

Cboot_x = 10nF/25V

Cclamp_X = 470nF/16V

EN1 = 0, EN2 = 1 (tied directly to REG output and to an external 5V)

TS_CTRL pin with 10k resistor to GND.

Rfod = 196R

Ros = 20K

R1 = 82R -> Current limit 1.1A, Imax = 942mA

C4 (Cout) = 10uF/16V

C3 (Crect) = 10uF+4.7uF/25V

BQ24040:

R_Iset = 680R -> charge current to 790mA

R_preterm = 2K

I have done several tests and I can't increase the charge current. My tests are based on two scenarios:

1. With the whole system: QI+charger+battery 

2. QI+variable load equipment (no battery and with charger isolated).

In the scenario 1, current is limited to 350-400mA, in the constant current phase, and Vout from BQ51013B is 5.07V. In the scenario 2, when I increase the load current, through the dynamic load equipment, when I reach the 400mA, Vout starts to fall to 4.5, 4, 3.5, etc. in the way that I increase the current charge. 

I tried to recalculate C1 and C2 to match them to 100KHz, but the problem is the same.

Since I am sure that the resistors for setting the current limits and operation of both IC are good, and EN2 is ok, I doubting about the coil, matching C1 and C2 values and max DC voltage of all capacitors connected to the coil. My doubts are:

1. According to the coil datasheet, it can works up 10W. This is the same power that a recommended coil in the datasheet (IWAS-4832FF-50). Is the size of my coil good for achieve the 800mA? I think yes, because in BQ51013B datasheet they are smaller coils.

2. The matching values are ok? Must I calculate the values for 100KHz or 125KHz?

3. How affect the DC rated voltage for C clamp and C1 and C2 that I am using (16V)?. Is this a problem? can explain my problem? 

4. Finally, how important are Cout and Crect values to achieve the 800mA?

Please, can anybody help me with this?

Thanks.

Joaquim.