Introduced low side current sensing to solar panel which works better than I expected. For voltage measurements I have realized pic's analog input pin is leaking a lot more than expected thus resulting lower voltages than it should. It's seems the voltage dividers input impedance is too much for analog input. Well at the same time I don't want to lose any precious current from voltage divider. Will work on a voltage buffer from op amp later.

Next I will throw the mosfet IRLD120 in start cooking mppt.

Panel and battery voltage. After 11:09 panel disconnected from battery and you can see how the voltage jumped. Diodes voltage drop is also pretty visible.

Current measured from solar panel during a few tests