Ok, so here it is. Here is a quick description of how it operates.
The Lm358 op-amp and circuit around it is an oscillator. The oscillator is used to generate a voltage that is higher than the battery voltage, to "fool" the alternator. This higher voltage is fed to the Sense input of the alternator. The sense voltage is clamped to be 1,02V higher than the battery voltage by the 2 diodes marked in pink on the circuit.
This means that the alternator, in my case, will charge the battery until the sense input is at 14,42V. This 14,42V is what the factory internal regulator voltage wants to get. But because of the diodes in pink on the circuit, the battery voltage will actually be 13,4V when the sense input is at 14,42V. This difference is caused by the 1,02V drop over the pink diodes.
Now if I press my break pedal and the break lights comes on, the oscillator(charge pump) circuit stops working. This is done through any of many diodes in green at bottom of circuit. Everything is basically not working except for the diode at the top of circuit(HER508). This causes the alternator sense input to be 0,3V lower than the battery voltage.
Now suddenly the alternator sees the battery voltage is low and starts charging the battery at a fast pace. In my case it will charge the battery until the battery voltage is at about 14,72V. This draws more power from the engine and is used as a sort of regenerative breaking.
I have only 1 diode in the green highlighted area but you can add as many as you want, from a switch inside vehicle, maybe at night when your lights is on or switch when foot is off petrol pedal and vehicle in gear. As long as it gets the 12V in through the green diode the circuit will switch off and alternator will charge battery at higher voltage.
The circuit is only switched on when the car ignition is on. So it doesn't draw any current when car is switched off.
