i dont understand how in his schematics it works because its not connected to the micro so there is nothing to tell the solar panel to charge the battery.
I don't fully understand either. The only clues we have are: "The charging relais is a bistable. That means it holds its position even when powered off. This way, all the power from the solar panel goes into the accu and no power is wasted on the relais." and "The battery is loaded when the voltage gets lower than 12 V until it reaches 14.2 V again."
So it looks as though he simply checks the battery voltage and if it is below 12V then the 'set' coil of the latching relay is energised to close switch K1 and connect the solar panel directly to the battery. He does not check to make sure the solar panel actually has a high enough voltage to charge the battery, nor does he limit the charging current in any way. When the battery voltage reaches 14.2V he energises the 'reset' coil of the relay to open switch K1 and disconnect the solar panel.
Regarding the light sensor, that clarifies things. However, pin
9 of the micro isn't shown as an
analogue input (only pins 1,2,6,7 are). Make sure you use an analogue-capable input of the picaxe.
Where you have circled the connections is not as per my circuit. You have both gates connected to the tops of the resistors, i.e. to +6V. The gates should connect to the
bottoms of the resistors, i.e. Q2 gate>>R6, Q3 gate>>R5.
Edit: The voltage regulator is still shown as unsuitable LM323.