avoid using 7805 as a regulator, masyadong aksaya 'yan sa efficiency. batteries should be connected right after the panel (with battery charger), tapos sa battery kukuha ng load. kung 10V lang, pwede na 'yung bank ng 6V SLA as they will be the cheapest.
BTW, solar tracking normally doesn't have any feedback dahil fixed ang cycle ng araw based sa kalendaryo kaya typically isang ikot lang from sunrise to sunset tapos balik lang sa reset position.
taken from Wikipedia on Heliostat:
"Most modern heliostats are controlled by computers. The computer is given the latitude and longitude of the heliostat's position on the earth and the time and date. From these, using astronomical theory, it calculates the direction of the sun as seen from the mirror, e.g. its compass bearing and angle of elevation. Then, given the direction of the target, the computer calculates the direction of the required angle-bisector, and sends control signals to motors, often stepper motors, so they turn the mirror to the correct alignment. This sequence of operations is repeated frequently to keep the mirror properly oriented."