Ok, I have been doing a little reading and looking at efficiency I can see LDO's can be as low as 30% efficient whereas switchmode is plus 90% efficient.
The whole reason I am regulating the voltage is because the input supply could be in excess of 15v, amongst other applications I want to run some LED lighting at close to full power, so I dropped to 10v for supply headroom as I can not have the LEDS supplied at say 15v or they will pop.
Am I over complecating this? I have 3 circuits so far, one a thermostat, 2 is a charge regulator 3 is a lighting circuit with LDR.
Would I be better regulating 12v for all circuits, possibly switch mode regulation