Hi I am currently trying to use two batteries (individually) operating at about 1 volts to power my circuit, the trick I need to figure out is how to switch between batteries when the first battery drops below . 7 volts so the second battery which is at 1 volt can now power the circuit.

Thanks,

Nathan

 

Is there a reason you don't just put them in parallel? Anything else will not last as long.

 

Two LDO regulators where ones enable is the others disable and that is driven by BJT (ideal for 0.7V detection). Once BJT stops being biased enough it could switch to enable.

Make sure you have enough capacitance for switch over and be mindful of the fact you have super low voltages and not much likes to run @ 1V but I guess now a days there might be enough options for you with low voltage circuitry.