Developing a battery switch-over circuit which is made of two lanes of the depicted circuit. Operation voltage range is from 3V. 12V. Only one lane should be enabled at a time which is governed by logic not included in the schematic. Each lane can (dis)connect its battery (V+) by means of two back-to-back p-MOSFETs (Vg, th = 1. 5V). The drivers
and switch-over circuitry are powered by Vs which is derived by OR-ing all batteries via diodes. Now I am concerned over the case when the Vs voltage falls below around 3V which comes close to the MOSFETs safe (2x Vg, th) gate threshold voltage and the TLC3702 comparator minimum operating voltage.