I have an interesting project and I don't know whats the best solution.
Basically I have a charger (charges one battery at a time) and 2 batteries.
What I want to do is to have the charger charging battery 1 (while battery 2 is feeding clean power to an audio system)
With a voltage sensor (when battery is low) , I want to switch the charger to battery 2 and have battery 1 power the audio system. (the voltage sensor its not the question)
My question is : The battery that feeds the audio system must be completely isolated from the charger and ground (so no power noise is present).
Is there a way (except SSR) to do that ? PCB is quite small and space is at a premium. Also take in consideration and charger is 3A 5.5v and batteries are 5.4v