RTL on Voltage or Current issue - does it release?

I have voltage sensor installed w/o telemetry. I’ve considered setting RTL on low voltage, but wonder how I will recovery control of plane once it goes into RTL? How long will it stay in RTL? until the plane totally runs out of power, or will it allow me to control in manual once it returns to launch.

Assumption is that RTL includes infinite loiter once launch waypoint is reached.

An mode change via RC or GCS gives you control.