Never heard of that, but if that did exist it would not be very smart as it would result in more battery use to send that signal, resulting in that almost dead battery to get drained even faster.
I would imagine the remote has a driver chip that checks the voltage and if it does not meet a certain threshold, it will send the signal to the car to let you know. However, I'm just speculating.
Old Car: Chevy Cobalt 2006 LS Sedan base (Automatic)
New Car: Chevy Impala 2011 LT Fully Loaded (Automatic)