[QUOTE=V-rex;9434003]I didn't express the question well. It's the other way around: Does the range of the transmitter depend on the strength of the battery? If so, it will gradually decrease over time as the battery ages. Or, alternatively, does it operate at full power up to the point it can't operate any more? Obviously the latter is the preferred scenario if they're mounted relatively far apart. Otherwise you're going to be replacing a lot more batteries.[/QUOTE
Usually the output is a certain amount, not entirely dependent on the battery voltage, until the battery voltage gets below the design parameters of the circuit. Then it will just stop putting out a signal altogether. Bottom line is, hook it up and try it. If it works, it works. If it is erratic, then you need to move the receiver closer to the transmitter.