Originally Posted by
gigaplex
You might be better off looking at radios with telemetry built in. I'd assume voltage level would be one of the available sensors.
That in itself may be overkill. Most ESCs should have a cutoff feature that will cut power when the voltage drops too low. There are also voltage alarms with LEDs and buzzers which may be sufficient. How much detail do you actually need?
I did see some of the alarms, and will probably get some either way. I will definitely want a live view stream to a monitor or phone so I figured if it was easy I would like to be able to see battery levels as well, but its not a huge deal.