Low voltage alert

Mike Shellim 05 May 2018
updated 30 Sept 2021

One nice thing about OpenTx is that you can tailor your battery alerts according to their chemistry. The snippet below is a battery alert for 2S LiPo or LiIon receiver battery. It ignores low voltage spikes:

L1: a<x, RxBatt, 7V, Delay(3s)

SF1: L1, Play Sound(Beep 1), repeat(4s)

How it works:

If using a voltage sensor, use Cels as the first operand in L1.

Sound files

The example above uses a simple beep, but I'd recommend playing a sound file.

Most sound packs have lowbat and batlow; note however these provide only generic warnings, so I use my own "receiver battery low" sound file so there's no confusion about which battery is affected. Consider also using the Haptic action. You can specify this in a second special function.