Originally Posted by
hotrod87
That is your low voltage detection working.
That is correct. Have you checked to see what your low voltage cutoff is set at? for 2Cell it should be 3.0 or 3.2 per cell(6-6.4V total).
This is built into the esc to tell you it's time to stop running before you over discharge your battery and possibly damage it.
The LT4 comes with a USB connector and you can download the software for free to update and check your settings.