Low battery voltage
Poor connection in battery circuit (The first suspects are the battery terminals and the next are the ground, then hot connections at the other end of the cables finally every connection between the battery and the power distribution panel)
Next Normal FULL CHARGE battery voltage is 12.6 (comment follows)
Chargeris 13.6 to 14.6 depending on state of charge.
I have a 2-way radio that WILL NOT OPERATE properly on voltages less than 12.7 or so it seems (not measuring when on car battery power) works great on 14.2 Volt LiFePo4 pack I have for it.. in fact last Saturday I did some testing and the radio hit full power (100 watts out) into the test device and when I switched to the antenna Talked from Flint, MI to Phoenix AZ like he was next door.
Your slide. like my radio, is voltage sensitive.. As voltage goes down the current goes up. At some point (Pre-set point) the controller thinks "All Done motor stalled" becuse when the motor stalls the current goes up. That is the "limit Switch" on many slides.