Sabertooth Dual 25A Motor Driver User's Guide
Lithium cutoff
Switch 3 of the DIP switch block selects lithium cutoff. If
switch 3 is in the down position as shown the Sabertooth
will automatically detect the number of series lithium cells
at startup, and set a cutoff voltage of 3.0 volts per cell. The
number of detected cells is flashed out on the Status LED.
If the number of cells detected is too low, your battery is in a severely discharged state and must
be charged before operation. Failure to do so may cause damage to the battery pack. When 3.0V
per cell is reached, the Sabertooth will shut down, preventing damage to the battery pack. This is
necessary because a lithium battery pack discharged below 3.0V per cell will lose capacity and
batteries discharged below 2.0V per cell may not ever recharge. Lithium cutoff mode may also
be useful to increase the number of battery cycles you can get when running from a lead acid
battery in non-critical applications. Because the system will continue to draw some power, even
with the motor shut down, it is important to unplug the battery from the Sabertooth promptly
once the cutoff is reached when using lithium batteries. If the Sabertooth is being run from NiCd,
NiMH or alkaline batteries, or from a power supply, switch 3 should be in the up position.
Lithium Cutoff enabled