User Manual

Lithium cutoff:
Switch 3 of the DIP switch block selects lithium cutoff. If
switch 3 is in the down position as shown the SyRen 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 SyRen 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 recharge –
ever.
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 SyRen promptly once the cutoff is reached when using lithium batteries. If the
SyRen is being run from NiCd, NiMH or alkaline batteries, or from a power supply, switch 3
should be in the up position.
User-adjustable current limit:
The blue potentiometer on the board sets the current limit.
The SyRen 50 can handle up to a 100A limit. There are
many circumstance where you may need 50A, but do not
want to let the system draw more than 60A or 70A. Some
motors may have a rated stall current of 60A. You can set
the SyRen 50’s adjustable current limit to 50A and never
put your motor in harm’s way with a dangerous stall.
This option can be used to limit acceleration and starts with
too much torque. It will basically act as an on-demand ramp that will only activate when you’ve
reached the set limit. In some situations, long wire runs will prevent higher amount of current to
be drawn due to heat. This option can reduce the amount of current being drawn and thusly
reduce heat through the wire.
If you have an application where a vehicle could run into a wall, or an automatic door could pin
someone or something, the adjustable current limit could be set to detect this and greatly reduce
output to the motors.
Lithium Cutoff enabled
Current limit potentiometer