ASC+ System Auto Split Charge & Engine Start Protect
User Guide and Installation Instructions
Document No 13362 Issue 04
Page 13 of 21
ASC (Auto Split Charge) operation
Using Battery Link (Emergency / Assured Start) function
If the main battery is depleted the auxiliary battery can be linked to the main battery to assist
starting, to use this feature depress the “Battery Link” switch. The secondary ASC contactor
will be pulsed closed to link the batteries and the “Battery Link” switch LED will flash to
indicated “Battery Linked” mode.
If a charging voltage is seen (i.e. the vehicle starts) then the ASC contactor will remain closed
(see ASC standard operation) and the “Battery Link” switch LED will stay on.
If after 60 seconds a charging voltage is not seen (i.e. the vehicle doesn’t start) then the
secondary ASC contactor will be pulsed open to stop both batteries being depleted.
Note:
The battery link switch can only be operated up to 3 times in a 5 minute period.
See the flow chart Figure 3 on page 15 for the flash patterns during this mode
ASC standard operation
The ASC contactor “Battery Positive” terminal is monitored. When a charging voltage is
detected the secondary ASC contactor will be pulsed closed to link the “Battery Positive”
terminal and the “Load Positive” terminal. The “Battery Link” switch LED will illuminate to
indicate that the batteries are linked.
The ASC contactor remains closed until the battery voltage falls to a level which indicates
that the MAIN battery is being discharged. At this point, the ASC contactor will be pulsed
open. See Table 2 for open & close voltages
Note: When a charging voltage is detected and the ASC closes, it will remain closed for a
minimum of 30 seconds regardless of the voltage.
See the flow chart Figure 4 on page 16 for the flash patterns during this mode
ASC dual sense operation
This function is identical to ASC standard operation, except that the “Load Positive” terminal
is also monitored and acted upon. This allows the MAIN battery to be charged if the auxiliary
is being charged. The “Battery Link” switch LED will illuminate to indicate that the batteries
are linked. See Table 2 for open & close voltages.
System Voltage Closing Voltage Opening Voltage
12V 13.18V 12.70V
24V 26.36V 25.40V
Table 2
ASC battery protect
In any of the above operations both studs are monitored. If a voltage of 3V or less is detected
on either stud, the ASC contactor will not close. This is to prevent a short circuit being placed
on the batteries. The “Battery Link” switch LED will flash to indicate a system fault. See flow
charts Figure 3 and Figure 4 for the flash patterns during this mode.
