1485 Jacobs Rd.
Deland, FL 32724
386.738.7307
P/N 53-00606-100 Rev. D 032619
www.intellitec.com
Intellitec
SERVICE MANUAL
BATTERY CONTROL CENTER - MINI DIESEL
How The Battery Control Center Works
Battery Disconnect -
Charging Circuit -
Auxiliary Start -
Ignition Switched Power -
Fog Light Relay -
Circuit Breakers -
The Battery Disconnect relays are used to disconnect the batteries during periods of storage, or during service.
The disconnect relays operate by momentarily applying 12 volts to the solenoid coil in either of two directions,
(+12 volts on the "S" terminal and ground on the "I" terminal for opening) and (+12 volts on the "I" terminal and
ground on the "S" terminal for engaging). The actuation voltage is supplied from the highest voltage of either
the Auxiliary or Main battery through F19. The voltage is supplied to the momentary switches mounted in the
coach and then fed back to the relays in the box. (See Battery Disconnect schematic, Figure 2).
The charging circuit, (which utilizes an isolator solenoid to connect the two batteries together for charging) will
charge both batteries if either battery is being charged. It operates by sensing the voltage on the Main and
Auxiliary batteries. If either voltage goes above 13.3 volts (the minimum necessary to fully charge a battery)
for more than 14 seconds, the isolator solenoid will pull in, charging both batteries. If, while the ignition is on,
the voltage falls below 12 volts for more than 4 seconds, the isolator relay will open, keeping all of the
alternator's output available for the chassis functions. If the ignition is off and the Auxiliary battery voltage
should drop below 12.8 volts (voltage of a fully charged battery) for 4 seconds, the isolator relay will open,
preventing the coach loads from discharging the main battery. (See Charging Circuit/Aux Start schematic,
Figure 3).
The Auxiliary Start function is used to provide a "jump start" from the auxiliary battery in the event that the Main
battery does not have sufficient charge to start the engine. It operates by momentarily connecting the Main and
the Auxiliary batteries together through the isolator relay. This function is accomplished by pressing the dash
mounted switch, which applies 12 volts to the isolator relay coil. The switch power is supplied by fuse F17.
(See Charging Circuit/Aux Start schematic, Figure 3).
The ignition circuits are switched by three relays, K1, K2, and K4, to supply power to the horn, rear heater,
power windows and the power seat. The power for these relay coils comes from the ignition switch through J4,
pin 11. (See Charging Circuit/Aux Start schematic, Figure 3).
The Fog Light relay supplies 12 volts to the fog lights, when the coach is so equipped. To operate the fog lights,
12 volts from the ignition is fed to a dash mounted fog light switch and is applied to the relay's coil, through pin 12
of J4. The fog light's power comes from the Main battery through fuse F13. It is switched by the relay and is
routed from the printed circuit board through plug J4, pin 9. (See Fog Light schematic, Figure 4).
Each of the ignition relays is rated at 30 Amps,
therefore the sum of the total continuous currents through relay K2, which includes fuse F6 (J5, pin 4)+F8 (J5,
pin 6), must not exceed 30 Amps. In like manner, the sum of the total continuous currents through relay K1
which includes fuse F9 (J5, pin 7)+F10 (J5, pin 8)+F11 (J11) must not exceed 30 Amps, and the sum of the total
continuous currents through relay K4 which includes fuse F12 (J12)+F22 (J17)+F23 (J18) must not exceed 30
Amps.
There are two 30 Amp circuit breakers, located near the front at the bottom of the box, that are used to protect
the wiring between the Auxiliary battery and the converter. These breakers have manual reset buttons that pop
out when they are tripped ( See Figure 5)
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