Blue Sea Systems 7615 Automatic Timer Battery Disconnect 120A 12V

The Blue Sea Systems ATD Automatic Timer Disconnect is an intelligent battery management device that automatically shuts off connected devices to preserve battery power. This versatile 120A relay can be configured to operate in four different modes: Timer Disconnect, Low Voltage Disconnect, Automatic Charging Relay, or simple Solenoid.

Timer Disconnect Mode:

• 12V signal triggers relay to connect battery power to devices
• Adjustable timer disconnects devices after preset time when signal is removed
• Timer range: 15 minutes to 4 hours
• Optional charge sense can replace 12V signal to simplify wiring
• Test mode confirms relay and timer operation with 5-second disconnect

Low Voltage Disconnect Mode:

• Automatically disconnects devices when battery voltage drops below threshold
• Adjustable voltage settings: 11.0V, 11.5V, or 12.0V
• Can be used with Timer Disconnect for dual protection
• Disconnects before timer expires if low voltage detected

Automatic Charging Relay Mode:

• Combines two batteries when charging from single source (alternator)
• Isolates batteries when charging source is inactive or discharging
• Single-side sensing monitors start battery voltage only
• Ideal for AGM auxiliary batteries or batteries larger than start battery

Solenoid Mode:

• 12V signal connects or disconnects relay with no time delay

Technical Specifications:

• Nominal voltage: 12V DC (input range 9.5-16V)
• Continuous rating: 120A
• Intermittent rating: 210A (5 minutes)
• Operating current: 175mA (combined), 4mA (open)
• Terminal stud size: 3/8"-16 (M10)
• Terminal torque: 140 in-lb (15.82 Nm)
• Cable size: 1 AWG recommended, maximum 1/0 AWG
• IP66 rated and ignition protected

Additional Features:

• Integrated LED status indicator
• Clip-on cover insulates terminal connections
• One-piece stainless steel flange nuts for secure connections
• Charge sense activation at 13.0V or greater (3 sec delay)
• Timing activation at 12.75V or lower (10 sec delay)
• Over-voltage protection disconnects at 16.0V or greater (5 sec delay)

This multi-function device provides flexible battery management solutions for marine, RV, and automotive applications where preserving battery power and preventing deep discharge is critical.