Low Voltage Disconnect

Low Voltage Disconnect

SureStart Compact Low Voltage Disconnect Switch

48513    Compact LVD
48513-01    LVD & Harness
48513-03    LVD, Harness and Rocker Switch
12804    Harness

12 or 24V, 125A at 60ºC, 100A at 85ºC

Electronically senses battery voltage and conserves starting power. Automatically disconnects and reconnects loads based on battery condition; no operator action is required to protect the batteries. Prolongs battery life by preventing damage due to excessive discharge.

Eliminates the need for both separate timer or voltage sensing delay relay devices and high current relay or solenoid, and simplifies wiring and installation. Small size and lightweight design means easier and more discrete mounting, to use space more efficiently, eliminate hardware, and give better routing of wires.

When battery voltage falls below programmed voltage setting for 2 minutes non-critical loads are automatically disconnected. Waterproof and dustproof to IP67 international standard.

(Submersible to 3 feet.) Sealed connector makes it ideal for harsh environments. Advanced technology enables a robust product in a small lightweight package. Programmable timer feature automatically disconnects loads after key off, regardless of battery condition. 12804 Harness fits this LVD.


  • 4.5"W x 4.3"L x 3.1"H (114.3 x 108.6 x 79.0mm).
  • Operating Temperature Range: -40° to +85°C (-40° to +185°F). 100A at 85°C, 125A at 60°C.
  • Ingress Protection: IP66 per IEC 529.
  • Humidity: 0 to 90 %RH.
  • Vibration: 10-500 Hz per SAE J1455.
  • Shock and Thermal Shock: per SAE J1455.
  • Inductive Transient: +/- 600V per SAE J1455.
  • Load Dump: + 100V per SAE J1455.
  • Battery Terminal Torque: 50 in-lbs max.
  • Operating Voltage: 9V min, 12V typical, 16V max if used with 12V DC systems.
  • Disconnect Voltage: 12.05V min, 12.1V typical, 12.15V max
  • When voltage drops below 12.1V, system activates the alarm for one minute and then disconnects loads.
  • Quiescent Current: 1mA typical, 2mA max. Circuit operating current.
  • Load Current: 100A at 85°C, 125A at 60°C.
  • Overcurrent Protection: 150A. System will disconnect load and sound alarm after 5 seconds of excessive current.
  • Key-Off Ttimer: 5 minutes minimum, 15 minutes typical. Option feature. After key off, unit will wait a set time before activating alarm. One minute later loads are shut off.


SureStartTM Automatic Low Voltage Disconnect Switch

Ensures ample starting capacity and prolongs battery life. Automatically disconnects non-critical loads from a battery when the battery voltage falls below a predefined threshold. Automatically reconnects the loads to the battery when it is being charged. Manual override permits a user to make or break the connection, regardless of battery voltage. Overcurrent, short-circuit and over-temperature protection.

48510 200A at 12V DC

48512 150A at 12V DC


No more stranded vehicles! Avoid the time and expense of getting your vehicles towed. The SureStartTM LVD ensures there’s enough power to start, and saves the batteries on vehicles that aren’t used every day.



  • 6.0"L x 5.1"W x 3.0"H (152.4 x 130.2 x 76.2mm).
  • Environmental: -40˚C to 85˚C. SAE J1455 & J1113.
  • Electrical: 150A or 200A continuous. Inrush: 500A
  • (for 5 seconds). 2mA max quiescent current.
  • Ignition-proof to ISO 8846.
  • Disconnects when battery drops below 12.1V for 2 minutes, reconnects when battery meets or exceeds 13.0V for 10
  • seconds. (Factory programmable).
  • Alarm: Active low, 50mA.
  • Activates 1 minute before disconnect. (Factory programmable) Accuracy: ±100mV.
  • Electronics sealed to IP67.


LVD Accessories

58036-06 Rocker Switch
Mom On-Off-On SPST switch for use with LVDs. Uniform with series 58031 & 58332 switches on page 4. Use with 48513.
12804 Harness
Harness kit (Deutsch connector & wires) fits 48513
Compact LVD.
40205 Milliamp Rocker & Alarm
Digital switch with piezo alarm. Use with 48510 and 48512.

Battery Management