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Solid state battery isolators.


Fully sealed with no moving parts meaning you can always rely on Cartek kits to work in the tough environments of motorsport.


Solid state means no moving parts, all power switching is fully electronic.


Early types of electrical isolation were by large mechanical master-switches while more modern systems have utilised electro-mechanical solenoids.


Both of these types of systems contain mechanical electrical contacts which, due to the combination of high electrical current and the shocks and vibration of the race car environment, sparking between the contacts occurs which results in contact erosion and eventual unreliability.


These solid state battery Isolators are also filled with a hard setting resin which prevents any ingress of dust, dirt or water therefore further increasing their strength and reliability.


The Cartek Battery Isolators provide two functions. The first is to disconnect the Battery from all Electrical Circuits. The second is to kill the engine.


The Battery Isolators work by being fitted in between the negative side of the battery and the chassis ( As seen above ). When the external kill button has been activated or the internal button been switched to the off state, then the Battery Isolator will disconnect the negative side of the battery from the Chassis.


This means that no power can get to any of the electrical circuits as there is a break in the circuit.


To kill the Engine there are two options of Battery Isolator, the GT kit or the XR.


GT: This kills the engine by taking in a fixed 12v input and sending a 12v output that would power your Ignition or ECU. When the negative side of the battery has been disconnected it will also cut the 12v output powering your Ignition or ECU. This will kill the engine. Designed for cars with Standard ECU’s or Historic Race cars.


XR: This unit does not have a power input or power output. Instead it sends a signal which is wired up to either a Power Distribution Module or Motorsport ECU that has an ignition switch signal input. The ECU or Power Distribution Module will then shut down when it see’s this signal – which then kills the engine.The new Battery Isolator XR also features a 0.5 sec time delay between transmitting the engine kill signal and disconnecting the battery allowing ECUs time to perform a shutdown sequence before electrical power is lost.


As Cartek Battery Isolators use ‘push to break’ external kill buttons it then allows use of two external buttons to be fitted in series. This was implemented by Ford in the Formula Ford Ecoboost series. If any of the Formula Ford cars would end up against a barrier or upside down, it then allowed a marshall to always have access to kill the engine.


The unit will instantly trigger into isolation mode when any of the kill buttons are struck or on detection of any fault or break in switch wiring circuits.


Both the Battery Isolator GT and Battery Isolator XR come with built in alternator run down protection meaning no extra wiring and no extra components.


The two electronic isolation circuits are controlled by microprocessors and incorporate various safety systems including over-temperature and over-current monitoring. These microprocessors also monitor the kill switches/buttons for instant activation without false triggering.


Unlike race seats, harnesses and fire extinguishers the FIA does not have an approval procedure for Master Switches. However, most FIA race and rally championships require cars to be fitted with a spark-proof master switch to isolate the battery from all electrical systems and stop the engine. The Cartek Battery Isolator meets these requirements.


GT or XR?


Cartek produces two types of Battery Isolator GT and XR.

Both systems isolate the battery from all electrical circuits, in accordance with FIA requirements, by disconnecting the negative terminal of the battery from chassis/earth. However, the main difference between these two units is the method used to stop the engine. The GT unit has a 30A switched power output which can be used as the main power feed for most ECUs and/or ignition systems while the XR unit outputs a low current, ‘Ignition Off’, signal which is compatible with most motorsport ECUs and PDMs. This latter method of engine kill means that the XR is smaller and lighter than the GT and incorporates a sealed, circular connector.

Cartek Battery Isolator Master Switches

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