DC/DC

The D250SE uses award-winning Swedish technology to charge, condition and maintain any type of 12 volt lead-acid or lithium service battery from 40-300Ah. It’s designed to work with smart alternators and will still operate if the alternator is shut off, but the vehicle has access to solar or wind power. It can charge from a solar panel and the alternator in parallel using its built-in regulator to save fuel.

Continuous charging while the vehicle’s on the move means the batteries are fully charged in the shortest possible time. The built-in temperature sensor compensates for hot or cold conditions to prevent the battery from overheating or overcharging, so it always gets the optimum charge.  

The SMARTPASS 120S delivers a 140A charge that prioritizes power from the alternator to charge the service battery. The SMARTPASS 120S automatically separates between the starter and service batteries and distributes power between them without the need for traditional diodes or voltage-sensitive relays.  

SMARTPASS 120S has a Battery Guard function to protect the service battery and ensure critical functions like emergency lights and communications systems always have the power they need and take priority over non-critical consumers. Battery Guard protects the service battery from total discharge and built-in over-temperature protection reduces charge current before the battery temperature gets too high.

SMARTPASS 120S has Start Assistance, which means the engine can be started using power from the service battery if the starter battery is flat.  

Together, CTEK’s D250SE and SMARTPASS 120S onboard charging system is a smart, powerful, flexible battery management system that gives commercial and recreational vehicle owners peace of mind and the power they need when they’re off road or off grid. 

Description of the Innovation - D250SE/SMARTPASS 120S

One of the key innovations of CTEK’s D250SE and SMARTPASS 120S onboard charging system is that it can be used with smart ECU controlled alternators which won’t always charge service batteries if the output voltage drops below a certain level. 

The system combats this by identifying if the ignition is on and allowing a lower input voltage when the engine is running. This means that vehicles can still take advantage of the benefits of smart alternators to reduce emissions and lower fuel consumption while still powering extra equipment from the service battery.

Unique to this system is the capability to charge from an external solar panel running in parallel with the alternator to save fuel – the built-in solar panel regulator with MPPT optimizes solar cell voltage and current for maximum charge in the shortest time. It also means that onboard electrical equipment can be powered just by solar, which reduces strain on the service battery. 

The D250SE/SMARTPASS 120S system has been designed to work with all 12V lead-acid batteries, including AGM, as well as lithium (12V LiFePO 4) to keep them at maximum capacity and extend their life. 

The D250SE has as selectable lithium and AGM mode and supplies up to 20A of power to any 12V lead-acid or lithium service battery from 40-300Ah.

The Battery Guard function makes sure that the service battery is always topped up to give critical functions all the power they need. The system automatically prioritizes critical over non-critical functions, while also protecting the service battery from damage caused by battery drain which can be a crucial feature for commercial vehicle applications.

If the starter battery is flat, the system’s unique Start Assistance function automatically connects the service battery to it to start the engine and displays a fault indication until the function is no longer needed.

Short Description - D250SE/Smartpass 120S

CTEK’s D250SE/SMARTPASS 120S onboard charging system is a smart, powerful and flexible battery management system that gives commercial and recreational vehicle owners peace of mind and the power they need when they’re off road or off grid.