CTEK D250SE DC-DC Battery Charger

Anyone who wants to keep a starter and service battery separate quickly runs into the limits of a regular battery charger. The CTEK D250SE is a powerful DC-DC charger built specifically for vehicles and boats with a starter battery and a separate service battery, keeping both topped up automatically. The unit accepts power from your alternator, a solar panel, or even both at once, letting you charge without mains power while driving or on the move. Once the service battery is full, the D250SE automatically routes surplus power to the starter battery, so you never end up with a flat one. With a stable output up to 20A, support for smart Euro 6 alternators, and compatibility with both lead-acid and lithium batteries up to 300Ah, this is the charger for anyone who drives or sails seriously off-grid.

What's inside

1x CTEK D250SE DC-DC battery charger with temperature sensor, connection cables and installation manual.

Why this product

• Dual-battery charging: automatically keeps starter and service battery topped up

• Combines alternator and solar panel: dual power input at the same time

• Stable 20A output: even with smart Euro 6 alternators and varying voltage

• Lead-acid and lithium: suitable for AGM, gel, EFB and LiFePO4 batteries

• Works without mains power: ideal for campers, boats or overlanders

• IP65 housing: resistant to weather and moisture on the road

How to use

1. Connect the D250SE between alternator or solar panel and the service battery (Follow the installation manual for correct cable thickness and fusing)

2. Connect the temperature sensor to the service battery (This optimizes charging voltage based on the current temperature)

3. Start the engine or position the solar panel in the sun (The D250SE automatically starts the 5-step charging program)

4. Let the system continue working on its own (Once the service battery is full the charger switches to maintaining the starter battery)

For a tidy installation, route your wiring neatly with the Mavel 15m Cable Reel.