Free shipping on orders over $100



With award-winning Swedish technology, the dual input D250SA (Part #40-186) can draw its power from smart alternators and other DC sources, making it the ideal charger for vehicles that don’t have access to a main power supply. Its dual input capability means it can draw power from solar and wind sources, in parallel to the alternator.

The D250SA is a fully automatic, 5-step charger that supplies up to 20A of power to charge, and conditions and maintains any 12V lead-acid service battery from 40-300Ah, including Wet, MF, Gel, AGM. EFB, and Ca/Ca. The D250SA uses patented technology so it’s safe for you and your vehicle’s electronics. It’s also IP65 classified (splash and dustproof) and comes with a 2-year warranty.


  • Continuous, fully automatic charging while you’re on the move for maximum performance, battery life, and convenience
  • Compatible with smart alternators
  • Protects, charges, and maintains your starter battery – even if the engine is not running – and charges service batteries from your starter battery without the risk of starting problems
  • Fast charging from the alternator and other DC sources – even on short journeys
  • Automatic energy management in a single, easy to use unit – no need for traditional diodes or VSR relays
  • Environmentally friendly charging with solar or wind


  • Input: 11.5–23V, 25A
  • Output: Max 14.4V (14.7V in AGM), 20A
  • Back current drain: Less than 1Ah/month
  • Ambient temperature: -20°C to +50°C (-4°F to +122°F)
  • Battery types: All types of 12V lead-acid batteries (WET, EFB, Ca/Ca, MF, AGM, and GEL)
  • Battery capacity: 40–300Ah
  • Dimensions: 192 x 110 x 65mm (L x W x H)
  • Insulation class: IP65 (splash and dust proof) 40-186

“Having owned several of another ‘popular’ brand of charger, the CTEK is far and above superior in every possible category. WELL worth the miniscule additional cost. ”