CTEK M25 12V 25A Marine Battery Charger (40-201)

The CTEK M25 is a professional-grade 12V battery charger engineered for marine and workshop environments where reliable, high-current charging is critical. Unlike compact trickle chargers, the M25 delivers a full 25A charging current, enabling rapid recovery of large battery banks up to 500Ah while protecting sensitive electronics with its spark-free, reverse-polarity-safe design. Its fully automatic 8-step charging algorithm, including reconditioning and temperature compensation, ensures optimal battery health and longevity, making it the go-to choice for boat owners, service technicians, and anyone managing multiple lead-acid batteries.

Highlights

• High 25A charging current for fast charging of large batteries
• 8-step fully automatic charging with reconditioning mode
• Temperature compensation for safe charging in all climates
• IP44 splash-proof housing for marine use
• Spark-free and reverse polarity protected
• Supply mode provides stable 12V/25A power for equipment

In daily use

The M25 simplifies battery maintenance with its clear LED indicators and robust construction. Connect the included clamps or eyelets, select the appropriate mode, and the charger handles the rest—from desulphation to float maintenance. The 2m DC cable and 1.5m AC cable provide flexibility in tight engine compartments, while the IP44 rating ensures durability against splashes and dust. Whether charging a single deep-cycle battery or maintaining a bank, the M25's adaptive charging protects against overcharging and extends battery life.

Full specifications

• Output voltage: 12V
• Max charging current: 25A
• Supported battery types: 12V lead-acid (WET, MF, Ca/Ca, AGM, GEL)
• Recommended battery capacity (charging): 40-500 Ah
• Recommended battery capacity (maintenance): 40-500 Ah
• Charging stages: 8-step fully automatic
• Input voltage: 220-240V AC, 50-60Hz
• IP rating: IP44
• Recondition mode: Yes
• Supply mode: Yes (12V, 25A)
• Temperature compensation: Yes
• Safety features: Spark-free, reverse polarity protected, short circuit proof
• Ripple: <4%
• Operating temperature: -20°C to +50°C
• Efficiency: >85%
• AC cable length: 1.5m
• DC cable length: 2m

Final note

Built to withstand harsh marine conditions and deliver dependable charging year after year, the CTEK M25 is an investment in battery performance and peace of mind.