CTEK Battery Charger - MUS 4.3 Polar - 12V

CTEK MUS 4.3 POLAR 12V Battery Charger – 4.3A – 56-958

The CTEK MUS 4.3 POLAR (Part No. 56-958) is a fully automatic 12V battery charger specially designed for reliable performance in extreme cold conditions. With specialized AC and DC cables engineered for low-temperature use, the MUS 4.3 POLAR can operate in temperatures down to -22°F (-30°C).

Featuring CTEK's advanced 8-step charging technology, the MUS 4.3 POLAR automatically tests, recovers, charges, and maintains your battery. It is suitable for a wide range of 12V lead-acid batteries and includes selectable 0.8A and 4.3A charging programs.

The patented RECOND mode helps recover deeply discharged and stratified batteries, while SNOWFLAKE mode provides optimized charging performance in extremely cold conditions. FLOAT/PULSE maintenance allows the charger to remain connected for long-term battery maintenance.

Simply connect the charger, select the desired program, and let the MUS 4.3 POLAR handle the charging process automatically.

Key Features

• Designed for extreme cold – Engineered for reliable charging down to -22°F (-30°C)
• 8-step automatic charging – Tests, recovers, charges, and maintains the battery
• 0.8A and 4.3A charging programs – Select the charging level based on your application
• RECOND mode – Helps recover deeply discharged and stratified batteries
• SNOWFLAKE mode – Optimizes charging performance in extremely cold conditions
• FLOAT/PULSE maintenance – Provides long-term battery maintenance during periods of inactivity
• Wide battery compatibility – Suitable for 12V lead-acid batteries including Wet, AGM, MF, and GEL
• Battery diagnosis – Determines whether the battery can receive and retain a charge
• Connect and Forget – Fully automatic operation after selecting the appropriate program
• Vehicle-safe operation – No need to disconnect the battery from the vehicle while charging
• Safety protection – Spark-free operation, reverse polarity protection, and short-circuit protection
• Clean power delivery – Designed to protect sensitive vehicle electronics from voltage surges and spikes
• IP65 rated – Splash-proof and dust-proof construction
• Long-term maintenance capability – Suitable for battery maintenance applications up to 160Ah

Specifications

Brand: CTEK
Model: MUS 4.3 POLAR
Part Number: 56-958
Voltage: 12V
Maximum Charging Current: 4.3A
Charging Programs: 0.8A / 4.3A
Charging System: Fully Automatic 8-Step
Battery Type: Lead-Acid
Compatible Batteries: Wet / AGM / MF / GEL
Charging Capacity: 1.2Ah–110Ah
Maintenance Capacity: Up to 160Ah
Operating Temperature: Down to -22°F (-30°C)
Ingress Protection: IP65
Warranty: 5 Years

What's Included

• CTEK MUS 4.3 POLAR 12V Battery Charger
• Low-temperature adapted AC and DC cables
• Charging connections

The CTEK MUS 4.3 POLAR 56-958 combines automatic battery recovery, charging, and maintenance with specialized cold-weather performance, making it an ideal choice for vehicles and equipment operating or stored in severe winter conditions.

This part also goes by the following cross reference.

Cross Reference Part Number: