CTEK MUS 4.3 Lithium & Lead-Acid Smart Battery Charger / Tender

The CTEK MUS 4.3 TEST & CHARGE is an advanced microprocessor-controlled battery charger, maintainer, and diagnostic tool designed for both lead-acid and LiFePO₄ lithium batteries. It automatically tests, charges, conditions, and maintains the battery, making it ideal for Corvettes and other performance vehicles that may sit for extended periods.
Key Features

Compatible with lead-acid and LiFePO₄ lithium batteries

Supports WET, MF, Ca/Ca, AGM, EFB, GEL, and LiFePO₄
Battery capacity range from 1.2Ah to 110Ah

Intelligent 8-step charging process

Tests battery voltage, starting power, and alternator health

RECOND Mode for deeply discharged and stratified batteries
FLOAT/PULSE modes for long-term battery maintenance
Spark-free operation
Reverse-polarity protection
Clean charging voltage with no surges or spikes
Charge without disconnecting the battery from the vehicle
0.8A and 4.3A charging modes
Cold-weather “Snowflake” charging mode

Lithium & Lead-Acid Compatibility
Unlike battery maintainers designed around only one battery chemistry, the MUS 4.3 supports a wide range of traditional lead-acid batteries as well as LiFePO₄ lithium-ion batteries.
This makes it especially useful for Corvette owners as battery technology changes between model years. The source specifically notes that 2027 C8 Corvettes are equipped with lithium batteries and states that GM training documentation recommends a charger when the vehicle sits for more than a week.
Intelligent Charging & Maintenance
The charger's 8-step charging system automatically evaluates battery condition before charging and maintaining it. For vehicles stored for extended periods, FLOAT/PULSE maintenance helps keep the battery properly maintained without requiring constant attention.
A dedicated RECOND mode is also available for recovering deeply discharged or stratified compatible batteries.
Built-In Battery Diagnostics
In addition to charging and maintaining the battery, the MUS 4.3 includes three testing programs that can evaluate:

Battery voltage
Starting power
Alternator charging health

This gives the charger additional diagnostic functionality beyond a traditional battery tender.
Safe Connect-and-Forget Operation
The charger delivers clean power without voltage spikes or surges and incorporates spark-free operation and reverse-polarity protection. The battery can remain connected to the vehicle during charging, helping make routine battery maintenance simple and convenient.
Vehicle Compatibility
Suitable for compatible 12V lead-acid and LiFePO₄ battery applications, including listed Corvette and Cadillac applications such as:

C7 Corvette
C8 Stingray
C8 Z06
C8 E-Ray
C8 ZR1
C8 ZR1X
C8 Grand Sport / Grand Sport X
Cadillac CT5 Blackwing

Always select the charging program appropriate for the battery chemistry installed in the vehicle.
Warranty
Covered by the manufacturer's warranty, if applicable, for the original purchaser. Warranty is non-transferable and subject to applicable terms.