Marine Lithium Battery Protection Kit | 12V/24V | Class T Fuse & Isolation Switch

Main battery protection for lithium systems on boats: a Class T fuse and a battery isolation switch, matched so they work together.

What's in the kit

• 1 x Heavy Duty On-Off 600A battery isolation switch (up to 32V)
• 1 x Class T fuse block (225–400A)
• 1 x Class T fuse (225A to 400A, choose above)

Which fuse size?

• 225A: one Energy Eco EE12-240 (200A BMS) or EE12-135 (150A BMS)
• 250A: larger 12V/24V banks, where the cable is rated for it
• 300A: Victron MultiPlus-II 24/3000 (Victron specifies a 300A DC fuse)
• 400A: Victron MultiPlus-II 12/3000 or 24/5000 (Victron specifies a 400A DC fuse)

The 600A switch is rated well above every fuse size in the kit, so the fuse always protects the switch. The fuse must also suit the cable size used. Suits 12V and 24V systems only.

Why Class T?

Lithium batteries can deliver very high short-circuit current. Class T fuses are built to safely break currents far above what standard MEGA or ANL fuses are rated for.

Installation (AS/NZS 3004.2)

• Fit the fuse on the battery positive within 200mm of the battery terminal (up to 1.8m if the cable is in extra protective covering).
• Mount the isolation switch close to the battery, readily accessible, and outside the battery compartment. No switches or fuses inside the battery compartment.
• Each main battery bank needs its own isolation switch, so order one kit per bank.
• Lithium systems also need a BMS alarm at the helm (not included).
• Not for installation in petrol engine spaces.

Main battery protection only. Solar and charging circuits need their own protection. Must be installed by a qualified installer.