Ampper Top-Post Battery Disconnect Switch - Negative 12–48V On/Off, Space-Saving 275A Continuous

This top-post battery disconnect from Ampper replaces the negative terminal on standard lead-acid batteries to provide a simple on/off cutoff for cars, RVs, boats and other 12–48V systems. Engineered to fit directly on the negative top post (17 mm cone/tapering), the switch keeps installation tidy and requires no extra lugs or long cables. Rugged ABS housing and heavy-current ratings let it handle routine starting loads and intermittent surges while freeing you from parasitic drains when a vehicle or vessel is stored.

How does this switch save space and simplify installation?

The Ampper top-post design mounts directly to the battery negative post so there is no need to route new battery cables or modify the battery tray. Its compact footprint is built for tight engine bays and crowded battery compartments, giving installers more routing options and cleaner results.

• Direct-fit top post negative terminal (17 mm) — no extra lugs required
• Space-saving ABS housing suited for cramped installations
• Can be used alone or locked together with another switch for multi-battery setups

What electrical loads and voltages can it handle safely?

Designed for DC systems from 12 to 48 volts, the switch supports everyday starting currents and higher surge conditions. Its ratings make it appropriate for automotive and marine applications where intermittent heavy loads occur.

• 275 A continuous rating at 12V for steady currents
• 455 A intermittent capacity at 12V for short-term higher demand
• 1250 A momentary rating at 12V to withstand crank or surge events

Will this work with my battery and is it durable enough for marine use?

The Ampper switch is compatible with standard top-post batteries—positive posts at 19 mm and negative at 17 mm taper—and is housed in robust ABS plastic to resist typical shop and marine environments. While not a sealed marine-grade remote switch, its construction is intended for safe use in vehicles, RVs, and boats when installed in reasonable protected locations.

• Fits common top-post battery sizes: 19 mm positive, 17 mm negative
• ABS plastic housing offers impact resistance and long-term durability
• Removes parasitic draw to protect battery during storage or transport

How do I use it day-to-day and what comes in the kit?

Operation is straightforward: turn the switch on to reconnect the negative terminal and off to isolate the battery. The product ships as a complete kit so you can install immediately without needing additional connectors or extension cables.

• Simple two-position On/Off operation for quick isolation
• Complete kit includes the switch and all necessary accessories for top-post installation
• Can be combined or locked with other switches for multi-battery control

Who this is for: Ampper’s top post battery disconnect is aimed at owners and technicians who want a compact, no-fuss method to isolate a vehicle or marine battery. It’s ideal for car and RV owners who store vehicles seasonally, boaters seeking to prevent parasitic drains between trips, and workshop professionals needing a neat, direct-fit negative switch for routine maintenance and safety checks.