Blue Sea 300A Red Mini m-Series On/Off Battery Switch w/ Lockable Key
Blue Sea 300A Red Mini m-Series On/Off Battery Switch w/ Lockable Key
300A Continuous Rating - Lockable Key Security - 48V DC Max

DESCRIPTION
Secure High-Current Switching for Marine and Vehicle Systems
The Blue Sea m-Series Battery Switch sets the standard for compact, high-performance power isolation. Designed for marine, caravan, and RV applications, this switch manages a single battery bank, allowing users to safely disconnect power during maintenance or storage. With a continuous rating of 300 Amps, it is perfectly sized for outboards, small petrol engines, and diesel engines, providing robust power handling without the bulk of industrial-grade switches.
Integrating a battery switch is essential for preserving battery life. By turning the switch to the 'Off' position, you eliminate parasitic loads that slowly drain batteries over time. This ensures that when you return to your boat or vehicle, your power system is ready to go. Its compact form factor allows for installation in tight spaces where traditional heavy-duty switches cannot fit.
Lockable Security for Safety and Theft Prevention
A standout feature of this specific model is the lockable key mechanism. Unlike standard rotary switches, this unit includes a removable key that secures the switch in the 'Off' position. This functionality provides two critical benefits: enhanced security and maintenance safety.
For vessel or vehicle owners, the key acts as a theft deterrent, preventing unauthorised use of the engine or electrical system. For technicians and DIY enthusiasts, it serves as a safety lockout, ensuring the circuit cannot be accidentally energised while working on the electrical system. This reduces the risk of short circuits and electrical shock during repairs.
Engineered for Harsh Environments
Reliability in marine environments requires superior materials. The m-Series uses tin-plated copper studs to offer maximum conductivity while resisting corrosion caused by salt mist and humidity. The studs feature a one-piece design, which is a significant improvement over standard two-piece bolts. This design ensures the stud never loosens from the switch body over time, maintaining a solid electrical connection and reducing the risk of overheating—a common point of failure in generic switches.
The unit is housed in a reinforced casing with an isolating cover that protects the rear contacts from accidental shorting. Breakout tabs on the cover allow for wire access in any direction, simplifying the wiring process in complex setups.
Versatile Connection Options
The switch is designed to accommodate modern heavy-duty cabling. The 3/8" (Approx. M10) stud terminals are robust enough to accept heavy-duty lugs, ensuring secure, low-resistance connections. With a stud length of 7/8" (22 mm), the terminals can accept multiple cable lugs, allowing for easy integration of additional loads or charging sources directly at the switch.
- 300 Amps continuous rating handles substantial 12V, 24V, and 48V loads comfortably.
- Lockable key design prevents accidental activation and enhances security.
- Tin-plated copper studs ensure maximum corrosion resistance and electrical flow.
- One-piece terminal studs prevent loosening, reducing fire risks and connection failures.
- Flexible mounting with breakout tabs supports various cable entry angles.
- Ignition protected marking makes it safe for installation aboard petrol-powered boats.
Improve System Safety Today
Upgrade your battery management system with the Blue Sea m-Series Lockable Switch. Whether you need to secure a vehicle against theft or ensure safe isolation for maintenance, this switch delivers professional-grade performance in a compact package.
SKU: BS-6004B
SPECIFICATIONS
Specifications
| Switch Type | Single Circuit ON-OFF |
|---|---|
| Color | Red |
| Maximum Voltage | 48V DC |
| Stud Size |
3/8" (approx. 9.53 mm; reference only) |
| Continuous Rating | 300A |
| Intermittent Rating | 500A |
| Starting Rating (30 sec) | 900A |
| Stud Material | Tinned Copper |
| Stud Torque |
120 in-lb (13.56 N·m) (approx. 10.0 ft-lb; reference only) |
| Switching Rating | 25A |
| Weight (min / max) |
0.65–0.65 lb (0.29–0.29 kg) (approx. 290 g; reference only) |
| SKU: | BS-6004B |
| Model #: | BS-6004B |
| MPN: | BS-6004B |
WARRANTY
Blue Sea Warranty Policy
Blue Sea Systems products sold by us are supplied with a warranty against defects for the warranty period shown below, subject to the product type, application and the terms of this warranty policy.
The express warranty provided by us is limited to a maximum of 5 years from the original date of purchase, unless otherwise required under Australian Consumer Law.
Blue Sea Systems may offer longer manufacturer support on some products at their discretion
Warranty Lengths by Product Range
| Blue Sea Product Range | Warranty Length | Application / Notes |
|---|---|---|
| Most Blue Sea Systems Products | 5 years | Applies to most Blue Sea Systems products found to be defective in materials or manufacture. |
| P12 Battery Chargers | 5 years | Warranty period starts from the original date of purchase. |
| P12 Remote Displays | 5 years | Warranty period starts from the original date of purchase. |
| Digital Meters | 3 years | Warranty period starts from the original date of purchase. |
| Vessel System Monitors | 3 years | Warranty period starts from the original date of purchase. |
Warranty Assessment and Remedy
If a Blue Sea Systems product is found to be defective in materials or manufacture within the applicable warranty period, we will, at our discretion, arrange a repair, replacement, store credit or refund, depending on the nature of the fault and the requirements of Australian Consumer Law.
Products may need to be returned for assessment before a warranty claim can be approved. Where required, the product must be returned with dated proof of purchase and a clear description of the fault.
Labour costs for removing, replacing, reinstalling or diagnosing a product are not covered by this express warranty unless otherwise required under Australian Consumer Law.
Making a Warranty Claim
To make a warranty claim, please contact us with your dated proof of purchase, product details and a description of the fault.
The product may need to be returned for inspection before the claim can be assessed. If the product is confirmed to be faulty and covered by this warranty, we will advise the available remedy.
What This Warranty Does Not Cover
This warranty does not cover faults or damage caused by incorrect installation, incorrect application, misuse, abuse, neglect, unauthorised modification, accidental damage, normal wear and tear, environmental damage, or failure to use the product in accordance with the manufacturer's instructions.
- Incorrect installation or wiring
- Incorrect product selection or application
- Misuse, abuse or neglect
- Physical or accidental damage
- Water ingress or environmental damage outside the product's intended use
- Unauthorised modification or repair
- Normal wear and tear
- Labour costs for removal, replacement, reinstallation or diagnosis
- Freight, travel or call-out costs unless otherwise required by law
- Products not returned for assessment when reasonably required
Manufacturer Support
Blue Sea Systems may provide additional manufacturer support on some products beyond the warranty period listed above. Where available, we may assist customers in contacting the manufacturer, but any manufacturer support beyond the express warranty period is subject to the manufacturer's own terms and continued availability.
Australian Consumer Law
This warranty is in addition to other rights and remedies available at law. Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.














































