Hella 2843 Series Keyed Battery Master Switch – Seawater-Proof, UL Listed
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Keyed Battery Isolation with Seawater-Proof Protection
The Hella 2843 Series Battery Master Switch gives you complete battery isolation with the added security of a keyed lockout — turn the red knob to Off, pull the key, and the battery circuit is interrupted and the switch can’t be operated without the key. It’s an effective deterrent against unauthorized use and a clean solution for vessels where battery security matters as much as battery isolation.
Rated at 1000A at 12V and 500A at 24V (10-second intermittent), this switch handles engine cranking loads on both 12V and 24V systems. The seawater-proof housing and tin-plated contacts are built for the harshest marine environments, and UL listing confirms it meets recognized safety standards. The M10 screw terminals accept heavy-gauge cable for direct main battery cable connection, and the switch works on either the positive or negative cable depending on your installation preference.
Key Features
- Keyed On/Off operation — key removable in Off position only
- 1000A at 12V / 500A at 24V (10-second intermittent rating)
- Seawater-proof housing
- Tin-plated contacts for corrosion resistance
- UL Listed
- M10 screw terminals — 2 terminals for direct main cable connection
- Works on positive or negative cable
- Black base with red knob for clear visual identification
Compatible Applications
- Main battery isolation on powerboats, sailboats, and pontoons
- 12V and 24V DC marine electrical systems
- Vessels requiring keyed battery security against unauthorized use
- Marina slip and trailered vessel theft deterrence
- Engine cranking circuit isolation
- Positive or negative main cable installations
Parts Desk Insights
Best use case: The Hella 2843 is the right switch when you want both battery isolation and key-based security in a seawater-proof package — particularly well-suited for sailboats and offshore powerboats where the switch may be exposed to spray or submersion, and for marina slip installations where unauthorized engine starts are a real concern. The M10 terminals handle heavy main cable gauges directly, and the positive-or-negative cable flexibility makes it adaptable to most existing wiring configurations without rewiring.
Related battery switches: For a removable-knob disconnect without key security, the Attwood Heavy-Duty On/Off Battery Switch is a compact alternative. For a lever-style disconnect with a brass case, see the Cole Hersee M284BP Battery Disconnect Switch. For full dual-battery bank selection, the Cole Hersee M750BP 4-Position Dual Battery Selector Switch adds 1/Both/2/Off capability.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.