Perko Medium Duty Battery Selector Switch with Alternator Field Disconnect, No Key Lock, 6-32V, 250A Continuous, Ignition Protected

Overview

The Perko 8503DP is a medium duty battery selector switch with alternator field disconnect for 6 to 32 VDC marine electrical systems. It is rated for 250 amps continuous and 360 amps intermittent, and it uses 1, ALL, 2, and OFF positions to manage two-battery setups where manual battery selection is still the preferred approach.

This model is ignition protected, so it can be installed in engine spaces on gasoline-powered boats where that matters. The housing measures 5-1/4 inches in diameter and 2-5/8 inches deep, with a polycarbonate body, brass terminals, and a no-key-lock layout that keeps the switch easy to reach when you need to isolate power or change battery selection quickly.

Key features

• Selector switch with 1, ALL, 2, and OFF positions for manual control of two battery banks.
• Make-before-break action between 1, ALL, and 2 allows battery selection changes while the engine is running.
• Alternator field disconnect helps reduce the chance of alternator damage if the switch is turned to OFF while running on systems with non-unitized alternators.
• Ignition protected for use in gasoline engine compartments.
• Rated for 6 to 32 VDC systems at 250 amps continuous and 360 amps intermittent.
• Surface-mount body with a 5-1/4 inch diameter and 2-5/8 inch depth.
• Polycarbonate body with brass terminals and no key lock.

Compatibility and fit

This switch suits boats with separate start and house batteries, and it also works in twin-switch layouts on twin-engine installations. It is a selector switch rather than a simple on and off disconnect, so it fits systems where the operator needs to run from battery 1, battery 2, or both together.

For replacement work, it uses the traditional Perko bolt circle found on many existing installations, which can simplify swap-outs on older panels. The alternator field disconnect function applies to non-unitized alternators. On unitized alternators with a built-in regulator, that field disconnect circuit is not used.

Installation and setup

The switch is surface mounted, so rear clearance matters as much as face diameter. In tight battery lockers or behind helm panels, allow room not only for the 2-5/8 inch body depth but also for cable bend radius and access to the rear terminals.

It is best placed where battery cables can stay as short as practical and where the knob can be reached without digging into the compartment. In spaces that stay damp or see salt exposure, terminal connections should be protected against corrosion, and the wiring should be done to marine electrical standards by a qualified installer.

Use on board

This is a good match for owners who want direct control over battery selection on a coastal cruiser, center console, sailboat, or small sportfishing boat without moving to an automatic battery management setup. It also makes sense where quick access matters more than keyed security, such as a dedicated battery switch location inside a console, cabin locker, or machinery space.

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Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

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Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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