Hella Marine 5637 Replacement Light Bulb, 24V 10W, BA15s Base

Overview

The Hella Marine 178560241 is an incandescent replacement bulb rated 24V and 10W with a BA15s single-contact bayonet base, commonly used in navigation and interior light fixtures.

It is a straightforward swap when your fitting calls for a 24-volt BA15s bulb. It is also commonly referenced as a 5637 or R10W style bulb, which can help when matching an existing spare.

Because this is a filament bulb, it runs warm in use. Keep the lens and housing in good shape and stick with the specified wattage so the fixture does not overheat.

Key features

• 24V, 10W rating for 24-volt lighting circuits
• BA15s single-contact bayonet base
• Incandescent light source for fixtures that are set up for standard filament bulbs
• Common cross-reference: 5637 / R10W style bulb
• Useful for keeping existing navigation and interior fixtures running without changing the light

Compatibility and fit

Confirm the socket type in your fixture before ordering. BA15s is a 15 mm bayonet base with a single contact on the bottom. If your light takes BAY15d or a wedge base, this bulb will not seat correctly.

This bulb is for 24V systems only. On boats with both 12V and 24V circuits, check the supply at the light or on the fixture label to avoid an early failure.

Installation and setup

Switch off the circuit at the panel and let the bulb cool. Remove the lens or cover, press and twist the old bulb to release it, then push in and twist the new bulb until it locks.

Handling the glass with a clean cloth helps keep oils off the surface, which is especially helpful in enclosed navigation light housings where heat builds up.

Use cases on board

This bulb is a good match for skippers running 24V lighting on workboats, commercial vessels, and larger cruisers that still use incandescent navigation or cabin fixtures. Keeping a couple of spares on board can make a quick dockside fix instead of a late-night parts run.

Maintenance and care

After replacement, check the gasket and lens for cracks, then test the light with the cover secured. If the socket shows corrosion, clean the contacts and address any moisture entry so the new bulb is not exposed to the same problem.