Conserve battery power with LEDs


By Gary Bain

Over time, I have made many changes and improvements to Gone With The Wind, a 1990 MK1 Catalina 36. This year I decided to convert all the interior lights to LED.

Several years ago a good friend gave me an LED light fixture to replace the one adjacent to the chart table. The original light had a warm glow, and I was hesitant to change it out. I decided to put the new fixture over the galley sink, but I didn’t care for the extreme blue/white light.

Now that the LED industry has developed a warmer light, I found a good source of marine LEDs at I purchased three fluorescent replacement LED bulbs to replace the fluorescent bulbs in two fixtures in the galley and one in the head. The LEDs give off a much warmer glow than standard fluorescents. The company supplies directions and has videos on its website showing how to prepare your old fixtures to accept the LED bulbs. Basically, you remove the existing ballast and jump the wires to complete the circuit , as shown above. Simple enough!

I replaced the bulbs in most of the other fixtures with simple Marinebeam bayonet-style bulbs—six in the forward and main cabins and another in the aft cabin. I also purchased an LED bulb for a dome-style fixture in the aft cabin. In total I converted 11 fixtures to LED. All emit a warm white light, similar to normal incandescent bulbs.

As I mentioned earlier, I did not replace the fixture over the chart table, and the amp draw on this fixture alone is 1.6 amps. With nothing turned on, my system shows a 0.1 amp draw, which is from the Xantrex link monitor. In the near future, I plan to offset that draw by adding a solar panel.

With all of the LED fixtures turned on, the meter shows only a 0.8 amp draw; subtracting 0.1 amps for the link monitor, that’s a total of 0.7 amp hours, as shown in the inset photo. Of course we don’t have all the lights on at once, but you can see how you can save amp hours by converting to LEDs. This is particularly important if you aren’t tied to a recharge source and need to run the motor.

My boat has a main battery bank with four 6-volt golf-cart batteries hooked up in a series to give it 440 amp hours. The link monitor is set to one-half that at 220 amp hours, so I have plenty of reserve power. The boat also has a 120-amp alternator and a regulator with a combiner to keep the batteries charged when running the iron jenny.

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