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MEXICOWANDERER's avatar
MEXICOWANDERER
Explorer
Mar 18, 2013

12.5 Volt Battery To 11 Volt LED Fixture

Brand new 28 watt fixture given to me free. Originally 120 VAC. Stripped the regulator out for pure DC operation, emergency lighting off a smaller car jar battery. I am going to power it off the battery but in order to get "further into" this fixture means busting spot welds.

How well do current crop LED's stand up to varying voltage. I do not dare using 12.8 fully charged battery voltage, correct? But if I double gang diode the input, it will drop voltage, say 1.2 volts. In your experience will this put me in the ballpark for expecting decent lifespan?

The fixture also has a rating for wet locations which is sort of nice. BUT. The lens is frosted and from what I understand any faceting or diffusing just kills LED light output. Committing to removing the lens is well, permanent. Would it be worth it?

Some things I have adequate experience with, but when stuff unfamiliar to me comes into play I still have enough sense to ask questions and review the answers before getting out the hammer and chisel.

Thank you for suggestions and input. But remember, WHERE I am at before commenting. I cannot just shinny up a coconut palm and have my choice in LED fixtures.

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  • westend's avatar
    westend
    Explorer
    Mar 18, 2013
    They can tolerate about a 25% swing in overvoltage for short-term. Any long term use would invite the addition of a resistor or regulator. Ther diode should get you in the ballpark. The cheap Asian SMD panels in my rig are powered at 13.6 and seem to hold up well. I would see if the diffuser works out before putting it under the knife. Some LED's beam terribly. Have any regulator palms down there?
  • eb145's avatar
    eb145
    Explorer II
    Mar 18, 2013
    I guess it really depends on the specs of your LED bulbs / modules. It sounds like you already have the LEDs that are rated for 11V. I'm not sure what to say about your LEDs.

    Some LED bulbs include voltage regulation built into them. They are probably more expensive than unregulated.

    In my case, I replaced all of the incandescent bulbs in my trailer with LED replacement bulbs designed for automobile use. They are all working fine for about 1 year so far. Ebay for $1 or $2 per bulb from China takes 2 weeks to arrive. I ordered the lowest cost LED lights that had the right connections and lumens I was looking for.

    When my converter is in boost mode (14.4V) the LED lights I have definitely run hotter and brighter than at 12.6V or 13.2V. Not nearly as hot as the incandescent bulbs they replaced. Anyway, it's obvious the ones I have are not regulated. But since they are designed to work in cars that have between 12 and 14.5 Volts, they seem to work OK.

    Ed

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