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School me on LEDs (worth it?)

Discussion in 'Gen 3 Prius Accessories and Modifications' started by qdllc, Apr 9, 2015.

  1. qdllc

    qdllc Senior Member

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    I have a 2013 Prius Two.

    I know some people switch over to LED bulbs. I know LEDs draw less power, which I don't see as a BIG issue on something less than a Prius Plug-In. Really, unless you are driving at night or rainy conditions, how much is it helping?

    Still, is there a benefit? Which are worth doing?
     
  2. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    For a house?
    Yes.
    Retrofitting is a no brainer.

    For a Car?
    I do not know.

    My 2010 has non LED, regular old lamps.
    They actually work surprisingly well for a small car, and I used to drive at night a LOT.

    Nothing looks more lame than some kid sticking blue "wanna-be" lamps into a hoopdi.
    OEMS are going to replace current lamps with LEDs as the technology improves, and there may be good replacements available for my G3, but I'm just not sure that the benefit would outweigh the cost for a 5-year-old car with 80,000 miles.

    YMMV
     
  3. mrbigh

    mrbigh Prius Absolutum Dominium

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    About the LED
    For the use on interior illumination= is a plus, common LED replacement assemblies are brighter, and that is sufficient for me.
    In the case of forgetting one door semy close, with the interior light on, it will save your AUX battery because the drain on the LED is minimal
     
    alekska likes this.
  4. Mike500

    Mike500 Senior Member

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    I'll stick with what came with the car, unless the thing is a direct "plug in."

    I like simple and cheap to replace.

    I don't really like the look of led's on running lights. I just see them as an expensive thing to replace, if needed.
     
  5. fuzzy1

    fuzzy1 Senior Member

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    It won't actually save the 12V battery, if left on for an extended period. But it will greatly extend the time available to discover and remedy the problem before the battery is drained. With proper LEDs (selected for lower current, not higher brightness, than the original incandescents), the battery should survive 5x to 10x longer, so it won't go dead overnight.
     
  6. mrbigh

    mrbigh Prius Absolutum Dominium

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    That's the point I was making and I can school about it because of the unfortunate experience.
    Replacing all the interior lights will consume not even half the wattage of a single incandescent bulb in a long period of time, 10 hours for the misfortunate event.
     
  7. ChapmanF

    ChapmanF Senior Member

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    There is a page on the PriusChat Wiki with lighting specs and general LED info for Generation 1 (for other generations the specs will be different of course, but the general info applies).

    One of the surprises was that the LED assemblies were not as commonly brighter as you might think, in fact for some cases it was pretty hard to find LED options that could match the original incandescent for lumen output.

    For example, the incandescent dome light in a Gen 1 is rated around 90 lumens, and for LED replacements in the same 31mm festoon style, the only ones that could equal that were designs where the circuit board stuck out both sides to carry 9 LED chips, and those would not easily fit in the dome light fixture. Granted, LED state of the art has probably improved since the last work on that page, but the takeaway is still that you have to be a pretty careful shopper to find LEDs that really are as bright or brighter than what they replace (and don't just seem that way because you paid for them).

    -Chap
     
  8. fuzzy1

    fuzzy1 Senior Member

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    But that analysis falls quite short. The great majority of those omnidirectional incandescent 90 lumens strike inside the lamp housing, getting absorbed instead of directed or reflected into the cabin. LEDs are directional, with the great majority of their lumens within a 90-150 degree cone aimed towards the cabin. So that 30 lumen LED could still provide more cabin light than a 90 lumen incandescent.

    Therefore, flux density measurements (e.g. candelas) in the desired direction are more useful than total radiated flux (e.g. lumens). But not being an optical engineer, I'm not peaked on the many measures and units used.

    While playing with several different products and formats, I settled on single-direction lamps that used 10% to 15% of the current of the original incandescents. Some multi-sided lamps, e.g. those with LEDs pointed in five different directions, were bright enough but used closer to 50% of the original current, most of it wasted on omnidirectional light. Those would not achieve the 5X-10X improved time to battery failure, so I didn't leave them in.
     
    #8 fuzzy1, Apr 9, 2015
    Last edited: Apr 10, 2015
  9. ChapmanF

    ChapmanF Senior Member

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    Your point's well taken, in that an empirical test in the cabin with a light meter would be a useful check on calculations done in the abstract. The point is it's important to do one or the other (or both), not just throw in some LEDs and assume that's an improvement on the original spec. It's typical that the lens/reflector combos that were designed with omni sources in mind are set up to reflect the light in the needed directions ... almost as if the people paid to design them had heard of the effects you're pointing out.

    That's especially important for the outside, legally required lights and signals, where the lens and reflector are carefully designed to meet the legal requirements for uniform illumination of a specified lens area, using the original omnidirectional source, and aren't likely to meet those requirements if the source is replaced by something highly directional, or even the "omni" LED assemblies with chips facing in a half dozen directions or so. Sometimes the results can be, e.g., taillights that to a following car just look like some bright isolated points instead of like taillights.

    It's easier to go all experimental on the interior, where there aren't safety regs to fall afoul of.

    -Chap
     
  10. fuzzy1

    fuzzy1 Senior Member

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    All my LED replacements have been inside, starting with the lights that could drain the 12V battery. The 'reflectors' behind them have varied between poor and nonexistent.

    The outside lights, with the well designed reflectors to meet legal requirements, are far less likely to suffer user errors that drain the 12V battery. I haven't changed any of them.
     
  11. qdllc

    qdllc Senior Member

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    Wow. I thought there'd be more LED enthusiasts for the Prius. I suppose it's more about tech or style than anything else.

    LED headlamps? I know the top-level Prius comes with it, but heck, I've got LED DRLs on my Prius Two (new standard for 2013), and those are sweet by themselves. I see no need for HIDs. My stock halogens do fine. Heck, I put HID on the motorcycle, and while an improvement (one lamp to see by), I question if it was worth it given how little night riding I do anymore.
     
  12. mrbigh

    mrbigh Prius Absolutum Dominium

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    There are several ebay sellers with pre-packaged led assemblies(KITs) that are plug and play at a very reasonable price.
     
  13. ChapmanF

    ChapmanF Senior Member

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    I don't think it's any shortage of LED enthusiasts ... I refitted the whole interior of a gf's boat for all LED lighting 20 years ago before it was cool and everybody came out with "plug and play" kits.

    It's just that doing your car is actually still a high-think job. The ebay sellers with "plug and play" kits only need to care about selling product; you as the buyer are the only one who cares whether it will perform suitably in your car, and without a good amount of homework you can easily end up getting several different kinds of disappointment for your money.

    The wiki page I linked earlier is intended to help you think about the right things to not be disappointed. Its specific part #s and specs have to do with the Gen 1, but all the general considerations still hold.

    -Chap
     
  14. Stephen Ryan

    Stephen Ryan Junior Member

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    I purchased my car used and the previous owner has replaced all of the interior lights with LEDs. I hate them... I don't know if he just chose an inexpensive light or what the deal is but the map lights flicker and they are an extremely annoying color. They border on the blue side of white and I will be replacing all of them shortly.