yankeedoodlepigeon Posted May 14, 2012 Report Share Posted May 14, 2012 Hi All. I have nearly finished refitting my boat and I am doing the lights. I have ran 5 12v led lights in a row and someone said that I need to put a resistor on first as they are different to normal lights and will burn out if I don't. This is just one of the 5 lights. http://www.ebay.co.uk/itm/G4-24-SMD-LED-Marine-Camper-Bulb-Lamp-12V-Warm-White-Light-Car-/260948157084?pt=UK_Light_Bulbs&hash=item3cc1b8e29c#ht_1189wt_1110 Could I run them direct off a car battery or will I have to fit a resistor? Thanks Ydp Quote Link to comment Share on other sites More sharing options...
WelshLamb Posted May 14, 2012 Report Share Posted May 14, 2012 Ive fitted them before now straight off a battery, with an inline fuse Quote Link to comment Share on other sites More sharing options...
HDAV Posted May 14, 2012 Report Share Posted May 14, 2012 Yeah you need a current limiting resistor unless there is one built in. Quote Link to comment Share on other sites More sharing options...
HW682 Posted May 14, 2012 Report Share Posted May 14, 2012 (edited) A basic LED chip needs about 2V to operate, and so requires an inline resistor to use on a higher voltage supply. As this is a sub-assembly that is marked as 12V input then it would suggest that you don't need anything else. Edited May 14, 2012 by HW682 Quote Link to comment Share on other sites More sharing options...
alastair0903 Posted May 14, 2012 Report Share Posted May 14, 2012 (edited) I thought the only reason for fitting resistors to led's was so that when you are indicating they will register on the dash to let you know your indicators are working . I tow some trailers at work with led's and no resistors and they are a pain as you don't know from the cab if your indicators are actually working , don't think you will do the lights any damage without resistors Edited May 14, 2012 by alastair0903 Quote Link to comment Share on other sites More sharing options...
northeastshooter Posted May 14, 2012 Report Share Posted May 14, 2012 as said these are 12v leds so will work direct of 12v supply as they have a resistor already built in so you will be fine Quote Link to comment Share on other sites More sharing options...
HW682 Posted May 14, 2012 Report Share Posted May 14, 2012 I thought the only reason for fitting resistors to led's was so that when you are indicating they will register on the dash to let you know your indicators are working . I tow some trailers at work with led's and no resistors and they are a pain as you don't know from the cab if your indicators are actually working , don't think you will do the lights any damage without resistors What you are describing is a resistor in parallel with an LED bulb, to draw more current so that various car circuits recognise the load. It is different from the series resistor, which is needed to operate a simple LED at 12V. (These assemblies don't need one though) Quote Link to comment Share on other sites More sharing options...
david_r Posted May 15, 2012 Report Share Posted May 15, 2012 Surely if they're 12v rated lights and you're running them from a 12vdc supply, they'll need to go in parallel, not series, otherwise they'll be very dull. Quote Link to comment Share on other sites More sharing options...
HDAV Posted May 15, 2012 Report Share Posted May 15, 2012 Interesting having read the ebay advert: Do not replace it with halogenNeed led light transformer LED light transformers arent all the same I have seen from 12-48V and depends if they need constant current (350mA or 700mA being common) or constant voltage (12-48) depends on whats built in to the device some will run direct others wont. Very light on details and spec Quote Link to comment Share on other sites More sharing options...
stokie Posted May 15, 2012 Report Share Posted May 15, 2012 I've just swapped the lights on my boat to LEDs . I just simply replaced the old bulbs with a same fitting element and they work fine . Pulling loads less current and putting less drain on the batteries Quote Link to comment Share on other sites More sharing options...
yankeedoodlepigeon Posted May 23, 2012 Author Report Share Posted May 23, 2012 Well I fitted the lights in series and soldered them in today and they didn't work for some reason they will only work if wired up parallel. This is a problem as all the wiring is now behind the carpet liner covering the ceiling and sides. Why would they not work wired up in series not matter what way round I have tried them? I have not got a clue about electricity and its sent a few of my friends home scratching chins. Regards Ydp Quote Link to comment Share on other sites More sharing options...
handy4454 Posted May 23, 2012 Report Share Posted May 23, 2012 Hi Ydp your lights need to be wired in parallel as they have drivers built in,thats the reason they will not work in series,they are not polarity concious so will work with the leads connected either way round but they must be connected to 12 volts atb handy Quote Link to comment Share on other sites More sharing options...
yankeedoodlepigeon Posted May 23, 2012 Author Report Share Posted May 23, 2012 Thanks handy. That solves that problem. I just have to re-wire it now Quote Link to comment Share on other sites More sharing options...
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