Originally Posted by honda03842
I had upgraded all our incandescent bulbs to a 1156 LED replacement. The replacement LED lamp has 64 LEDs. I recently purchased LED Bulbs with 102 LEDs that are brighter than the 64s.
I bought them on EBay. I think they were about $3.00 for 2 bulbs plus shipping. I looked recently and there are even more densely packed bulbs available now.
Since the number of LEDs is not necessarily proportional to brightness I installed one of each over the table and the 102s are visibly brighter.
Just for comparison these are the specifications for the lamps shown in my original post. I bought the " warm white" which has a color temperature of 3100*k. I was looking to replace the incandescent bulbs (921) which have a wedge base and draw about 1.5 amps. Prior to installing them, I tested them with my bench power supply. I found their intensity does not change down to about 10.5 volts. With a "dead battery" they should still light
up. That, as well as not being polarized, using high efficiency LEDs, and being compact is why they cost so much more.
G4-xWHP15-DAC: White LED Lamp
Disc type G4 base Lamp with 15 High Power 5050SMD LEDs
12 Volt AC or DC
Produces 180/160 lumen at 7000K/3100K, 120 degree beam pattern
1.75 inch diameter, Connection Pins exit side of lamp
Price for each. $ 16.95
Fifteen white LEDs wired with the appropriate current limiting resistors should cost quite a bit less.
The lamps from eBay contain 102 white LED's. Typically each LED requires about 3 to 3.5 volts at about 20 mA to 30 mA. That gives a power dissipation of between 60 mW and 105 mW per LED or between 6.1 watts and 10.7 watts for just the LEDs. Some sort of current limiting circuitry adds to the power dissipation.
In rough numbers I am guessing the current drain is about 1/2 to 1 amp per bulb. While they are certainly more efficient than an incandescent 1156 bulb, I would think they will draw too much current to be an efficient replacement (in terms of battery
life) inside a trailer. Since they are a tail light replacement I bet they are very bright. Can you measure the current just to satisfy my curiosity? Raz