Anyone know the watt draw of interior LED lights?

Almot wrote:
Yeah, but measuring lumens will be tricky ;)
It appears that Chinese manufacturers make those lumens numbers as they go. Here is 48 board from the Ebay store that sells a lot of LED lights. Naturally, a lot of people here have bought it there - which doesn't mean anything, it can't be no better than the next guy, he just sells a lot. 48 LED, 240 lumens. Check his "other items" and you will see 24-board with 350 lumens. Yes, sir - 1.5 times more light with 2 times less LEDs. Same warm white color. One of these lumens numbers is wrong, and God knows which one.

18 watt regular bulb from Camping World has rating 264 lumens, 1.4A. So the closest equivalent in brightness (i.e. lumens) is 24-board... or 48-board. I tend to think that 350 lumens for 24-board is a bullsh-t, and the closest equivalent to 18W bulb is 48-board. So 48-board should not draw more than 1/3 of 1.4A, or 0.45A (because average quality LED is 3 times more efficient than regular bulb). If it draws more, than you've got a lemon.

I believe the 24 LED board you're comparing to the 48 LED board has the 5050 diodes, dissimilar to the 1210 diodes on the 48 LED panel, hence more lumens.

double post

Yeah, but measuring lumens will be tricky ;)
It appears that Chinese manufacturers make those lumens numbers as they go. Here is 48 board from the Ebay store that sells a lot of LED lights. Naturally, a lot of people here have bought it there - which doesn't mean anything, it can't be no better than the next guy, he just sells a lot. 48 LED, 240 lumens. Check his "other items" and you will see 24-board with 350 lumens. Yes, sir - 1.5 times more light with 2 times less LEDs. Same warm white color. One of these lumens numbers is wrong, and God knows which one.

18 watt regular bulb from Camping World has rating 264 lumens, 1.4A. So the closest equivalent in brightness (i.e. lumens) is 24-board... or 48-board. I tend to think that 350 lumens for 24-board is a bullsh-t, and the closest equivalent to 18W bulb is 48-board. So 48-board should not draw more than 1/3 of 1.4A, or 0.45A (because average quality LED is 3 times more efficient than regular bulb). If it draws more, than you've got a lemon.

A six dollar ammeter from Harbor Freight will get you a close figure for the amps being used. Put the meter in line (series) with the load you want to calculate. Amps x Volts = Watts

Measure the current with multimeter. Current times 12 = watts.

Almot wrote:
Measure them. It varies wildly, but on the average you may count on 3 times less watts per same amount of lumens as in incandescent bulb. Not that the numbers for lumens quoted for "China boards" with those 48, 24, 9 etc LED are very accurate.

How should I go about measuring them?

Measure them. It varies wildly, but on the average you may count on 3 times less watts per same amount of lumens as in incandescent bulb. In other words - per same brightness. This is - ignoring differences in color temperature which always exist, and affect the brightness (bluer lights feel brighter than yellower lights). Besides, the numbers for lumens quoted for "China boards" with those 48, 24, 9 etc LED are not too accurate.

My panel type LEDs draw about 0.2 Amps each

I have a bunch of panel lites (9 led) that draw .13 amp.

This is what I found when I did a test on 48 panel led and 1141 bulb.

The 1141 bulb----1.39A



The LED bulb-----0.25A

Maybe you can do the watts thing from this info.