Connecting 5M LED reels together

The 5meter strings are designed in groups of 3 LEDs connected in

parallel.There will be a voltage drop after each group of 3 LEDs so

by the end of the 5 meter string the voltage may be too low to light

the 3 LEDS in the group to full brightness. The simple answer is that

a full string of 5 meters may not have full brightness at the end and any added strings will have reduced brightness or not light at all.

There is no maxium number of LEDs that can be connect together.

Rope strings of Christmas tree lights are rated for up to 20 strings

connected together but that is a different wiring system. There is

on rating for 5 meter string. Try connecting more than 1 5 meter

string together, it might work but don't count on it.

I've connected three strings together (just as a test five minutes ago), and I didn't seen any significant fall-off in light levels.  However, note that the traces near the power source are carrying 6 amps, which I suspect is more than they're actually designed for, so it's probably not a really good idea.  I have to agree with the previous post, I'd limit the series connections to one 5 meter string.

I'd just power each string separately, run the wires for the extra strings directly from the power source.

After doing some testing there is about .5 volt drop per 5 meters so

with 4 5 meter strings there is a 2 volt drop and the LEDs are still blinding.

Connecting 4 or 5 string will work with some reduction in light output by

the end of the string. If the light output is too much, connect 12volts to both

ends of the string.

I didn't think to measure the voltage drop, that was an obvious oversight.   1/2 a volt isn't all that much.  However, the more strings in series, the higher the voltage drop across the first string will be, ohms law to the rescue.   By the time you get to four or five strings in series, I'd expect there to be some adverse effects to the first string.

I only had three reels of them handy, so that's what I tested.

Thanks to all who responded. It seems to me the weak spot is the copper wire traces which are OK for 1 reel but not substantial enough for the additional current on a constant basis.

Rick 

Correct Rick, I'd run parallel wires if you want a bunch of them in series.