Questions about 5 Meter LED reel

I read it as being 5M in a single length. This is likely based on how much current vs length capability is built into the traces.. after 5m the amount of power the diodes draw in total could get the traces too hot. In other words the traces are likely rated at 12v 1.5amp. More in a row exceeds that.

To run them parrallel off of a single power source shouldn't be an an issue. 

 1.5a as right is hard to say really, we don't even have a lamp count

1.5 amp for 15ft of lighting seems ok to me. That's only about 6 incandescent bulbs

  So. It draws 1.5a?.. I'd want 1.75a to 2amp supplied. Two draws 3a? I'd look to a 4amp for each pair @ 5Meters ea.leg,10 meter total fed in the center of two sections...

I.e. if you feed power at the center of a 10m piece vs the end as expected I think you could run 10m total without too much worry....it's not exceeding 5m in branch length. (Unless they speak of center feed with the 5m???) The solder pad being full of solder at the center connection could be kinda important if it was small as the pad is now feeding twice what's expected.

Not pushing specs to the limit might be prudent for consistency if nothing else.. a 20% buffer I'd use 4.8m max

Adding resistance to drive them less intensely should only increase the life.

Even though the strips are "rated" at 2A, my experience is 1.5A is about right with exactly 12V from a bench supply.

You are reading the caution correctly, they're saying you can connect them in series. 

I tried it on the bench, and two 5 meter strips worked fine.  There was a minor temperature rise in the little traces at the power connection end, but nothing significant, about 5C. 

However, the one issue you will have is there will be a significant voltage drop throughout the string.  At the end the LED's will be considerably dimmer than at the start of the strip.  I just took one strip and shorted the far end, then measured the voltage when I pumped 1.5 amps into the other end.  I lose 5 volts along the way!  So, the second strip will be running pretty dim, and you'd even significantly affect the first string.

Wire them individually, you'll be happier with the results.

Thanks to for the replies. I hadn't considered the voltage drop. I think I'll go with wiring the strips from the center and check for heat buildup.

Rick

A single strip works fine without going from the center.  Consider the current flow, only the ones nearest the power connection experience the maximum power drop.  As you get farther away from the power drop, you're powering fewer LED's, so the current draw is less as well.  I've lit them up to check the strips before I chop them up for passenger cars, the entire strip lights fairly uniformly.

The issue with the second strip in series is you're drawing the full power for the second strip through the entire first strip conductors.  Not only that, but near the power source, you're actually drawing all the current for both strips, so what I posted above would really be optimistic as far as power drops.