Led street light

quique
quique Solar Expert Posts: 259 ✭✭
I bought a led street light, 30w, 12v. It came without an instruction manual.

I connected its red wire to a positive (12v) battery and its blue wire to the negative terminal.

All it did was spark a bit (the red wire when I connected it to the terminal) but the LEDs didn't turn on.

So I opened it up and disconnected the LEDs from the "transformer" and plugged in the meter leads and tried again:

Attachment not found.

The red wire sparked a bit again, but the meter only went up to 2.4v. I disconnected the red wire and the meter read 2.4 and slowly went down to 0.

Any ideas? :)

Comments

  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Led street light

    Does it have a photocell, (an "electric eye") that keeps it turned off until it's dark, or until the light is excluded from it? If so, cover it with black tape to keep out the light, energize the fixture, and wait a few minutes. These photocell circuits almost always have a built in time delay to prevent passing car lights, lightening etc from turning the light off and on.
    Beyond that, can we assume it's built for 12 Volt DC operation and not AC operation? Can we assume the + and - are connected as required and not in reverse? Seems you have little info to go on.
    Can you post make and model of the lamp?
  • john p
    john p Solar Expert Posts: 814 ✭✭✭
    Re: Led street light

    From looking at the sticker inside it appears to be able too operate on a voltage between 12 and 24. I think for sure that be DC volts. It has some electronics? to convert that to 60v and it seems to provide 1.6a .. If that correct thats about 100w. or a current draw from the 12v battery about 9a. this could explain some sparking if the input wires are touched onto the battery.
  • quique
    quique Solar Expert Posts: 259 ✭✭
    Re: Led street light

    Ok it's a 30w light. I got it working, turned out my 12v battery had a rubber seal on the negative terminal I hadn't seen...duh!

    Quick question, if i have a 12v, 80a battery, I should have 960w/2 = 480w store, right? Which means I can operate the 30w light for about 480/30=16hrs, right?
  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: Led street light
    quique wrote: »
    Ok it's a 30w light. I got it working, turned out my 12v battery had a rubber seal on the negative terminal I hadn't seen...duh!

    Quick question, if i have a 12v, 80a battery, I should have 960w/2 = 480w store, right? Which means I can operate the 30w light for about 480/30=16hrs, right?

    Glad you got it working, and yes, IF, that is IF, the consumption actually is 30 watts, and your battery starts out fully charged and is in good condition, 16 hours should bring the battery down to a 50% state of charge. But recharge the battery again ASAP so as to prevent sulfation of the battery.
    I would highly recommend measuring the current draw while the light is on, so you'll know for sure it's draw, it could be more, or it could be less than advertised, and also check any draw in the off mode to see id there is any standby draw, assuming it has automatic operation available.
  • KnowledgeSponge
    KnowledgeSponge Solar Expert Posts: 173 ✭✭✭
    Re: Led street light
    But recharge the battery again ASAP so as to prevent sulfation of the battery

    Here's a REALLY great explanation of battery sulfation I found. ;)

    http://www.boatelectric.com/sulfation.htm
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Led street light
    Here's a REALLY great explanation of battery sulfation I found. ;)

    That is a well written description of sulfation, as long as you disregard the claims about what a battery maintainer/desulfator is capable of doing.
    Those claims are unproven on the basis of rigorous testing, are of questionable justification based on how they are supposed to work, but can't hurt a battery and have been reported to work by a large number of people. Caveat Emptor.

    Oh yes, and:
    Because hard lead sulfate is a non-conductive material...
    ...
    Also, when crystallized lead sulfate grows to a large size on the plates, it precipitates from the plates when it is large enough and accumulates at the bottom of the battery case. When this accumulation touches the plates, it shorts out the battery.)
    :confused:
    SMA SB 3000, old BP panels.