LED strip wires burning?

I was trying to install these LED strips to my car (i was going to wire them to my interior lighting fuse to use them as puddle lights)

the LED strip says it needs to be wired to a 12v connection.

I'm told by my father that the car's battery is 12V.

I went ahead and touched the negative first, then i touched the positive, the positive started to burn/spark

is this suppose to happen? why did this happen? is it because the wire and the battery did not have a SOLID connection?


please help. i want to understand electronics better

 

[97sprt4x4]

Yes, if you were only close to the positive, it will try to arch causing the sparks. if you have the wires wired up without current going through them, it should avoid sparks when they're actually turned on.

Justin

 

[Nixthebomb]

Straight to the battery? that'd be your issue, instead of going through a fuse to lower the amperage on the 12V it gave every amp in the battery through that small wire, thats why it's always important to fuse things coming off a battery.

 

[Jason c]

I just ordered a set of 100cm strips to light up my sliders/steps the same way. I am interested in how this turns out. Can you post pics when you are done?

 

[deuce07]

i wired them to the fuse like i wanted, but they wouldn't turn off because there is always power running thru the fuse.. i think the only way i could have it turn on/off is unless i tapped into one of the interior lights

 

[Maniak]

Straight to the battery? that'd be your issue, instead of going through a fuse to lower the amperage on the 12V it gave every amp in the battery through that small wire, thats why it's always important to fuse things coming off a battery.

Connecting the LED strip's own wires directly to the battery is fine. The Battery doesn't "push" power to the device. The Battery has a bunch of stored energy and the LED strip will only pull as much power as it needs.

The LED strip should pull very little power, so if you got a small arc, that can be normal as connected it to the battery.

~Mark

 

[Jason c]

Wiring to the door switch might be easier then the bulb itself. That is where I was going to connect it.

 

[greyphox]

Straight to the battery? that'd be your issue, instead of going through a fuse to lower the amperage on the 12V it gave every amp in the battery through that small wire, thats why it's always important to fuse things coming off a battery.

Not quite true. While fusing them is a good idea if you are running them directly off the battery, fuses don't do anything to lower the current flowing unless the current exceeds the fuses rating. In that case it will just blow, and thus you will have 0 current.

Also, a car battery is only 12V with the car not running. When the engine is on and the alternator is charging the battery, the voltage will be closer to 13.5-14V. Sensitive electronics don't like changes in voltage too much. LED's are current driven devices; this means that the amount of current directly dictates how much light they will emit (ie their brightness). One characteristic of this is that a small change in voltage results in a large change in current. Thus for a little extra voltage, the LED will get A LOT brighter, and also must absorb more power and produce more heat. Prolonged exposure to high currents (and subsequently high heat) will drastically shorten LED lifespan. In other words, apply as close to the required voltage as possible.

Since this is a strip, it will be pre-fabricated with current limiting resistors to allow the LEDs to survive 12V and last a long time. Unless you got some nice high dollar ones with a built in constant current source......but thats for another day

On to your problem of them staying on all the time. One way to do this is to get a rocker switch and put it somewhere easily accessible. Just wire it to the load side of the fuse (if you pull the fuse out of the socket, take a voltmeter to the 2 sockets. The side without voltage will be the load side that you will want to connect to.) and then from there put a switch in series with the LED strip to cut it on and off. Wire the other side to ground.

Also, you could just tap into the interior lighting wire and have the LEDs act just like the other interior lights.

[+]---------*~*---------/ -------|>|--------[-]
Positive.......Fuse........Switch.......LED.........Ground

 

[BrianDye]

I have LED strips attached to my parking lights, AND my interior lights, no fuses, straight up spliced into the dome lights, which was a breeze....had them for a good 5 months or so and theyre great...