PROJECT QUESTION FOR CUB LIGHTS

[garvey76]

OK here are the spec of the lights i am using
20x LED X 3.5V/0.06W 2.2M CABLE
MY QUESTION IS
Can i strip the end of the battery box (using x2 aaa) to power lights, and fit a deans connector to fit lights on to a 2 cell lipo from a blade cx2 (no spec sorry) or use a y plug and connect to my 3 cell 1300.
will the lights blow or the battery catch fire?

not good with electrics and the battery box with the lights is a bit heavy and bulky so using the 3 cell lipo or a seperate 2 cell would help.

thanks all

[garvey76]

ANYONE

Not sure if the question is clear

i have a 2.2m string of 20 LED lights that run off of a small battery pack (2 AAA batteries)
i want to ditch the battery box and connect the ends to a 2-cell 7.4V 800mAh Li-Po/ or use a y lead and connect to my 3 cell 1300 lipo i use in cub.
the lights are 3.5v / 0.06w
will they blow if connected to the lipo or will the lipo blow

any advise would be great full as i am totally dumb with electrics
thanks

[duck9191]

led arnt dependent on voltage, they are a current controlled device. if you just hook one up to a battery it will turn on, but due to a crappy thing called thermal runaway the led will keep drawing more and more current untill it over heats and dies.

so, to stop this you need to use a resister to limit the current. to do this you need to know some specs of the led, the forward voltage and the max current and the source's voltage. there are a bunch of led calculators out there that will tell you what resister you need. ill find one when you find the information on the leds.

also if you plan on keeping it in the string of lights, you will need to use a voltage regulator to get the voltage down to 3 volts so that the built in resisters will work correctly. you can use a lm317 which is a adjustable voltage regulator.

[garvey76]

;D WOW THANKS DUCK
as this was a set bought from a shop already made up and running off of a box housing 2 AAA batteries, wouldn't all of the above be covered

or is most of what you said in the battery box so when i remove it then it will need replacing to work again.

i can see a small blue resister next to the first bulb, im guessing the regulator is in the box
and so when i take it apart all i need do is connect y lead to the regulator if its some sort of small pcb and plug in to battery no....yes.....its all confusing.

[duck9191]

the resister is set up to limit the current for all the leds, so as long as you keep the hole thing together you will be fine with that. you just need to get the lipo's out put down to 3volts as thats what the two AAA's were and what the resister was set up around.

here is a uk supplier of the lm317 voltage regulators.