How many amps do i need to power two LED Cob 9v bars ?

I was wondering how many amps would these two LED bars need in order to work if connected in series, and would a regular 9V battery be enough to power them ?

http://www.dx.com/p/high-power-3w-7000k-200lm-white-led-puri-chip-emitter-metal-strip-12-14v-65783#.VgrNC9RXeK1

What kind of battery should i use if a 9v isnt enough ?

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iceng2 years ago

You need a minimum of 18VDC at 1/4Amp.

It could be done with two 9V batteries also in series, But why not run each on its own nine volt battery.

Also you will only have a few minutes time on an alkaline battery and the cost of a Li is prohibitive.

Try 6 AA batteries in series as a minimum and run the lights in parallel.

9V-capacity.png
TarikS5 (author)  iceng2 years ago

Because of very limited space, 6 AAA batterys should work but I dont know how long would they last.

iceng TarikS52 years ago

A typical alkaline AAA has a 860–1,200 mah rating so at 250ma times two sets is 500 ma.

860ma-hrs/500ma = 1:43 low end to 1200ma-hrs/500ma 2:24 high end..

An AA Battery can deliver 2600ma-hrs/500ma = 5.2hrs => 5:12

Your answer is within your question.
If they are 9V and each has 3W they need at least 660mA to work - far more than what a 9V battery can supply.
Your link is not working, so I can't check the data for the LED's but if they are without the regulating electronics you will need a suitable LED driver board for them.

TarikS5 (author)  Downunder35m2 years ago