Instructables

How to properly power LED Strip Lights using battery for mobile sign?

Hello and thank you in advance for any assistance you can offer me here.  I'm clueless here...

So, here is the plan, I have purchased a strip of LED lights (see them here:  http://www.amazon.com/dp/B005EHHLD8/ref=pe_385040_30332190_TE_tr_3p_M3T1_ST1_dp_1) and am attempting to place them on a mobile sign.  Imagine a person walking around on the street after dark with a sign that is nice and bright with LED strip lights.

Obviously, these need to be battery operated, and I have seen it done with something like a cell phone battery and charger type thing and would like to duplicate that.  I do not know how much power the battery would need, or if resistors would be needed (or even how a resistor works).  Can anyone provide more insight for me?

Thank you again!

steveastrouk10 months ago
How long do you want to operate the lights, and how much of the strip do you want to use. To run the whole length will take nearly 25 watts. If you run it off a modest car battery, it wouls run for around 24 hours perhaps.
jenneee (author)  steveastrouk10 months ago
Hi Steve and thanks for your interest in helping me!

The most I would need this to run would be 3 or 4 hours. I've seen it done with something as small as a rechargeable cell phone battery that is actually attached to the sign. It would be hard for a person to carry a car battery and this will be a mobile sign that someone would be holding.
A phone battery wont supply the necessary voltage. You need 12V, and around 10Ah from the battery. If weights a major issue, here's a perfect solution.

http://www.ebay.co.uk/itm/KDQ4-EU-plug-9800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-SPC-2261-/331039702802

I am sure you can find an Ebay.com equivalent.
jenneee (author)  steveastrouk10 months ago
This is exactly what I was looking for! But let me ask you this if I can, there is another one that is a 6800mAh... would that be sufficient, OR IS THE 9800mAh the requirement? There is about a 15 dollar price difference and the reviews of the 9800 say that they really don't carry that charge amount. Thanks again for your help!
It will run your full strip for at least 4 hours. I don't necessarily say THAT battery is the one you should get, but its certainly one that ought to meet your spec.

For every hour you want to run the lights, you need 2AH, 2000mAh of capacity in your battery . 6800mAh will give you 6.8/2 hours of life.

The spec on my link IS pretty stupid ;-)
iceng jenneee10 months ago
Then get a 1/6 of a modest car battery.
You should be able to carry that weight for 4 hrs :-)
You will need a 12 volt 12 amp hour battery and just connect + to + and - to -.

Joe