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# Can I power a 300 led strip of 5630 led's with 8 AA batteries? The led's are controlled by an RF remote. Answered

IF 8 aa batteries do not supply enough current, should I go with 2 or 3 groups of 8 in parallel? Or do I need to use 8 C batteries, or 8 D batteries, or possibly 2 6 volt lantern batteries.

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## Discussions

Read the data sheets and do the maths!

As you left out a lot of details, let me start up my crystal ball...

I'd guess the 300 LEDs are in groups of 3 with a resistor for each group. So the strip will run with 12V (that matches your 8 x 1.5V batteries). The strip will have 100 strings of LEDs in parallel.

Next I guess that the LEDs will be driven with 50mA. Time 100 that means that the 300 LEDs need a whooping 5A to run. (Even with only 20mA that's still 2A)

A normal alkaline AA battery has about 1.5Wh of energy or 1Ah of charge.

So yes, those batteries could drive the LEDs for about 12 minutes (or half an hour in the 20mA case). This is of course an optimized calculation, not taking into account any internal resistances, the voltage drop as the batteries empty etc etc.

Thanks for your help and yes they do need 5A to run, so that 8 AA batteries are out and I would have to go with either 24 or 32 AAs. I know that 2 6V lantern batteries will work and I may go that way. What about 8 C or 8 D batteries?

Some lantern batteries are internally made of D-cells.
How long will they last? Find the capacity and do the mathematic. It's just multiplication and division.

But anyway, if you want to use this for a longer time, you should think about using secondary cells instead of primary ones (rechargeable accumulators instead of one use batteries). A automotive lead acid battery will last substantially longer and can be recharged again and again.

I have been contemplating a 12v rechargeable battery, I'm sure that's the way to go. I'm looking at an Amstron HR 1234W 9A and I like the 2 yr warranty. Not a bad price, \$12.99 at atbatt.

Do your math the simple way:
Take the max current your LED system will use, e.g. all LED's at full brightness.
Take the max time you would need to have them running.
Multiply these two numbers in ampere and hours to get the AH value you need for the battery.
Example: 5A for the LED and you need at least 6hours of run time between charges.
5 x 6 = 30AH
So the battery in question must be able to provide at least 30AH of power but also be able to provide the 5A with no problem.
Since you use LED's that run on 12V this all you need to calculate the battery and running times.
But as a battery reduces the voltage while discharging you should opt for a so called "Deep Cycle Battery" - they are often used for solar systems and as the second battery in 4WD's.
Unlike normal batteries they are designed to provide a lower ampere output than a starter battery but where the starter battery is down quickly the deep cycle battery takes much longer to go belo the 11V mark.
It also pays off to get the battery one size bigger than calculated to care for aging and cold temperatures, so here instead of 30AH I would opd for 45AH.

I use one of these for my LED strips. It powers a full 5meter strip for the whole day. Love it. http://amzn.com/B007RQW5WG