NeoPixels powing help

[rikkitheone]

i am making a halloween outfit for a party i am using 25 of the 12mm Diffused Thin Digital RGB LED Pixels and 2 NeoPixel Ring - 16 led and am running it on a arduino duemilanove i was think on getting 3 of http://www.ebay.co.uk/itm/7V-24V-5V-3A- ... 4179d0059e one for the led 12mm one for the neopixel rings and one for powering the arduino it self will thay do the job

[adafruit_support_bill]

Based on the specs they should work - provided that your power source is sufficient. What are you using for batteries?

[rikkitheone]

i still looking into it i no i cant use lithium iron (health and safety) so looking at doing 2 12v usp battery in Parallel but im working out the current draw to see if i need 2 and working out it run time

neopixel 750ma x2 = 1.5amps

12mm Diffused Thin Digital RGB LED Pixels 60ma x25 = 1.5amps

total amp draw 3amp rounding it up to 3.5 so i got wiggle room

[adafruit_support_bill]

It's generally not a good idea to wire packs in parallel. But since you have 2 strips/strands with similar requirements and 3 buck converters, you can just power them separately. If they will all be controlled by the same processor, just be sure to tie all the grounds together.

[rikkitheone]

from my very rough working out

i work out that i would only be palling 1.1 amp at 80% efficiency of a 12v battery and i only need it to run for 2-3 hours one battery will do it at 7AH and it run for about 3 hours i work it out saying that i can only use 50% of the battery

[adafruit_support_bill]

Sounds reasonable.

[rikkitheone]

what is the best battery to use as a 12v ups battery is no ideal and not pocket friendly and 36AA battery it way to big and look in rs and digikey but there are expensive and have to buy more then one

[adafruit_support_bill]

7Ah @12v is going to be a sizeable pack in any case. LiPo has the best power density. There are some safety issues with them, but the current generation are much improved. NiMH would be the next choice. Radio Shack or any of the on-line battery vendors will have a good selection of NiMH packs in various voltages and capacities.