Electronic – how to provide light for multiple 12 v led lights for 2 weeks

12vbatteriesledlightvoltage-regulator

I'm participating in an art show soon in which I am making "sculptural light paintings" of which require a few 12v LED strips. They're the kind that work in aquariums and car's taillights and whatnot, and look like this;

green led light strip

I have about 3-6 lights being used per sculpture. So far my idea is to solder each one of them to an individual battery pack (so 3-6 battery packs per sculpture) that holds an A23 12 volt battery, and then connect each battery pack to a communal switch to turn all lights on and off at a whim to conserve energy. The LED strips vary in length (despite all being 12v) ranging from 20 inches long to 6 inches long.

As this is an art show, I prefer to not have any kind of outlet going into the wall as it really takes away from the look of the work, hence the battery packs. That being said, i also need the LEDS to be reliably powered for 2 weeks and active from 9-5 each day. Do you all think that this may be possible or will a different energy source be more efficient?

So far i have a test led strip lit up via 12 volt A23 battery that has been going for about 2 days now with no problems, but that's my only finding. I'm quite lost as I know this will all work in theory, but I'm not sure it's reliable in duration.

Best Answer

One single large battery will be easier to deal with, and will also make it easier to switch all the lights on and off.

To determine how big a battery you need, do the math. Add up the current requirement of all the lights. That's the current the battery must deliver. Now divide the battery capacity by that current to get a time. That's the time, in theory, that the battery can deliver your current for. However, for off the shelf 12V lead-acid car batteries, you want to avoid running them very low because that will cause permanent damage. Either get a larger "car" battery, or a lead-acid battery specifically designed to be able to be drained to nearly empty. Such batteries are called deep cycle, or are sometimes sold as marine batteries.

For example, let's say all the lights together draw 1.3 A (just picking a number out of the air). A 50 Ah car battery can supposedly run the lights for (50 Ah)/(1.3 A) = 38 hours. However, let's consider only half that actually usable for a consumer level car battery, so 19 hours. You'd need to get a bunch of such batteries to last the 112 hours you want. In fact, (112 h)/(19 h) = 6, which is how many 50 Ah "car" batteries it would take.

Since you say you only need to run the lights 9:00-17:00 each day, a better solution is to use a single battery and charge it overnight. Presumably the gallery or whatever is closed during the off hours, so it doesn't matter how it looks with a cord running to a outlet during this time.