Battery Question for Lighting Costume

[Xenagal01]

Hey Everyone!

I'm creating a costume and want to incorporate a mess of LED lights. Not sure how much power I'll need quite yet, but I'm looking for a battery pack that will allow for power all night. Ideally one that can be plugged into a generator to charge. It would probably be fixed into a backpack that I would carry around; so no more than 10lbs would be ideal. Any and all suggestions a greatly appreciated!


Nics

[junglesmacks]

I ran 2,240 LEDs off of 16 AA batteries. I doubt you'll be surpassing that.

A simple combination of AA battery packs should suit you fine. Keep in mind that you'll need to match your source voltage to your LED string requirement. Have you worked with LEDs before? What is it exactly that you're doing?

[AdamOfTheRedEarth]

Probably pick up a SLA battery off of ebay. I got a 12ah 12v SLA battery from ebay.com for 25 bucks free shipping, it weighs maybe 7 or 8 lbs but it's relatively small, could put it on a utility belt if needed. I also got a 5ah SLA battery that is half the size and weighs maybe 3 or 4 lbs that could definitely be used on a belt. Go on ebay and type in 12v SLA battery and sort by price and then scroll through to find one that meets your budget requirements. If money is no object then go for a lithium-ion but you'll be paying much more for one that has the equivalent capacity of a sealed lead acid (SLA).

[BBadger]

A "mess" of LEDs can mean different things. How many amps/voltage etc. do you need for it? You could use RC NiMH battery packs, or some LiPo battery packs, or those SLAs mentioned above. I'd avoid alkaline batteries if you have somewhat high current draw, as their lifetime is shorted dramatically by high discharge.

[AdamOfTheRedEarth]

A "mess" of LEDs can mean different things. How many amps/voltage etc. do you need for it? You could use RC NiMH battery packs, or some LiPo battery packs, or those SLAs mentioned above. I'd avoid alkaline batteries if you have somewhat high current draw, as their lifetime is shorted dramatically by high discharge.

In my research I decided to go with the SLA batteries because they're relatively cheap and have good ah ratings. I read too many horror stories of LiPo (lithium polymer) batteries catching fire and that's the last thing I want to have strapped to my person. I will have to check into the RC NiMH battery packs because it would be nice to have something to make some hats with that doesn't weigh too much.

[junglesmacks]

If you're just making hats, then seriously.. a few AAAs will do you just fine. No need to complicate things. This isn't rocket science.. just some little blinky lights..

Make sure to only get good Duracell copper tops though. They blow away anything else, even the lithiums.

BTW the whole rumor mill about LiPo's catching fire has to do with muti-cell units being incorrectly charged. They don't just spontaneously combust out of nowhere. The problem though is charging them. I can almost guarantee that with normal use, you won't have to change your set of Duracells all week long.

Put it this way: The first year of building an LED suit, I used 1200 LEDs total running at 18v using 12 AA batteries. I changed them once on Friday.


KISS: KEEP IT SIMPLE, STUPID

[oscillator]

What JS said: KISS

Fwiw, the avg LED takes about 20 milliamps, and about 3 VDC to turn it on.

So, 16 LEDs will need 320ma. Check out Bucktoot constant current drivers. There are 350, 700, and 1000 ma versions. These alleviate the need for current limiting resistors, and play nice with various battery packs.

Shorei makes nice 12v LIFEPo batteries that can be used with low end chargers (Battery Tender). A 9aH is tiny.

[maladroit]

Li-Poly can also combust due to overcurrent during discharge, or mechanical trauma. But if you size your battery and loads correctly, it's really just very unlikely.

I normally like using the small rechargeable USB battery packs for everything, but on playa AA's are king.

I also don't care for the fact that an SLA weighing 3 pounds would provide the same capacity as a lithium pack weighing 1 pounds or an AA pack weighing 1.5 pounds. If you're worried about size rather than weight, lithium-ion batteries are less dense, so they would be half the size of an equivalent capacity SLA while AAs will be 1/3 the size.

[AdamOfTheRedEarth]

Thanks for the tips guys. I looked into those shorai 12 lifepo4 batteries, and yes they are lightweight and have crazy aH ratings but they are also expensive! They seem to run about 5 times the cost of a similar SLA battery, which is more than I want to spend on a battery that could very easily end up lost (putting one on my bike also and we all know what happens to bikes in BRC...).

As far as K.I.S.S. goes, that is exactly what I"m doing. You guys are at the next level, I'm a beginner and my plan is super simple. I'm using 3528 and 5050 SMD LED waterproof strips at 60 LEDs/Meter, these have built in resistors so it's truly plug and play, doesn't get any simpler than that. I don't know if you guys have worked with these but they are crazy bright but also suck up a lot of juice, at least the 5050 LEDs do. A full 5 meter reel (16.4 feet/300 LEDs) of 5050 RGB LEDs uses 6 amps or 72 watts at 12v DC (.24w/LED) and my 12aH SLA seemed to keep it near full brightness for at least 6 hours although I need to do another test and properly time it. My plan for a hat so far involves a battery holder with leads that holds 8 - AA batteries which will give me 12 volts to power maybe 2 or 3 feet of LED strips. I haven't decided on whether to use the 3528 or 5050 LEDs yet for my hat, I'd get triple the battery life on the 3528s but the 5050s are soooo wickedly bright . I bought a little switch controller gizmo that's about the size of a stick of gum (little smaller) that hooks up to the power source (battery in this case) and you just plug the RGB lead from the led strip straight into it. It has an impressive variety of modes and you can change to any color at any brightness also, only has little buttons so it's easy to conceal but offers great control over the RGB LEDs.

My projects aren't as cool as junglesmacks awesome suit but they're a little more than just a blinky light hat, if that was the case I'd just get one of those battery powered christmas light strings and stick it on a hat.

[maladroit]

It's impossible for a 12AH battery to run a 6A strip at full brightness for 6 hours. If, on average, only one color was on at a time or there was fading or blinking involved, then it would be possible.

[AdamOfTheRedEarth]

It's impossible for a 12AH battery to run a 6A strip at full brightness for 6 hours. If, on average, only one color was on at a time or there was fading or blinking involved, then it would be possible.

Yes I should have been more specific, I had it on color fading mode. After all, full brightness on all colors would be pure white light, not much point in using an RGB strip for that . So there was always one or more of the red green blue leds on at a given time but since pure white wasn't part of the color fading cycle the strip was never running full 6 amp draw on the battery. Thanks for pointing that out, I hadn't really thought of it until you said that, and I was also kind of wondering how it lasted so long but I didn't think about it too hard haha. This is all new to me, two weeks ago I had no clue on what an amp hour even was, or how RGB leds work, or any of this stuff. It's fun to play with though, that's for sure, and if I type too much or make incorrect statements I apologize but I'm learning still and no one in "real life" is interested in doing this with me so I have to nerd out on the internet instead!

[maladroit]

Remember that large quantities of LEDs can provide a striking effect even when they're running at 20% or even 10% of their maximum brightness. I suppose you can't exactly do that with your pre-built controller, but it's something to think about. I put 114 RGB LEDs pixels on a hat, and if I ran it at full brightness it would draw about 7 amps on full white. Instead, I ran the PWM to average less than 20% of that, and it was still far brighter than it needed to be. Instead of a 1000mAH battery lasting a few minutes (if at all), it lasts several hours.

[AdamOfTheRedEarth]

Remember that large quantities of LEDs can provide a striking effect even when they're running at 20% or even 10% of their maximum brightness. I suppose you can't exactly do that with your pre-built controller, but it's something to think about. I put 114 RGB LEDs pixels on a hat, and if I ran it at full brightness it would draw about 7 amps on full white. Instead, I ran the PWM to average less than 20% of that, and it was still far brighter than it needed to be. Instead of a 1000mAH battery lasting a few minutes (if at all), it lasts several hours.

That's a good point, I definitely want to have some "high impact" pieces but then I also want some stuff that will last all night long too. The LED controllers I have do allow me to adjust the brightness, but I wonder if what you're saying would be the better route, to have some sort of current limiter in line ahead of the controller to provide a steady wattage that is a good compromise between brightness and battery life. What would you recommend I use? Oscillator mentioned the constant current LED drivers, I suppose I should look into them.

As far as lithium-ion batteries go, that was my first choice but I was unable to find a 12v lithium ion pack with at least 10ah for a decent price. So far, I have a 5ah 12v SLA that weighs about 3.5 lbs that costs $15 w/ free shipping, a 12ah 12v SLA about 7-8 lbs costs $25 w/ free shipping, and a couple battery holders for 8 - AA's, I'm not sure on their ah capacity exactly but I was thinking about running two of those packs in parallel to double the amp hours while keeping it at 12v, at least for my high impact pieces. I also got some battery holders for 9v batteries which seem to have no problem lighting up a 5 meter strip of 3528 LED, so I'm thinking of using them for smaller strips of maybe a couple feet or less.

[maladroit]

If the controller has a brightness adjustment, then you probably don't have to do anything else. PWM dimming saves power automatically.

[BBadger]

If you're deciding between a current and PWM dimming, stick with PWM as it doesn't burn off power in regulating current. That is unless you're using a DC-DC converter in constant current mode, in which case it probably doesn't make a difference.

[junglesmacks]

Stay away from those 9v snap top batteries as they don't do high current very well and drop off like a cliff when drained. If you're going standard alkaline, then AA all the way.

Yeah.. RGB LEDs suck some serious juice and current which is why I'm sticking with single color for now since I like high amounts of lights. (OK.. more like a metric fuck ton of lights)

What maladroit said.. you could run those strips at a lower brightness level just fine and still be plenty bright and save battery life at the same time. Also think about maybe sequencing them to save battery life and spread out the effect. Just as an example and not to talk about my own projects, even though I had say 1200 LEDs that year, only 150 were lit up at any given time being as that they were split into 8 channels. Sequencing and spreading out the light can give the visual effect of lots of light but at a much reduced battery draw.

As far as the batteries go, I would stick to a nice bank of Duracell AAs and just change them out as needed. Pound for pound, the most battery life you're gonna get with ease of use and availability.

[junglesmacks]

I'm sure you know this but just covering bases. Each AA is 1.5v.. the string needs 12v.. so two of those 4-AA battery packs hooked in series will give you the 12v source voltage that you need. Just tape them together and solder the leads. Duracell, Duracell, Duracell. No Energizer lithiums.. don't believe the hype. They suck.

[maladroit]

Here's a great review. Pits 30 brands of AA batteries against each other, you get to see raw capacity, capacity under high drain, capacity versus price, energy per unit cost, etc. http://www.batteryshowdown.com/results-hi.html

[junglesmacks]

See.. I read that too, and was stoked to see how the Energizer Lithiums would do.. and they totally sucked compared to the Duracells. I also tried the Kirkland ones and they were even better than the ELs.. but not as good as the Duracells.

Leeeeestan to me, grasshoppa. Ol' JS knows what he's talkin 'bout.

[Roark]

I'm sure you know this but just covering bases. Each AA is 1.5v.. the string needs 12v.. so two of those 4-AA battery packs hooked in series will give you the 12v source voltage that you need. Just tape them together and solder the leads. Duracell, Duracell, Duracell. No Energizer lithiums.. don't believe the hype. They suck.

FWIW, the Energizer lithiums last about 3x longer than any other battery in an insulin pump and are specified by name by at least two pump manufacturers. I have to wonder if maybe these are designed for long-term /low-draw applications or something?

Dunno, but the shootout was an excellent read. Thanks for posting that!

[maladroit]

I'd probably never buy the lithium AA cells, I'd rather pay 25 cents for two batteries that I have to change versus 60 cents for one battery. I've had good results from Energizer, Duracell, and Kirkland, but will have to try the Ikea ones. Apparently they're just Duracell with rebranding and much lower price.

The lithiums only pull ahead when you really need to draw 1000mA from them all the time. Most LED stuff won't do that, and when I've needed those kinds of currents I switch up to C or D cells.

[AdamOfTheRedEarth]

Lots of good info in this thread, thanks everyone. I am also agreeing that AA's are the way to go for my smaller pieces, if nothing else than for the simple reason of ease of replacement (or procuring replacements if you're unprepared on the playa). However, AA's (as noted in this thread) are good for maybe a total of 1 amp of current am I right? This is enough to put on a good show with a certain amount of LEDs but for my bike I'm planning on lighting that sucker up with maybe 33 feet of LED RGB strips (two 5 meter rolls give or take) so my logic is that I need the best battery I can get for a reasonable price that is under 10 lbs and provides multiple amps of current draw (when desired, I can tone down the brightness to increase longevity when trekking across deep playa for example). I wanted to go lithium-ion because from what I understand the Li-Ion batteries don't drop off in power like the lead acids do (supposedly Li-Ion on a graph looks more like a flat horizontal line of voltage whereas a SLA would be a parabolic drop).

Thanks for the information about the PWM vs. inline power management. All of my LED controllers have brightness settings (PWM as it's called in the instructions) so I think that will be sufficient for my needs. As to Junglesmacks idea about sequencing the LEDs to only have so many on at once, I hope to get to that level someday, but for now I'm going to learn the ropes just by dealing with "dumb" leds. They also make LED strips with integrated IC's that can do some really cool stuff since they're individually controlled and the remote controller has 144 keys but the cost per meter (minimum $11/meter vs. about $3/meter for dumb) is much more than the dumb LEDs so for the majority of my projects I will be using the dumb LEDs. Something else I'd REALLY love to get into is the RGB LED Pixels, and I believe Arduino is how they're controlled. I can imagine some fantastic stuff that could be done with them but I literally am a noob at all of this stuff, I need to learn the basics of soldering and learn more about voltages and amps and gigawatts .

So my take away from this thread so far is to use AA for the smaller projects, preferably Duracell or Kirkland brand.

One thing that wasn't really discussed so far. What do you guys think about rechargeable AA batteries? I bought some from China that were supposedly supposed to be "Ultra Fire" brand but arrived with the label "Uitra Flrc" and they are about half of the weight of a Duracell, maybe less. They claim to be 3500 mAh (!!??!?) but I doubt that's true. They are Ni-Mh and say to charge them at 350 ma for 16 hours. I'm still researching a good AA battery charger to buy that can read voltages and charge to max capacity but for now I've been charging them with a "dumb" charger that charges at 500 mA for 4 hours at a time.

[BBadger]

Remember that if you're using alkaline batteries, that the higher the rate of discharge, the lower the effective mAh rating will be. Alkaline batteries are great for low-discharge (~100mA), long-term operation. That's why the batteries last half a decade or more in storage, but suck when used for applications such as powering digital cameras.

Discharging alkaline batteries at 1A will severely reduce their Amp-hours, requiring many more batteries than you may expect when judging by amp-hour ratings alone. If you're going to have high discharge rates, you may want to invest in NiMH type rechargeable AA batteries for your lights. They're more expensive, but they'll last you longer and you can just recharge them during the day (assuming you have a charger).

You can also buy battery packs, such as RC battery packs that have connectors and all that, along with high voltages and decent capacities. They can be either NiMH or LiIon/LiPo (those aren't the correct voltages you'd need, but are just examples). They will cost a bit more than the 48-pack of AA batteries, but they're high capacity and high discharge. Remember to get the correct charger for your LiIon/LiPo batteries, or they may burn or explode.

Finally, if you want to maintain constant voltage no matter what the input voltage, buy a step-up or step-down DC-DC converter and use that. They're very efficient and can supply high currents as well. Don't forget that you don't want rechargeable batteries to be over-discharged, or their lifespan will be shortened, so use that voltage droop as an indicator.

[maladroit]

That's why I like using the USB battery packs for 5V stuff. It's a lithium-polymer high capacity pack with a built in charger and built in DC-DC converter. Some of them even have solar cells that actually charge it at a somewhat usable rate.

[Shaolinskunk]

Jungle smacks do you mind sharing how you split yours into channels? Did you use a controller or make one yourself? Also where do you guys prefer to buy your LED's? I've always used superbright or oznium but if you have a better suggestion please let me know-

[junglesmacks]

I used a DIY controller from PIC Projects. Google it and you'll find his site. The controller is awesome and only like $40, runs up to 4A per channel I believe and is fun to assemble. Works with 12v fine and those strips would work with it. For LEDs, I use eBay sellers.

[AdamOfTheRedEarth]

Jungle smacks do you mind sharing how you split yours into channels? Did you use a controller or make one yourself? Also where do you guys prefer to buy your LED's? I've always used superbright or oznium but if you have a better suggestion please let me know-

I've been getting mine from ebay. Got to have lots of patience to look around for the deals and then wait for slow shipping on a lot of them that come direct from china but you can save lots of money.

[Shaolinskunk]

I used a DIY controller from PIC Projects. Google it and you'll find his site. The controller is awesome and only like $40, runs up to 4A per channel I believe and is fun to assemble. Works with 12v fine and those strips would work with it. For LEDs, I use eBay sellers.

found it! thanks.... (ill check ebay)

[bobsicle]

Most of the eBay sellers are buying direct from China via Alibaba or Aliexpress.

I have had good luck with Aliexpress for our mutant vehicle RGB led pixels... they require a controller for awesomeness and there are many to choose from.

For something simple and wearable, the basic controller from Cool Neon in Oakland is $20... they resell the RGB pixel strings under the name "total control lighting" and are nice people.

most of the medium range controllers can run your custom routines from an SD card. most of the software for creating sequences sucks.

a lot of great DIY stuff comes out of the very odd Christmas Lights subculture. Most of those people are very nice too and have been helpful with projects in the past.

[Foxfur]

I'll second the IKEA batteries. $3 for 10. I can't tell the difference between them and coppertops.