Powering LED Tape

Joined
Sep 13, 2017
Location
Texarkana , TX
I am working on a project where we are using 12v LED tape to light some moving set pieces. I'm 90% sure I have everything figured out but the power. Getting power to them remotely without running a power cable is proving to be a challenge. We need something that is reasonably priced and rechargeable. Thought about car/motorcycle batteries but those tend to be pricey and don't recharge very fast. AA battery cells also came to mind but I don't know how long they would power LED tape. I'm sure someone out there has done something similar to this and can push me in the right direction. Thanks in advance!
 

sk8rsdad

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There's not much information there to work from. How much LED tape? What's the total load or anticipated load? How long does it need to run for? How long do you have between uses to recharge something? Is the noise or exhaust fumes from a generator going to be a problem? Does it need to be waterproof? What's the budget? (presumably small if a car battery is considered pricey)
 
Joined
Sep 13, 2017
Location
Texarkana , TX
There's not much information there to work from. How much LED tape? What's the total load or anticipated load? How long does it need to run for? How long do you have between uses to recharge something? Is the noise or exhaust fumes from a generator going to be a problem? Does it need to be waterproof? What's the budget? (presumably small if a car battery is considered pricey)
Each set unit will probably not have more than 15-20' of LED tape. I don't have all the numbers in front of me so I can't answer the load question. Show is only about an hour and half long but I assume it will only run about 15 minutes of that total in different chases and flashes. Most of the time we will have approx. 24 hours between charges but there are a couple of double show days. Depending on the answer we could buy enough power units to run everything for both performances in one day. These are set pieces on stage so no a generator won't work and unless the building springs a leak waterproof won't be an issue either. Don't have a set budget just trying to keep the cost down as much as possible.
 

StradivariusBone

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Aug 23, 2013
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Space Coast, FL
Amazon has a 20' roll of RGB tape and it claims a draw of 24W at 12VDC. Amazon also seems to have 12VDC rechargable Li-Ion power packs that range from 3000-11000 mAh. I'd think for 15 minutes of use you could get away with a 3k mAh pack. IDK if your controller also needs power in this situation to pick up the DMX or whatever. That's another consideration, but I'd check out rechargable battery packs since they'll have the charging circuitry built in and are pretty compact as is.
 
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DrewE

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Mar 18, 2019
Location
Vermont
It would be most helpful to measure or look up the power consumption of your LED tape. They do vary somewhat depending on how many LEDs per meter, etc.

One option might be a power drill battery system coupled to a DC-DC converter. Quick chargers and batteries are readily available. A 4 Ah 18V battery pack (or 20V, which is exactly the same thing after the marketing department gets through with it) stores 72 Wh of energy. If required for the full hour and a half, that would mean a maximum of about 40W of LED tape after accounting for DC-DC converter losses etc., and I'd rather have less than that. Call it 3A at 12V maybe. Obviously shorter duty cycles mean larger currents could be available, as would being able to change the batteries.

DC-DC converter modules are available in various sizes and capabilities from many places, including Amazon. Oversizing them is not a bad idea, particularly for cheap import units of unknown provenance, as some are rather optimistically specified. Doing some good testing before the show is of course also a very good idea, and it would not hurt to have a spare or two available.

A simpler pre-built variant is one of the inverters powered by tool batteries that are available. Ryobi has a neat looking pure sine wave inverter unit for their 40V battery system available from Home Depot that I think is particularly attractive, as it's not unreasonably priced and being pure sine wave output there are no worries about powering most anything within its power rating. Many inverters are "modified sine wave" which really means a sort of bipolar square wave output that can cause electrical/RF noise and that doesn't work (well) for a few devices.

Car batteries aren't super pricey, in my opinion, but they are heavy and battery acid can cause all sorts of difficulties and poses some safety hazards on its own. Most car batteries are not at all designed for deep discharge, either; a trolling motor battery is somewhat better for that sort of usage (and a golf cart battery setup even better, though less convenient since you'd need two of the common GC2 golf cart batteries to get 12V...and that gets pretty heavy and large).
 

JChenault

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Joined
Jan 5, 2009
Location
seattle, wa USA
When we did chitty chitty a few years ago, we used about 40 to 50 feet of tape powered by a car battery. It was on for 5 minutes or so. We went a week without needing to recharge the battery. The failure mode was that things were not quite as bright.
 

Crisp image

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Jun 18, 2017
Location
Eastern Victoria Australia
OK we just finished Aladdin and I had about 4m (15ft) of RGB LED strip light in my set bits that were battery powered. I used 4s Lipo batteries (16.8V when fully charged) and for a double day show they used about 3500mA shows were only 1 hr long and had DMX Rx units on them too.
For our large set bit I had 12 strings of various lengths and used a deep cycle 12v battery. I had some other lights in another bit that was also on 12v battery.
Have a look around and you may find some 2nd hand batteries that will not start cars but will be able to hold enough capacity to do what you need. With an over night charge in between to keep them topped up. Go the the local wreckers and ask.
I like the lipo because they will charge in about 45min depending on capacity used and they are smaller than other batteries with a good output.
I will log in on my phone and put up a couple of photos of the set bits I mentioned above.

Regards
Geoff
 

NateTheRiddler

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Dec 27, 2018
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Arizona, US
Just keep your hands off my Tesla
To be fair, if anyone goes to the massive effort of dissecting your Tesla just to obtain some battery power, don’t you think they’ve kind of earned it at that point? XD
 

GhostLighter

Member
Joined
Apr 13, 2013
Location
Arlington, VA
I may be bumping a semi-dead thread here, but I would be remiss if I didn't mention 18650 batteries. Small and powerful (for their size). They're my go-to battery if I need to power LED tape/flicker candles/12V bulbs (via a RC4 dimmer) in a small package. 3.7V, and I use the 3500 mAh/30A continuous variety.
 

theatrewireless

Jim @RC4Wireless #RC4DoesThat
Joined
Aug 21, 2009
Location
Raleigh, NC
Lots of great info in this thread!

I’ll add that well designed LED drivers, including wireless ones like we make at RC4, don’t draw much power, but they do draw power all the time, which is often the entire length of the show. In most cases the load from the LEDs, motors, or lamps far surpasses the draw of the receiver and driver electronics, even when you consider that they are probably only operating for a few minutes. Thus — in most but not all cases — you can safely do the math with just the broad strokes of load current and battery A/h rating.

All batteries become less efficient when the current draw is higher, so the number printed on the battery is probably not what you’re going to get. For example, a 20A/h battery is often rated with a test that draws 1A for 20 hours; if you put a 20A load on that same battery it will last only 30 minutes. Always add extra margin; if you have the space and can afford it, use a battery rated for double what the math says you’ll need.

Jim
RC4 Wireless
 

ship

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Mar 29, 2003
Location
Illinois
I powerered up a Trident for "Little Murmaid" with probably more RGB high output tape inside it by way of a Milwaukee M2 12v Lithium battery. (Probably a post on this for research.) Overall time in use was about similar. Don't remember how I connected the battery in powering the trident up - been a few years, but was easy enough to charge and sufficient power. Simple and overall cheap as the Dad needing the trident for his son's show needed a new cordless screwdriver anyway.