Battery advice for lighting our art car

[Chaotic_Weevil]

Hey folks. My wife and I are putting together our first art car and its coming together pretty well. We are using a golf cart for the frame and want to light it up (obviously). Here's a link of the guy we are building- https://www.facebook.com/ZuggyDustmuncher

We need to power the following- one 50' strand of led rope, one 12 foot strand of RGB led tape, one .1 amp gobo laser, one 60w speaker, 2 led light bulbs that connect into one plug.

Rather than put our hefty generator into the back of our cart, my friend has suggested getting a 12v car battery with two inverters- one for the speaker and the rest for the lights.

My question to the board is has anyone used a car battery to power their lights? Is this a good plan? I know very little of electricity except that it lives inside wires.

Thank you in advance to you electric wizards out there.

[BoyScoutGirl]

Sorry that I can't help with the advice re: electricity and lighting, but I just had to say that Zuggy is adorable. I envision him scooting across the playa, stalking sparkle ponies while emitting all sorts of funny noises, like growls and hiccups and hungry, monstrous mutterings.

[some seeing eye]

Search ePlaya for watts, solar, battery, charging and LED and read those threads to get rough idea about electricity.

Then look on each thing you are connecting and get 2 of 3 or 3 of 3 specs for watts, volts, amps plus whether it's AC or DC. It will be marked or be in the documentation for the product. No one here can help you without that information.

[Captain Goddammit]

I can tell you more later, I'm eating lunch and on my iPhone right now..
But first thing, get a pure sine wave inverter. The cheapo ones will make your LED rope lights flicker annoyingly and not reach full brightness. I just went through that with mine.

Do you have a way to charge your batteries? If you have a generator, ideally you'll want a really BIG, high current battery charger, a 10 or 20 amp unit will take all day.

[Jackass]

If you want to get a night license, buy way more lights than you can immediately afford and then double that number. With that many lights you'll need more heavy batteries, at which point you will be better off with a small genie.

Otherwise you'll probably need at least two 12V Deep Cycle batteries, or you can go big and use 6V golf cart batteries instead. The batteries will need a charge throughout the week as well. Just my .02

I believe someone on here said it best," When testing your MV lighting at home, if you're not worried about the strong possibility of the neighbors calling the cops then you need to at least double your lighting." Or something to that effect

[uncle sticky]

Just remember that when using an inverter, the power usage goes up by a factor of 10. So, a household 40 watt lightbulb that claims 1.5 amp hours (meaning, it uses 1.5 amp hours of your battery every hour) at 120 volts, will actually use up 10.5 amp hours every hour from a 12 volt battery. A good sized deep cycle battery will hold, in theory, 100 amp hours (it says what the capacity is on the battery), so that one bulb could drain your battery in a single night.

[Chaotic_Weevil]

So, just to clarify, I should use deep cycle batteries to charge my lights? And recharge them too? I'm a little golf cart and I seem to be well-under the 600w that some of these inverters seem to put out.

[percussivepaul]

I run my camp's lights off of deep cycle batteries every night. One modest power inverter should work fine for all of this but the battery will be drained in a few hours, most likely. You have to do some math here to figure it out. A deep cycle marine battery is generally rated at about 100 Amp-hours which is 1200 Watt-hours at 12V, but you can depend on only maybe half of that capacity. So you get 600 Watt-hours on one full charge to play with.

50' LED rope might be 10 to 20W, 12 foot strand of RGB tape is probably 5 to 10W, laser I don't know, speaker is 60W, LED light bulbs are probably 5 to 10W each... total load is probably 100W to 120W ish. I would guess 4 to 6 hours of battery with everything going, maybe more if you're lucky, and if you're not running the speakers all the time you will do a lot better. Still, you would probably want to recharge every day. Make sure you have a high-current charger so that it takes only a couple hours of generator time to refill the batteries.

You probably want to stay lit all night, so maybe use one big battery which powers everything, and then keep a smaller reserve battery and disconnect the speakers once the big one is empty.

I'm also wondering how this little golf cart is powered, if there is a possibility of running stuff from the cart's power system.

[Chaotic_Weevil]

[quote="percussivepaul"]I run my camp's lights off of deep cycle batteries every night. One modest power inverter should work fine for all of this but the battery will be drained in a few hours, most likely. You have to do some math here to figure it out. A deep cycle marine battery is generally rated at about 100 Amp-hours which is 1200 Watt-hours at 12V, but you can depend on only maybe half of that capacity. So you get 600 Watt-hours on one full charge to play with.

50' LED rope might be 10 to 20W, 12 foot strand of RGB tape is probably 5 to 10W, laser I don't know, speaker is 60W, LED light bulbs are probably 5 to 10W each... total load is probably 100W to 120W ish. I would guess 4 to 6 hours of battery with everything going, maybe more if you're lucky, and if you're not running the speakers all the time you will do a lot better. Still, you would probably want to recharge every day. Make sure you have a high-current charger so that it takes only a couple hours of generator time to refill the batteries.

You probably want to stay lit all night, so maybe use one big battery which powers everything, and then keep a smaller reserve battery and disconnect the speakers once the big one is empty.

I'm also wondering how this little golf cart is powered, if there is a possibility of running stuff from the cart's power system.[/quote]

When you say "high-current charger", you mean for the battery that powers the lights right? I have a 10amp 48v charger for my cart which means it'll take me 6-8 hours to recharge my cart. My cart runs off of 6 8v batteries and I get a lot of charge out of them.

[percussivepaul]

Yeah, if you get a beefy deep cycle battery get an appropriately beefy charger. I think ours is 40A (12V) and only takes a few hours. This is a detail that people overlook, not realizing that small chargers could take days to refill a big battery.

I don't have any experience with golf carts and have only used 12V batteries in the past, but... I see no reason you couldn't get a 48V inverter (if your golf cart runs at 48V) and power at least some of your shit with the golf cart's batteries. They would run down a lot faster, of course, so you'd have to be careful.

[Captain Goddammit]

OK listen up. I've done all this, many different ways.
First, don't use one of those super-cheap inverters. They put out "modified sine wave" AC power. It's a choppy, rough waveform that a lot of electric things don't work right on. You need a "pure sine wave" inverter. Those put out power that is the same as the power in your house. There's more to it than just volts and watts. AC power has a voltage, a frequency, and a waveform. The cheap shitty inverters don't get the waveform right and your LED lights will not be bright and they will have a flicker to them that's rather annoying.

I have measured LED rope light and it consumes just barely under one watt per foot, so you'll be at about 50 watts to power your 50 feet of it.

When you say "60 watt speaker", exactly what do you mean? Chances are good it doesn't really draw that much... what exactly is your sound system?
If your 0.1 amp laser is a 120-volt thing, that'll only be about 12 watts. The LED bulbs could be anything from a watt to 20 watts or so, you'll have to tell us what you have.

The 12 foot strand of RGB LED tape won't draw much at all... so I'd say percussivepaul is right, you're probably at about 100 - 120 watts total. That will draw about 10 amps from a 12-volt battery, so a 100 amp-hour battery (your average deep-cycle battery) should give you around 5 hours before running down to half capacity, which is as low as you should run it. However, most inverters have a low-battery-voltage shut-off that will shut you off when your battery voltage drops to about 10 1/2 volts or so - so you might not get as much running time as you theoretically should.

You will need a good powerful battery charger to recharge your battery every day, if you use it a bunch.

Costco has a pretty good deal on 115 amp-hour deep cycle or "marine" batteries, about $80 or so. I'm using two, I might go get two more.
The only way you're gonna know if your power setup is adequate is to test it pre-playa, which I strongly recommend you do! Turn everything on and physically see how long it plays. Then see how long it takes to recharge.

[uncle sticky]

Costco also has some 6 volt cart batteries, about $90 each, I think, but they claim to be 220 amp hours. So, running them in series, do I have 220 hours, or 440? I'm guessing somewhere in between.

[Captain Goddammit]

220 amp-hours at 6 volts is similar total power as 110 amp-hours at 12 volts.
In series you'd have 220 amp-hours at 12 volts. That's twice the total power as one of those batteries.

In series you double the voltage. In parallel you double the current.

[Just_Joe]

Costco also has some 6 volt cart batteries, about $90 each, I think, but they claim to be 220 amp hours. So, running them in series, do I have 220 hours, or 440? I'm guessing somewhere in between.

beat me to it...

Series ( + to + and - to -)will give you 12 volts w/220 amps.
Parallel (+ to - and - to +) will give you 6 volts w/440 amps.

If you're going to connect a pair of batteries in series (or parallel) add another $20-$30 for cables to your budget.

[FIGJAM]

Thats backwards!

[Captain Goddammit]

Thats backwards!

Yes it is!

+ to + and - to - is parallel.
+ to - and - to + is series!

Read this that I just posted, explaining this electric stuff in an analogy to bicycles http://eplaya.burningman.org/viewtopic. ... 78&t=65368

[Just_Joe]

Thats backwards!

So THAT'S why the lights in my rig are so bright

It's too late to edit the post.
Keep Burning Man potentially fatal.

[uncle sticky]

Right, so to get 12 volts (travel trailer, so yes, 12 it is!) I connect one battery to another via a cable from a positive on one to the negative on the other. The cables from the trailer go positive to positive on one battery, and negative to negative on the other battery. Right?

[Chaotic_Weevil]

Okay. I'm lost, but I understood Costco and getting marine batteries and getting a good inverter so that's probably going to work for me.

[FIGJAM]

Here ya go!

http://www.zbattery.com/Connecting-Batt ... r-Parallel