Need an Assist on Power Calculations

A place to discuss all things involving power and technology (including cameras). Generator tips, alternative energy, lighting your camp/bike/art/self, sound systems and more.
mitchfin
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Need an Assist on Power Calculations

Postby mitchfin » Thu Aug 03, 2017 9:09 pm

Hi, I am doing an art installation at our theme camp and have been reading so many different resources about power that they have started to blur together and now my brain is mush. So I thought better asking everyone than assuming I have the numbers right. I am somewhat new to dealing with electricity but feel like I have a solid base line knowledge of it all.

I am trying to order a battery and some solar for our camp (we are bad at attending the generator and don't want to run it at night). My real question is what size battery(s) do I need?

I am basically only running 35 meters of 9 watt/m (5v) LED strips, and then 25 meters of 18 watt/m (5v) strip, and a couple of arduino's.

I would only be running off the battery at night for max 7 hours. I am looking at a 12v 255 Ah battery (maybe 2) but when I do the numbers myself, put it into any eplaya/googled power calculator, or read posts about similar peoples situations I always come to a different number or conclusion.

So how much battery power do I need for my installation? Thank you in advance

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Token
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Re: Need an Assist on Power Calculations

Postby Token » Thu Aug 03, 2017 10:14 pm

You load is 765W. Let's call it 800W for some headroom.

800W / 12V = 66A of current being drawn from the battery.

With your 255Ah battery, you will reach 50% discharge in a bit less than 2 hours.

So you probably need 4 of those big boys to last 7 hours and not damage the batteries.

Charging will require 800W worth of panels. You could use less but then you gotta move the panels to track the sun a bit.

At the end of the day it will be cheaper and easier to run a Honda EU 2000 with a marine outboard gas tank. Not to mention weight and size compared to all that lead and panels.

Now if your led lights have a maximum rating of 9w/m or 18w/m when all LEDs are lit 100% duty cycle ... and you are sequencing them at 10% duty cycle ... well ... it can be less and more complicated.

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Admiral Fukkit
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Re: Need an Assist on Power Calculations

Postby Admiral Fukkit » Thu Aug 03, 2017 10:41 pm

"We are bad at attending the generator"
How about you get better at it? It's not like it's difficult.

Peoole don't realize how poor battery and solar efficiency and effectiveness is for handling anything but tiny electrical loads.

The battery/solar plan can be done but it's gonna be really expensive, really heavy, and more complicated rather than less. Knock yourself out.

badscr
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Re: Need an Assist on Power Calculations

Postby badscr » Fri Aug 04, 2017 5:56 am

Are the leds RGB addressable?

Can you link to the LED strips please. (For full specs)

Wireing diagram or discrimination

How are arduino being used, I assume controlling leds

Like Token was hinting to, with the duty cycle. Multiplexing the strips would lower the power requirements. Possible side effect could be a little less bright maybe not that human noticeable. Need more info, but could be firmware based.

Basicly turn on part of the leds for a few milliseconds then another part, so that at any given time only like 1/10 the leds are turned On this would lower the power to 100 watts. Need more info though.


Admiral Fukkit : I agree

If you do go solar, afterwards you can order a grid-tie inventor and put that 800 watts of solar to work paying for its self at 7 cents per hour of good sun.

mitchfin
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Re: Need an Assist on Power Calculations

Postby mitchfin » Fri Aug 04, 2017 4:27 pm

badscr wrote:Are the leds RGB addressable?

Can you link to the LED strips please. (For full specs)

Wireing diagram or discrimination

How are arduino being used, I assume controlling leds

Like Token was hinting to, with the duty cycle. Multiplexing the strips would lower the power requirements. Possible side effect could be a little less bright maybe not that human noticeable. Need more info, but could be firmware based.

Basicly turn on part of the leds for a few milliseconds then another part, so that at any given time only like 1/10 the leds are turned On this would lower the power to 100 watts. Need more info though.


Admiral Fukkit : I agree

If you do go solar, afterwards you can order a grid-tie inventor and put that 800 watts of solar to work paying for its self at 7 cents per hour of good sun.


I should say, the rest of the camp doesn't know how to work the generator (I know its super easy, but some people aren't all there) and when I'm gone people will try and mess with it and have broken rip cords in the past. But also I would ultimately love to not have to run it at night.

Here is the link https://www.aliexpress.com/item/1m-4m-5m-WS2812B-Smart-led-pixel-strip-Black-White-PCB-30-60-144-leds-m/2036819167.html?spm=2114.search0104.3.1.UyOhgX&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10068_10130_10084_10083_10080_10082_10081_5360014_10110_10178_10136_10137_10111_10060_10112_10113_10155_10114_10154_10056_10055_10054_10182_10059_100031_10099_9912_10078_10079_10103_10073_10102_10189_10052_10053_10142_10107_10050_10051-9912,searchweb201603_1,ppcSwitch_5&btsid=721cfb1b-de7e-4d2e-82a0-02c7b8ff7b51&algo_expid=94ed7d46-fd0f-4991-9e78-7c4c28f4cb52-0&algo_pvid=94ed7d46-fd0f-4991-9e78-7c4c28f4cb52, to the LEDs.

I would be wiring the 30/m between 2 8 foot pillars (about 3.5 rolls of LED each), each with its own 5V 10A power, probably at each end, I haven't wired the whole thing yet so don't know if I will need both. Then all 5 rolls of the 60 will be used in our camp with just 2 5V 10A boxes.

The Arduino's will be used as controllers for the LEDs.

Thanks again, I don't know many burners in my immediate circle that are literate with this so you've all already been a huge help!

badscr
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Re: Need an Assist on Power Calculations

Postby badscr » Fri Aug 04, 2017 7:39 pm

Use for practical lighting, or visually pleasing ( look pretty)?

How far in programming are you?
Need to get them wired on the floor and get that programming started. What's done in program can save a lot of power like Token said.

Once all wired on floor, hook an Ac amp meter to where you plug into your wall. This will give you a good idea of power draw.
Note I'm assuming you going, Battery to inverter then a 120vac to 5vdc power supply. Try to run power the furthist you can on the 120vac side.


Just avoiding white will save you 30% power. 100% of any two colors and 0% of the third, (red, green, blue)
A runner/chaser of say 10 leds of white would still be ok.



This two below is with all leds being lite, the fewer leds on the brighter the rest can be.

First in programming I'd limit max brightness to 20% (1/5) for all three colors witch would be 60% divided between them.
Example: 50% green, 9% blue, 1% red
Example 20% 20% 20% would be ok white
Or
This could be same as above or it may appear brighter depending on frequency.
I'd try the above first, if your happy with it then yay ,don't bother with the bellow method.
If you can get it so that only 1/5 of the leds are on at any given time that would get you to atless 5 hours (that's with all white all time).



You will lose 10% with inverter and then 10% of that on the Ac to dc. I Calculated it on 20% as I follow at less 80/20 rule

I don't have experience in large number of addressable leds only small numbers of 24.

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BBadger
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Re: Need an Assist on Power Calculations

Postby BBadger » Fri Aug 04, 2017 10:48 pm

You should get a generator. Each one of those 255AH batteries costs about $650 and weighs 150 pounds. You'll need at least four (4) of them, which is $2,600 + transportation.

Then you'll need to transport 600 pounds of batteries and 800W of solar panels (another $1000?), inverters and charge controllers ($500?). Once there you unload them, hook them up and hope you do that right so you don't fry your rig. Then run all the wires for those to your strips. After that, you need to monitor your array so you don't damage your batteries.

If you're doing this for this Burning Man, all this needs to be arranged in three (3) weeks.

You should go with a generator. A Honda EU2000i is $1000. A Honda EU3000is is $2400 -- less than your battery array. Either will probably last all night and more for your average load, meaning that you can turn it on and let it go. You can let the generator run out of gas and turn off on its own. The 3000 even has an electric start for your not-so-light-touch buddies and is quieter than the already quiet EU2000i.

Don't trust your addle-brained camp mates? Tell them to help carry the gas and fill it up. Then you turn it on: turn the switch to ON, flip the choke, pull the cord, and flip back the choke, walk away. Or teach them to not break the genny. Better than managing $2600 of 600 pounds of batteries, positioning $1000 worth of solar panels throughout the day, and still having to be around to shut down the array after 7 hours before the batteries get damage.

With the average patterns of addressable LEDs, you probably won't even use up the whole tank of a EU2000i (TWO thousand) each night at 400W; the EU3000is (THREE thousand) will definitely last all night. I've done this with over 2400 LEDs and have always had extra gas to spare when I shut down in the morning. You have more LEDs, but I'd still expect it to last 7 hours or more.

You have three (3) weeks. Using a simple generator will give you a lot more time than dry running some large solar array system and arranging the transport for all that gear.

You haven't even bought your LEDs or their supplies. You'll probably need to do some extra wiring with your LEDs to ensure that they have adequate voltage across the whole line so they look consistent, and be busy modifying and connecting your strips and getting your patterns to work.
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Admiral Fukkit
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Re: Need an Assist on Power Calculations

Postby Admiral Fukkit » Sat Aug 05, 2017 4:31 am

I run a hose from a 50-gallon truck tank to my pair of Honda generators and run power all week and never refuel.
You can buy premade 6-gallon external tank setups that will run it for a really long time.
I think you can't buy them in California... if you live there just piece it together yourself.
The tank itself is just an outboard boat motor tank, available at WalMart or a marine supply place.
If you get a quiet Honda, Yamaha, or even one of those knock-offs made of Chinesium (which I do NOT recommend, they don't make the same power even though the stated specs are the same, reliability is never as good, and parts availability isn't as good) it will run all night and no one will notice. The things are always running all over BRC.

Solar just for Burning Man doesn't really work unless you're into it as a hobby, or your power needs are very small.

There's a reason Hushville is so dark and no one has A/C! Miserable place let me tell ya.
Anyone looking for 100% silence has come to the wrong event.

badscr
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Re: Need an Assist on Power Calculations

Postby badscr » Sat Aug 05, 2017 5:52 am

I agree with Coyote, Admiral and BBadger.
A gen will simplify it and give more power during day time too. It's so close to the burn + ride time, there's not much time left tobe ordering, building, testing, debugging, modification, and optimizing for battery operation.

Could put (add/ fasten) a lockout door over the control panel and the pullstart handle.
So only someone with a key/code could touch the important parts.

My yellow Champagne came with a wireless keychain remote, just one quick push of a button and it would start on its own.
Maybe tie it to the gen handle.


Pull start broke (confirm by breaker) or was cut? I pull start quite violently and never broke one.
If someone did pull so hard to break it, I sore don't trust to operate a electric start.
Last edited by badscr on Sat Aug 05, 2017 5:59 am, edited 3 times in total.

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GreyCoyote
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Re: Need an Assist on Power Calculations

Postby GreyCoyote » Sat Aug 05, 2017 5:56 am

For what its worth, an EU2000 running synthetic oil loaded to 300 watts in eco mode wont even come off idle. That gives you 9-10 hours easily on one gallon of fuel. Maybe even a bit more.

If you go this route, elevate the genny a few inches to get its feet out of the dust. An inverted milk crate works great and you can store a spare 1-gallon tote under it without having to worry about it wandering off or becoming a football.
"To sum up my compassion level, I think we should feed the unwanted animals to the homeless. Or visa versa. Too much attention and money is spent on both."
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mitchfin
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Re: Need an Assist on Power Calculations

Postby mitchfin » Sat Aug 05, 2017 8:54 am

BBadger wrote:You should get a generator. Each one of those 255AH batteries costs about $650 and weighs 150 pounds. You'll need at least four (4) of them, which is $2,600 + transportation.

Then you'll need to transport 600 pounds of batteries and 800W of solar panels (another $1000?), inverters and charge controllers ($500?). Once there you unload them, hook them up and hope you do that right so you don't fry your rig. Then run all the wires for those to your strips. After that, you need to monitor your array so you don't damage your batteries.

If you're doing this for this Burning Man, all this needs to be arranged in three (3) weeks.

You should go with a generator. A Honda EU2000i is $1000. A Honda EU3000is is $2400 -- less than your battery array. Either will probably last all night and more for your average load, meaning that you can turn it on and let it go. You can let the generator run out of gas and turn off on its own. The 3000 even has an electric start for your not-so-light-touch buddies and is quieter than the already quiet EU2000i.

Don't trust your addle-brained camp mates? Tell them to help carry the gas and fill it up. Then you turn it on: turn the switch to ON, flip the choke, pull the cord, and flip back the choke, walk away. Or teach them to not break the genny. Better than managing $2600 of 600 pounds of batteries, positioning $1000 worth of solar panels throughout the day, and still having to be around to shut down the array after 7 hours before the batteries get damage.

With the average patterns of addressable LEDs, you probably won't even use up the whole tank of a EU2000i (TWO thousand) each night at 400W; the EU3000is (THREE thousand) will definitely last all night. I've done this with over 2400 LEDs and have always had extra gas to spare when I shut down in the morning. You have more LEDs, but I'd still expect it to last 7 hours or more.

You have three (3) weeks. Using a simple generator will give you a lot more time than dry running some large solar array system and arranging the transport for all that gear.

You haven't even bought your LEDs or their supplies. You'll probably need to do some extra wiring with your LEDs to ensure that they have adequate voltage across the whole line so they look consistent, and be busy modifying and connecting your strips and getting your patterns to work.



Great advice everyone, I think then it just makes sense to use the genny, right now this is what we have used in past years GENNY, do you think it is sufficient for maximum quiet and efficiency to last the night?

Admiral Fukkit, I live in Utah so should be pretty easy to get a tank extension.

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GreyCoyote
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Re: Need an Assist on Power Calculations

Postby GreyCoyote » Sat Aug 05, 2017 1:03 pm

Mitchfin: you are going the right direction! :)

FYI: that Kipor is $1600 and is an inferior product when you consider for $300 more you can get a Honda EU3000. The Kipor has a ~200 hour design life and repair parts are problematic. The EU3000 has a design life of 2000+ hours and repair parts are as close as any Honda dealer.

You might also look at the Yamaha analog to the Honda. Its a fine machine and is certainly better than the Kipor, and comparably priced.
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