# question about battery powering an instrument

#### organ grinder

Joined Feb 4, 2014
15
hello!

i'm an instrument maker. mostly not electrified instruments but I have decided to "plant" a bunch of reed organs I found that were discarded after Katrina hit New Orleans.

it would be nice for passers by to wander upon something like this and have some musical fun.

they are all reed organs which is basically a fan pushing air across reeds that open when a key on the keyboard is depressed.

I have been told to go for a marine battery because they are a safer gel substance and charge and discharge more thoroughly with more longevity.

I have also been told to avoid modified sine wave invertors for direct to amps BC of noisiness. This is, however, just an electric fan really so I cant expect that would be a problem.

here's where I'm over my head.

I need to figure out what size battery to get, what size wiring is appropriate and a suggestion or two on what kind of inverter.

I want to run

Deep cycle marine battery---inverter---on/off/timer switch---fanmotor

I believe that is the correct thing to do.

the organ power information is:
115-120V
60 CYC A.C.
42W
.375A

if someone can hook me up with the right information and an understanding of this, I would be more than willing to pay.

#### R!f@@

Joined Apr 2, 2009
9,750
How do you intend to charge the battery?

Do you have a computer UPS laying around by any chance

#### MrChips

Joined Oct 2, 2009
24,170
So far you have the right idea.
So a battery with 100AH rating should run the organ for about 25 hours.

#### organ grinder

Joined Feb 4, 2014
15
a few of the boat places here do marine battery charging, I figure I would keep about 5 on hand in storage, ready to switch out.

the organs are remade in bargeboard and waterproof. I plan on placing absorption devices inside to reduce the humidity in the chamber. I have approval to bolt one so far, to a non-utility pole.

I'm not sure about certain possible pitfalls such as, will the battery/inverter create a heat issue? the fan only gets minorly warm.

I'm looking at a sauna timer that you turn the knob and it goes from 0-10min. then, if you wanted to keep playing, you'd have to turn the knob again, that way it wouldnt just suck power all day long.

im worried about the size of the chamber and if I would need to make a separate chamber or if I can find a marine battery for what is basically a shoebox size area.

#### organ grinder

Joined Feb 4, 2014
15
i've never bought an inverter before, so I'm not certain about inverter pitfalls, or in pure EE sense, what tells me what guage of wire to run between these things to make sure it doesnt starve or overheat.

i actually leaned that from Harbor Freight, who sell OK tools but they usually have tiny cords and cheap plugs that starve those tools to death, so much so, that whenever I buy a tool there, I immediately replace the cord and plug with a heavier cord and plug buy just 1 guage difference and it makes all the difference in the world!

#### organ grinder

Joined Feb 4, 2014
15
i need to form this into actual coherent questions. i'm going to go finish building my fence and come back in a bit. any and all information is appreciated!

#### #12

Joined Nov 30, 2010
18,223
It's about impossible to buy a cord that won't handle 4 amps, unless you're talking about more than 50 feet. I calculate about 18 AWG wire, minimum and I don't think you can buy a cord smaller than 18 gauge.

#### MrChips

Joined Oct 2, 2009
24,170
I think you'll be ok. Your organ only draws 42W. Inverters can begin at 100W-3000W.
A small 100W inverter should work ok.
The wire from the battery to the inverter needs to carry 4A.
From the inverter to the motor is about .4A
Ordinary lamp cord will work in both cases.

#### R!f@@

Joined Apr 2, 2009
9,750
Battery to inverter cable should be thick though.
It will reduce cable loss dramatically.

#### GopherT

Joined Nov 23, 2012
8,012
If all you are powering is a fan, why don't you change the 12v AC fan to a nice 12 volt DC motor (fan). The market is full of modern, high efficiency cooling DC fan motors from all types of electronic equipment are available.

If I were you, I would modify to make it simpler rather than add a level of complexity.

#### #12

Joined Nov 30, 2010
18,223
Good point. Every dead computer has a 12 VDC fan in it. Maybe 2 if you look inside the power supply.

#### organ grinder

Joined Feb 4, 2014
15
i thought about something like this:

http://www.ebay.com/itm/3-X-5200MAH...Control_Parts_Accessories&hash=item1c3c3d2c3d

but from my RC days, I seem to remember that these kinds of batteries leak their charge away at a pretty bad rate. right now I am looking to find this battery option and avoid making a battery case/changing the aesthetic, but the chamber ( a 4.5" tall x 7.5" long x 8" area) is proving to be a challenge!

#### organ grinder

Joined Feb 4, 2014
15
woah. didnt even think of DC fan..

#### organ grinder

Joined Feb 4, 2014
15

#### GopherT

Joined Nov 23, 2012
8,012
Let us know where you mount this thing. Would like to visit. I'm in Baton Rouge and New Orleans about every 6 weeks.

#### organ grinder

Joined Feb 4, 2014
15
i'm geting approval for state st off of st. charles where it was thrown out, uptown. makes me think it was water from roof damage as there wasn't much street or flood water there from Katrina. I want it to reappear in its place, renewed, and as some might know, the schools here dont care for the art or music they promote. We're trying to stop them from passing a draconian music ordinance presently. As a teacher, I've literally had a student tell me, "I've got a gun and a trumpet and I canmake money with both." why would you prevent someone from making the good choice there? yet somehow, city hall still harasses musicians like always.

I'm bench testing the components together before they go in and I am trying to see if the inverter will suck energy from the battery and steal its life and whether I can somehow tie the timer switch into one of the battery to inverter leads, to keep the inverter from vampiring the power out of the battery.

trying to scrape the money together to get a video made when its installed, to put on the net to tell the city its there. got some friends who can play!

the tone on this thing is totally Shot in the Dark by Mancini (which I knew from the old inspector Clouseau pink panther cartoons), so thats the song we're gonna play.