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I just bought a simple Casio keyboard Privia PX-330 and Roland KC-150 amp. I need to use both for an outdoor gig, but the location will NOT have power.

I'm looking for a recommendation on a generator which would be suitable to power a Keyboard and Amp which is ultra quiet, for the obvious reason that I do not want generator noise to overpower the music.

I do not need the generator for other purposes (like powering an RV, campsite, my house, etc.). So I do not need "extra" power. Just the minimum to work my keyboard.

The keyboard's power supply says 1.5amps / 12 volts, so I calculate that to be 18 watts. The Roland says it's rated to draw 55 watts. So the total wattage draw is pretty LOW.

Anyone have experience with a generator or battery power system which might work well? The system would need to provide continous power for at least 2 hours.

Thanks!
-Earl

There's a chap on youtube using a Privia out and about, maybe its possible to work out what he uses.
http://www.youtube.com/watch?v=wxzkPoVX5YI

What will be your energy source?

If you have a nearby car/truck, you can use its battery directly to provide 12 volts. You could plug into the car's cigar lighter or accessory jack. (Cheap.)

Or you can get a power inverter that converts the car's 12 VDC to 120 VAC. Power the keyboard from that. (Not as cheap.)

Searching Google for "car power inverter" ... here are several of the latter for $25 to $35 ...
Peak
Die-Hard
Duracell
XOvision
Whistler

+1 for MacMacMac's answer, its what I was going to suggest.

You could also use a motorcycle or boat 12v battery. Or you cold also use 1 or 2 12volt alarm system batteries in parallel.

Make sure you install a fuse at the battery end though! if there is a short circuit on the line or a failure in the keyboard, it will all go up in smoke very quickly because a car battery can deliver a lot of amperage!

If your power source like a car is far away (more than 25 feet), use heavy gauge wire to run from the power source to the keyboard. Why? Resistance! a long wire acts like a resistor and the longer it is, the more resistance, the less voltage and amps (thus watts) at the other end. in a worse case, you would start out with 12 volts and by the time it reached the keyboard it would be down to 10 or 9. The keyboard might still run at this low voltage though!

Last thing: you'll likely need to find the exact coaxial plug to match the socket on the keyboard. A good electronics store would have it, otherwise you would need to chop off the one on your current power adapter. Be sure to observe the proper polarity when wiring the power source!!!

John

For all that trouble, it's probably cheaper and definitely easier to just buy the inverter. Plug, play, done.

(For those who have the skill and the parts, your advice is entirely valid.)

Yes, actually - the power inverter solution should work just fine for my needs. I'll give it a trial run before the actual event just to be sure.

Thanks for all the great ideas, everyone. Absolutely brilliant!

I wouldn't bother with the inverter. The inverter uses energy itself and I don't see the point in converting from 12VDC to 120VAC back to 12VDC. It wouldn't be hard to rig up something that's easy to attach to a car electrical system. You could probably even pay a local technician to custom make it for you for the price of an inverter.

I would definitely get a marine battery. Even if you replace your car battery with one. The reason is the marine battery is a "deep cycle" battery. It is made to provide power, then be recharged. A car battery isn't worth much in providing power. It is designed to provide a quick short burst of power. That's all.
Seems to me. Ideal? A marine battery you carry in the back. Use it with an inverter, if you need 120AC. You can use the car system to recharge the battery.

Just for info. The alternator on a car, generates 120AC. It has a "bridge" on the back which converts it to 12DC. Why? AC generators are much more efficient. Also physically smaller.

Also would have to consider how much power the inverter uses in converting.

No need for a marine battery. Yes, a car battery can provide hundreds of amps for that short, start up burst. But the piano needs less than 2 amps. The car battery can run for hours under those conditions. There's no need for a deep cycle battery.

Car generators do NOT generate 120 volts AC. They generate a bit more than 12 volts AC. That "converter" on the back is just a bridge rectifier. It converts the power to DC.

I hate to argue. I also hate to see people who don't know. End up finding out the hard way.
I have no argument that a typical car battery can deliver a couple amps for hours. But! You will ruin it quickly trying to do that. It won't do that many times. A car battery is closer to a capacitor than a battery. It just ain't designed to do that. You may even ruin it the first time you do that.
The guy could even just replace his car battery with a deep cycle battery. I would rather have a separate one.

The original poster indicated 55 watts for the amp. Then he is closer to pulling 6+ amps from the original DC supply with both the amp and keyboard. That doesn't include wasted power..ie...RVA. Also include further what the inverter actually wastes. Simply talking about an inverter suggests AC. Due to the higher current draw. I would much rather go with a larger deep cycle (marine) battery. They are built to do this and start a motor.
Otherwise....this guy is actually going to have a car supplying background noise the whole time he plays? In other words. Leave the car running? Would be better off with a small Honda generator. They are known for being quiet. Still I wouldn't tolerate any background noise.

On the alternator. I don't need to argue.

A battery can power and AC inverter but as a rule of thumb you need 10 DC amps and ever AC amp. So if your gear needs 2 amps at 120 volts the inverter will pull 20 amps from the battery. That is a moderate load. I just guessed at the 2 amp number. It mostly depends on your PA system as the piano draws nearly nothing. Just look at the back of the amp and there should be a placard. Or look at the fuse and figure it draws less then that.

20 amps times 2 hours is "40 amp hours". Pulling that from a standard car battery would kill it. Buy a deep discharge battery rated for at the very least twice the number of amp hours you need. place the inverter physically near the battery and run extension cord from inverter to your PA and piano.

If you must use a generator buy a Honda. It is the ONLY way to go and yes even the quiet running Honda makes nice so (no kidding) buy a 200 foot #10 extension cord (They sell these to construction workers, check the local lumber yards.) and place the Honda on the other side of a building FAR away from the event.

The deep cycle battery will cost between $100 and $200 and then another like amount for a good SINE WAVE" inverter. Yes, do get the sine wave type if powering audio gear. I thing the best deal in deep cycle batts are golf cart batteries. They are 6 volts so buy two. You wil need a box to put them in and a fuse inside the box.

You will also need a small battery charger to use between gigs and a hand truck to move all this gear. A 200 food #10 extension cord is maybe 50 or 60 pounds

For 2 amps at 120 volts (240 watts), that's true. He'd pull 20 amps from the battery ... plus a bit more since the inverter can't be 100% efficient.

But the OP doesn't need 2 amps at 120 volts.

He said the piano's supply is rated 18 watts max (1.5 A at 12 V). The piano probably uses a bit less than 18 watts.

The amp says 55 watts (around 0.5 A at 120 V).

So he'll only pull 73 watts total ... or around 0.6 A at 120 V from the inverter.

That translates to 6 amps from the car battery (plus a bit more for the inverter's losses).

That is a good point. A good inverter costs money.

Just food for thought. Instead of going through all this. You could just work with sound proofing a Honda generator. Build a three sided box with a top. Something good for killing sound on the inside surfaces. Something easy to throw together and take apart. Leave one side open because the generator must have air for cooling and breathing. Then also place the generator a good distance behind the stage. Bear in mind. We're talking about a generator that you can stand over it carrying on a conversation without raising your voice. 100 feet away with the sound box around it just might make it tolerable.

Just a crazy idea if you do end up using a generator and you can't get rid of the sound - try to exploit the sound as a bass drone in your songs, as much as possible. ;^)

Greg.
p.s I have a "silent" generator. A far more accurate word to describe it is "noisy".

I'll add my voice to the marine\deep discharge batteries as well.

Another thought... for the cost of a generator, one could buy a battery powered Yamaha or Casio keyboard and a battery powered Roland amp... possibly these can even be rented from a local music store...

Step 1. Find an amp tech, a local appliance repair store or an electrician.

Step 2. Tell him you want a battery pack for a keyboard for 4 hours of play. Bring the manual and the plug to him or her.

Step 3. Buy a battery powered amp, like the Roland KC-110.

Step 4. Profit. You've got everything you need for outdoor play. You can have everything held together by band-aids and bubblegum, but having simple, professional equipment will pay off in the long run.

On a side note, I have seen a battery powered amp with a 120V plug, but I wasn't able find it with google.

I reckon it is probably already possible to power the PX-330 from a 12V battery, because it runs off a 12V power pack. Regardless of how well regulated the power pack is, I'm betting that there would be another regulators inside the PX-330 to drop this down to 5V (or whatever they use these days) for the sensitive digital circuitry.

IF this is true, it'd be cool if Casio could come up with a way to allow battery power to be supported for warranty purposes.

Greg.

I have been looking to do the same thing for our Yamaha P-255. On the AC adapter it says input 45W and output 16V 2.4A We really want to play in places where there is no way to plug it into AC.
An electrical engineer friend of mine directed me to a Duracell Powerpack http://www.amazon.com/Duracell-600-Watt-Powerpack-Pro/dp/B009YR00MI
I am wondering if it would supply enough hours of Keyboard use. What do you people think?

That looks pretty cool. I have an older Duracell unit like that but it only gives 200W. I haven't used it to power a piano setup, but it still holds its charge well. They also have a 1,800W unit, although it weighs 58lbs.