[jdimitri]

Hey all..

I've just started busking and really enjoying it
It's fun to play, i occasionally meet interesting people and the money isn't too bad either

One thing though.. i want to use my AER acoustic amp (40w) instead of my crappy battery powered roland amp/pa thing (costed me a hefty $450 too.. gotta get that to ebay soon)

How do i do this? I know i should get a battery and an inverter but that's about all i know

How big of a battery should i get? How do i charge it? Etc..

Any help would be much appreciated

I searched the good ol google but it mostly contains info about how to power up caravans

 

[NeObliviscaris]

i cant help, but where do you busk?

 

[KYTGuy]

40w is a pretty easy load to run from a 12V batt. Here in the U.S., we have many sources for the Inverter. One of the best IMHO, is the "Power Pack" unit - incorporates a Gel Cell (No acid spills) and an inverter, often with a Light, and maybe a tire compressor, along with a pair of jump cables. Usually the Inverter is a small one, usually under 100 watts - this would be perfect for your use. The Light could be used as part of your act, and to hook up your setup in the darkness. Ofcourse, the unit would be good to jump your car if it needed help also. It could be recharged by your car while driving to the event, or by a cheap motorcycle 1 amp charger you can get from an auto supply house for around $10.00 USD. These "Power packs" are usually around $50-$100 USD, depending on the size of the battery, and the other features included.

You need to figure out how long you will be Busking, then take the figure 80 (twice your load wattage) and multiply by the hours you figure you will go at one time. That will give you the watt-hours you need. That, divided by 13.6 (nominal battery voltage) will give you a rough Amp-Hour requirement. Find a "Power Pack" with the required amp-hour rating, and you are set.

Keep in mind though, that Lead-acid batteries don't like to be deep discharged, and that they last longer when they are immediately recharged.

You lucky Dog, You live in AWEstralia - it has been years since I've been there.

 

[jdimitri]

Quote:

Originally Posted by FeedMeTrance /img/forum/go_quote.gif i cant help, but where do you busk?

In the city.. usually around flinders

Thanks KYTGuy.. I assume you're talking about one of these?

HAIGH Australia PTY LTD

Tell me if my calculations are right.. 80x 4 = 320

320: 13.6= 23.52..

Does the fact that we're running 220-240v matter at all?

But aren't car batteries not meant to be drained completely?

And how would i go with a more traditional approach (car battery -> inverter)

 

[KYTGuy]

None of the models listed on your lingk had an inverter within - thw ones here in the U.S. sometimes do, so you would still need an inverter.

The reason I said the Power packs are good is that they are enclosed, and don't leak. I have ruined many good clothes bedcause of an acid leak. Acid can leak, evaporate nearly to invisible, and they actually get more powerful. If you have a battery of any size, and it is of the conventional and cheap design, you have threats of acid spills, and someone dorpping a cable or item they are wearing/carrying that can cause the battery to catch fire or explode.

Yes, it is really bad to take the cheap car batteries and discharge them much past 25% down. If you discharge them past 50% and leave them in that state overnight, you have just converted the battery capacity to about 85% of what it was before. This change is Irreversable, and if you took a perfect, new battery, discharged it till flat, left it a week, and then tried to use it after a recharge, you would be lucky to have a 25% capability from new.

Now, back to the Inverter - some amps are sensitive to the waveform provided - most cheap inverters make nearly square wave power, nominally @ 60Hz here, I forget if you use 50Hz there. You should listen to your amp on whatever inverter you buy before you put down your money. You may have to pay more for a better waveform inverter. True Sine Wave inverters get $pendy.

Back to the calculations - that shows the minimum battery that will do what you need, but you should get the biggest battery you can transport and afford. That is so that you don't dip too far into the battery's rating before the next recharge. If your needs are met with 20% of the batteries capabilities, that would be about Ideal for the battery, but it might not be good for your back.

I would urge you to case the battery to prevent most chances of spills, and to prevent shorts across the terminals. You could mount the inverter to the lid of the battery case. Inverters need good airflow.

Brings to mind another part of the calculation - the efficiency of the Inverter. If ti is not pretty efficient, you will need a bigger battery and inverter to handle the load. I added 100% to the needs (doubling the wattage of the amp) to the calcs I had you do, but if the inverter is not pretty efficient, you will need more.

You might be needing a fork truck!!

 

[siconnelly]