chuckles304 wrote:

Hey everybody, long time no post.

So here's the story: I am planning on building a small cabin in the not-too-distant future in a patch of woods I own. This cabin will feature insulation, nice flooring, a woodstove, etc. I also plan on setting up a small car battery/solar panel charger system to power a few light fixtures with DC bulbs.

My puzzler is this - let's say I wanted to have a small bookshelf system too. If I run my batteries through an inverter to create AC power will there be sufficient steady power to run a small integrated and two small speakers? All I'm looking for is FM radio since I have a good classical station in my area, no CD players or any additional stuff. I realize 3-4 batteries won't be enough to power towers but I'm hoping, if this is even possible, that you guys know of some decent equipment that's low wattage/efficient/etc. Room size will be 15' x 19'. Thanks for any input.

First of all, be sure that your inverter is a TRUE RMS inverter that puts out a true sine wave and can deliver 120 volts RMS at 10 amperes or more.

They are expensive, but they are what you MUST have to run audio equipment. The cheap ones put out a modified square wave that is not suitable for audio or video equipment; you will get terrible hum and distortion using one of those.

One I would recommend is the Tripp-Lite APS 1250 1250 watt 12VDC to 120VAC inverter that sells for around $500 at various retailers online.

For your battery pack, I suggest that you get ten of the very large 12 volt golf cart batteries that are used in the newer golf carts. These have a long life and are designed to be deep-discharged without damage, which is what you need. Find an auto electric company that sells high quality batteries, such as Interstate for example. They will probably cost around $200 each. Wire at least four of them in parallel with #4 or #2 battery cables.

You should be aware that to supply 10 amperes of 120 volt AC current, the batteries will need to supply around 150 amperes of DC current, so at least 10 very large 12 Volt batteries will be required; perhaps more.

You will need a solar panel array that that can deliver 14V at 50 amperes or more for this kind of setup.

[quote=commsysman][quote=chuckles304]Hey everybody, long time no post.

So here's the story: I am planning on building a small cabin in the not-too-distant future in a patch of woods I own. This cabin will feature insulation, nice flooring, a woodstove, etc. I also plan on setting up a small car battery/solar panel charger system to power a few light fixtures with DC bulbs.

CORRECTION; i should have said to wire all ten batteries in Parallel. The wires from the batteries to the inverter should be 00 gauge.

You should be aware that to supply 10 amperes of 120 volt AC current, the batteries will need to supply around 150 amperes of DC current, so at least 10 very large 12 Volt batteries will be required; perhaps more.

You will need a solar panel array that that can deliver 14V at 50 amperes or more for this kind of setup (1000 watts).

280 watt solar panels can be purchased for around $500 each. Four of these, wired in parallel, should be adequate.

[quote=commsysman][quote=commsysman][quote=chuckles304]Hey everybody, long time no post.

So here's the story: I am planning on building a small cabin in the not-too-distant future in a patch of woods I own. This cabin will feature insulation, nice flooring, a woodstove, etc. I also plan on setting up a small car battery/solar panel charger system to power a few light fixtures with DC bulbs.

Everything I said above assumes that you want to have 10 amperes AC available.

With a small integrated amp, like a NAD C316BEE, and a tuner, you should be able to get by nicely with a 4 or 5 ampere capability.

In that case, you can halve the solar panel and battery requirements.

chuckles304 wrote:

You're up to $4500 in batteries and panels! All to replace a battery powered radio...(!) Suddenly this is sounding like not such a brilliant idea.

I know what I would do.

I would spend $100 or so on a good-quality car radio and hook it up to some 4 ohm speakers.

chuckles304 wrote:

THAT sounds like a BRILLIANT idea! Any 4 ohm speaker suggestions?(And why do they have to be 4 ohm?)

Car radios are usually optimized for 3.2 ohm speakers; low voltage into low impedance to get adequate power.

There are lots of home stereo speakers that are 4 to 6 ohms, just do some research.

The Elac speakers are mostly in that range, I believe. Many speakers will say they are 8 ohms when they are really lower.

commsysman wrote:

chuckles304 wrote:

THAT sounds like a BRILLIANT idea! Any 4 ohm speaker suggestions?(And why do they have to be 4 ohm?)

Car radios are usually optimized for 3.2 ohm speakers; low voltage into low impedance to get adequate power.

There are lots of home stereo speakers that are 4 to 6 ohms, just do some research.

The Elac speakers are mostly in that range, I believe. Many speakers will say they are 8 ohms when they are really lower.

In addition to car audio stores, there are also 12V audio setups that are designed for RVs. Check Camping World.