power draw?

[willsnow]

I'm designing (with the help of Don Casey's Sailboat Maintenance book. Fantastic information!) my electrical system to replace the non-functioning factory system. It will be pretty bare-bones: most of my components are LED lights or cabin fans that have power draws of 0.2-0.4 A/hr. Now, the marine stereo I'm considering is rated, I believe, at 160w. 160w÷12v is 13.3 A/hr... but that's at full blast. Does anyone have a better idea of what an average stereo would draw at a normal volume? And I would only be playing through an iPod, so no spinning of CDs or tapes.
Thanks

 

[willsnow]

And its a 1989 Mac 26d

 

[Ron20324]

Now, the marine stereo I'm considering is rated, I believe, at 160w. 160w÷12v is 13.3 A/hr... but that's at full blast. Does anyone have a better idea of what an average stereo would draw at a normal volume? Thanks

There was in 2013 a thread on the stereo power darw. Do a search. Otherwise, why not just get a good battery-powered iPod dock?

 

[Stu Jackson]

1A TO 2A was the answer in that prior thread.

 

[Don S/V ILLusion]

Why guess? Do you know how to measure current?

 

[Stu Jackson]

Here's the link to the last discussion. Why reinvent the wheel? :dance:

http://forums.catalina.sailboatowners.com/showthread.php?p=993058&highlight=stereo

 

[Ralph Johnstone]

I Wired Mine .......................

..................... for 10 amps as shown in the brochure (125 W) and the next season installed a battery monitor. Found the draw to be around 1.5A. Bloody waste of a lot of #8 wire .

I don't see how these units could use 125 W unless feeding more woofers and tweeters than you could fit into your cabin.


http://forums.sbo.sailboatowners.com/showthread.php?p=993056&highlight=stereo

 

[fredr]

Stereo Watts are measured in RMS watts (root mean squared). So while it seems you could do the math the way you did, it does not indicate the amp draw on your system.

 

[navigator97]

The Stereo power ratings in Watts is usually Peak Power audio. The Peak current Squared times the Speaker resistance. That is very different from the DC Power draw from the 12Vdc power source.

 

[shemandr]

Audio advertising loves to gin up the watts to sell loud.
We're finding our smart phone radio more useful than our stereo system. And we can get those baseball games and football games that we are out of range or out of market for.

 

[Ron20324]

... for 10 amps as shown in the brochure .... Found the draw to be around 1.5A. Bloody waste of a lot of #8 wire ....

10 amps was probably the circuit breaker suggestion. There should be a smaller in-line fuse close to the radio- 2 amps?