Hello all. I am trying to calculate my projected power loads, but I am having a problem calculating how much the stereo will draw. Now, the West Marine Catalog says it will draw 200W Peak (50 X4), but I wouldn't think that the stereo would be wokring at 200W, in fact I'm guesing more like 30W ~ 50W. What would be a good ball park figure to use. The way it looks, with all nav lights and cabin lights, stereo and VHF I'm at about 176 Amp/Hr (Very Liberal with the estimating). Would this be a normal range value for a 25' sailboat in a 24Hour period?
Calculating stereo power load on 12V systems
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sounds like a lot to me!
At 175 amps per day you're gonna need at least a 350 to 400 amp house bank which I think would be a lot of batteries for a 25 foot boat. I'm sure somebody more knowledgeable about these things will pipe in somewhere.
At 175 amps per day you're gonna need at least a 350 to 400 amp house bank which I think would be a lot of batteries for a 25 foot boat. I'm sure somebody more knowledgeable about these things will pipe in somewhere.
Yup, that was a tad high
Ya, I agree my original estimate was...over zealus. I've recalculated to 76 Amp/H, not including the stereo of course.
Ya, I agree my original estimate was...over zealus. I've recalculated to 76 Amp/H, not including the stereo of course.
Okay, think I have it now
Okay, it would seem I was a bit high. The Amp/h for a 200W stereo is around 2 ~ 3 Amp/h Average. That is more like it. My actual draw will be more like 40 ~ 50 Amperes per day. That I can handle quite well, with my 160 AMP deep cycle.
Okay, it would seem I was a bit high. The Amp/h for a 200W stereo is around 2 ~ 3 Amp/h Average. That is more like it. My actual draw will be more like 40 ~ 50 Amperes per day. That I can handle quite well, with my 160 AMP deep cycle.
sound like permanant ear damage
to me! Most of us sail to get away from the noise. I think they should be outlawed along with the buzzing little targets (jet skis).
to me! Most of us sail to get away from the noise. I think they should be outlawed along with the buzzing little targets (jet skis).
200 watts...
50 watts per channel X 4 is OUTPUT at maximum, not a "draw". Amp/hrs to produce those watts is a whole 'nother deal. Somewhere in the specs. there should be information on how many amps the unit will draw while operating. Higher the volume however, the more amps it will draw.
50 watts per channel X 4 is OUTPUT at maximum, not a "draw". Amp/hrs to produce those watts is a whole 'nother deal. Somewhere in the specs. there should be information on how many amps the unit will draw while operating. Higher the volume however, the more amps it will draw.
stereo
Most often the stereo will have required amperage listed on it somewhere, many have a fuse on the rear, if they do I calculate based on the fuse rating. My sony has a 10 amp fuse in it, though I know for sure it doesn't draw 10a at all times, it does give me a good safety margin Also, the rating on a stereo (45wx4) is most often peak output, have determined that at 50wx4, it's actually 17wx4rms, the higher rms rating will allow much cleaner sound at low volume level, I have an old almost antique rockford fosgate 200w rms amp that will outperform 600w peak amps with ease, and I use it primarily because it does give very nice clean sound with zero fuzzout with bass, but I also know a lot of songs that just beg to be turned up a bit. I like music but I like it to be clear. also, on my amp, I my radio is an older sony cassette player, so instead of getting a CD deck, I feed the amp through the speaker leads, not the line in, I use the line ins for my mp3 player so I can use it in the truck. toggle on the amp remote lead lets me turn it on. ken.
Most often the stereo will have required amperage listed on it somewhere, many have a fuse on the rear, if they do I calculate based on the fuse rating. My sony has a 10 amp fuse in it, though I know for sure it doesn't draw 10a at all times, it does give me a good safety margin Also, the rating on a stereo (45wx4) is most often peak output, have determined that at 50wx4, it's actually 17wx4rms, the higher rms rating will allow much cleaner sound at low volume level, I have an old almost antique rockford fosgate 200w rms amp that will outperform 600w peak amps with ease, and I use it primarily because it does give very nice clean sound with zero fuzzout with bass, but I also know a lot of songs that just beg to be turned up a bit. I like music but I like it to be clear. also, on my amp, I my radio is an older sony cassette player, so instead of getting a CD deck, I feed the amp through the speaker leads, not the line in, I use the line ins for my mp3 player so I can use it in the truck. toggle on the amp remote lead lets me turn it on. ken.
Not volume that I am looking for
I mentioned it was 200W Peak and I gave that value to help determine what my load would be. I'm thinking a little backgorund music or news reports, not a bass blown full volume sound system. As for the comment about jet ski's, they don't bug me, the noise or the drivers.
I mentioned it was 200W Peak and I gave that value to help determine what my load would be. I'm thinking a little backgorund music or news reports, not a bass blown full volume sound system. As for the comment about jet ski's, they don't bug me, the noise or the drivers.
if you want a simple answer...
how long would you leave your car radio on before your car battery went dead? 4-5 hours? That about what you can do on your boat. Peak power is maximum audio noise with lots of distortion. The amplifier being over driven. RMS power is clean audio sound. The amplifier operating in a linear manner before it's over driven.
how long would you leave your car radio on before your car battery went dead? 4-5 hours? That about what you can do on your boat. Peak power is maximum audio noise with lots of distortion. The amplifier being over driven. RMS power is clean audio sound. The amplifier operating in a linear manner before it's over driven.
Lights are easy to figure
the power usage for. You could replace the incandescent lamps with leds and save a relatively huge amount of power use that way. My friend with the 46 foot Hardin puts up 4-5 strings of incandescent Christmas lights and has to run a 2000 watt generator to light them away from the dock. An equal number of LED lights will draw less than 50 watts by comparison and they never burn out. Another factor is that they do not break and leave glass on your deck. The radios will use very little power on receive especially if you can turn off the displays. Transmit is a lot more power use but for a very limited time. If a handheld VHF will suffice, that will use far less power than a built-in model. The stereo will use 3-5 watts of audio at normal "listening to the news" volume unless you have huge speakers or turn it up a lot. You can probably figure under 10 watts total on average unless you are being buzzed by jet-skiis and have to turn it up. The display will again likely be a significant draw if it stays lit all the time. You didn't say if your stereo is 12 volt or 110 volt. If it runs on AC, the inverter will increase the power required by another 50% or more depending on the unit.
the power usage for. You could replace the incandescent lamps with leds and save a relatively huge amount of power use that way. My friend with the 46 foot Hardin puts up 4-5 strings of incandescent Christmas lights and has to run a 2000 watt generator to light them away from the dock. An equal number of LED lights will draw less than 50 watts by comparison and they never burn out. Another factor is that they do not break and leave glass on your deck. The radios will use very little power on receive especially if you can turn off the displays. Transmit is a lot more power use but for a very limited time. If a handheld VHF will suffice, that will use far less power than a built-in model. The stereo will use 3-5 watts of audio at normal "listening to the news" volume unless you have huge speakers or turn it up a lot. You can probably figure under 10 watts total on average unless you are being buzzed by jet-skiis and have to turn it up. The display will again likely be a significant draw if it stays lit all the time. You didn't say if your stereo is 12 volt or 110 volt. If it runs on AC, the inverter will increase the power required by another 50% or more depending on the unit.
Excel Spreadsheet
I created an Excel spreadsheet that lists everything that uses power (cabin lights, water pump, radio, GPS, Nav lights, CD player, bilge pump, auto pilot, shower sump, etc.). I then entered how long each day/night that the item would be used and out pops how many Amp Hours are consumed. For my H28 on a day cruise I estimate 45 AHrs, for an overnight it is 85AHrs (mostly because of the lights). If you have an inverter or a refrigerator you will use LOTS more power.
I created an Excel spreadsheet that lists everything that uses power (cabin lights, water pump, radio, GPS, Nav lights, CD player, bilge pump, auto pilot, shower sump, etc.). I then entered how long each day/night that the item would be used and out pops how many Amp Hours are consumed. For my H28 on a day cruise I estimate 45 AHrs, for an overnight it is 85AHrs (mostly because of the lights). If you have an inverter or a refrigerator you will use LOTS more power.
Thanks Steve!
That is what I was looking for, average loads. I think my manual calculations are in the ball park. Can I ask what size of battery bank you are using? I am looking at a 160 Amp/Hr deep cycle, and then a starting battery 650 C.C. Amps. Each on its own circuit.
That is what I was looking for, average loads. I think my manual calculations are in the ball park. Can I ask what size of battery bank you are using? I am looking at a 160 Amp/Hr deep cycle, and then a starting battery 650 C.C. Amps. Each on its own circuit.
Keep In Mind
Remember most "deep cycle" marine batteries recommend recharging when the battery is 50% discharged. The 160 amp hours you have may not all be useable on a regular basis without long term damage to your battery. The West Marine catalog has a good write up on batteries and charging systems.
Remember most "deep cycle" marine batteries recommend recharging when the battery is 50% discharged. The 160 amp hours you have may not all be useable on a regular basis without long term damage to your battery. The West Marine catalog has a good write up on batteries and charging systems.
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