I have a 125W stereo running off a Xpower 150 power pack and it will play one CD and then run out of power. The specs for the Power pack are: -Runs 115-volt AC or 12-volt DC products anywhere -Built-in 150 watt inverter -Sealed, non-spillable 12 amp-hour AGM battery The specs for the stereo are: -Power Requirement AC120V -Power Consumption: 125W Can anyone tell me what is going on here or recommend another product?
Stereo Running Down Battery Too Fast
- Thread starter Cate
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Power requirements
If it was a 12 volt stereo, it would consume 10 and a half amps (125 watts divided by 12 volts = 10.42 amps), which would explain what you are seeing. You would need about 5X as much battery capacity to get up to 5 hours of playing time. At 120 volts the stereo uses about 1 amp. But if you are converting a 12 volt battery pack to 120 volts, you are still in the same situation, or worse due to the losses incurred during the converting process.
If it was a 12 volt stereo, it would consume 10 and a half amps (125 watts divided by 12 volts = 10.42 amps), which would explain what you are seeing. You would need about 5X as much battery capacity to get up to 5 hours of playing time. At 120 volts the stereo uses about 1 amp. But if you are converting a 12 volt battery pack to 120 volts, you are still in the same situation, or worse due to the losses incurred during the converting process.
12 amp-hours at 12 volts
equals 144 watt hours for the battery capacity. Your stereo requires a stated 125 watts and (depending on how loud you set the volume) should run for 1.15 hours or 69 minutes (144 divided by 125) if the inverter and battery were 100% efficient (which they are not). If the inverter is 50% efficient, the time would be a little over 34 minutes. The power consumption of the stereo is going to depend a lot on the volume you set. The specifications on this kind of stuff is really unrealiable. A boom box or car system is a lot more efficient for battery power. If you get something which runs off of 12 volts you will probably get more battery life. The sound quality may not be what you want though
equals 144 watt hours for the battery capacity. Your stereo requires a stated 125 watts and (depending on how loud you set the volume) should run for 1.15 hours or 69 minutes (144 divided by 125) if the inverter and battery were 100% efficient (which they are not). If the inverter is 50% efficient, the time would be a little over 34 minutes. The power consumption of the stereo is going to depend a lot on the volume you set. The specifications on this kind of stuff is really unrealiable. A boom box or car system is a lot more efficient for battery power. If you get something which runs off of 12 volts you will probably get more battery life. The sound quality may not be what you want though
Power for Stereo Requirements
I am runnig the stereo off the 115V AC outlet in the battery pack. I am a but retarded when it comes to math, but if I used the same formula would it be 125w/ by 115V = 1.08 amps? Would I be better off getting a regular deep cycle or gel battery and hooking up an AC inverter?
I am runnig the stereo off the 115V AC outlet in the battery pack. I am a but retarded when it comes to math, but if I used the same formula would it be 125w/ by 115V = 1.08 amps? Would I be better off getting a regular deep cycle or gel battery and hooking up an AC inverter?
You're math is right but
You haven't taken into account that the 115V you are plugged into was converted from 12V by the inverter. The 125 watts consumed by your stereo is what drives everything. A 115V appliance plugged into an inverter will use about 10 amps of 115V, but the inverter will draw at least 10 times that much from the 12v battery to be able to generate the same 125 watts. This is because watts used = volts x amps. And that's assuming the inverter is 100% efficient - if it's a good one, it's probably more like 90%.
You haven't taken into account that the 115V you are plugged into was converted from 12V by the inverter. The 125 watts consumed by your stereo is what drives everything. A 115V appliance plugged into an inverter will use about 10 amps of 115V, but the inverter will draw at least 10 times that much from the 12v battery to be able to generate the same 125 watts. This is because watts used = volts x amps. And that's assuming the inverter is 100% efficient - if it's a good one, it's probably more like 90%.
look into the steroe itself
Check out the internal power of the stereo itself, nmany stereos run at 9vdc or 12vdc internally, with a built in power supply/transformer, I've run a few home systems in the car by tapping into the power feeds behind the transformer. look for a shematic for the stereo, or open it up and copy down the info on the main transformer, most often they'll have the input/output voltages listed, sometimes just a part number which you can google for the specs. If there's no label use a VOM and check the power on the output side. A lot of the power you use is being wasted through the inverter stepping DC to Ac, then more turning the AC back to DC at either the same, or very close to the voltage you're starting with. Ken
Check out the internal power of the stereo itself, nmany stereos run at 9vdc or 12vdc internally, with a built in power supply/transformer, I've run a few home systems in the car by tapping into the power feeds behind the transformer. look for a shematic for the stereo, or open it up and copy down the info on the main transformer, most often they'll have the input/output voltages listed, sometimes just a part number which you can google for the specs. If there's no label use a VOM and check the power on the output side. A lot of the power you use is being wasted through the inverter stepping DC to Ac, then more turning the AC back to DC at either the same, or very close to the voltage you're starting with. Ken
Numbers
The numbers given are correct. You can only expect an hour or so with this set up. 115 appliances in general use too much current to be run off a battery efficiently. You can get a bigger battery if you want to use this system, but I would recommend getting an automotive 12v system, or a battery powered boom box. If you use a high quality auto stereo, you should have some pretty good sounds. But if you were to add a big amp, you would be in the same position as you are now because they also have high amp draws.
The numbers given are correct. You can only expect an hour or so with this set up. 115 appliances in general use too much current to be run off a battery efficiently. You can get a bigger battery if you want to use this system, but I would recommend getting an automotive 12v system, or a battery powered boom box. If you use a high quality auto stereo, you should have some pretty good sounds. But if you were to add a big amp, you would be in the same position as you are now because they also have high amp draws.
Low power alternative
Rather than install an automobile audio system, we bring along our 20GB iPod, which will play 12 hours on a single charge. However, we do keep it on the table in an Apple iPod dock and feed it power from the boat batteries with a Griffin 12VDC adapter. Our amplifier and speakers are a pair of Yamaha powered computer speakers I had laying around the house. These were originally powered by a 120VAC power supply that output 14 volts and 800 mA, but for the boat I replaced the power supply with a 12 volt power cord from Radio Shack. Although these speakers could be plugged into the headphone jack, we plug them into the "line out" jack on the dock for a little cleaner sound and lower power consumption on the iPod. The whole thing draws about 1 amp. Granted, it isn't powerful enough for playing rock music, Wagner, or the 1812 at boat shaking volume, but we get by with it playing Buffett, Stone, and reggae, and it's at least as good as the expensive portable and battery-powered Altec-Lansing InMotion speakers.
Rather than install an automobile audio system, we bring along our 20GB iPod, which will play 12 hours on a single charge. However, we do keep it on the table in an Apple iPod dock and feed it power from the boat batteries with a Griffin 12VDC adapter. Our amplifier and speakers are a pair of Yamaha powered computer speakers I had laying around the house. These were originally powered by a 120VAC power supply that output 14 volts and 800 mA, but for the boat I replaced the power supply with a 12 volt power cord from Radio Shack. Although these speakers could be plugged into the headphone jack, we plug them into the "line out" jack on the dock for a little cleaner sound and lower power consumption on the iPod. The whole thing draws about 1 amp. Granted, it isn't powerful enough for playing rock music, Wagner, or the 1812 at boat shaking volume, but we get by with it playing Buffett, Stone, and reggae, and it's at least as good as the expensive portable and battery-powered Altec-Lansing InMotion speakers.
besides we all go boating-
To get away form those 100 watt boom boxes. you can blow your self out of the boat with 5 watts. just does not make any sense.
To get away form those 100 watt boom boxes. you can blow your self out of the boat with 5 watts. just does not make any sense.
yeah but...
Every now and again something comes on that's just made to crank it up a bit. Kinda like the difference between listening to children of the sun in mono and listening to it with good headphones on, you lose the whole effect. Ken.
Every now and again something comes on that's just made to crank it up a bit. Kinda like the difference between listening to children of the sun in mono and listening to it with good headphones on, you lose the whole effect. Ken.
Stereo was a Gift
The 120W JVC stereo was a gift for my boat so I am trying to work with it. I was orginally looking for something to use with my iPod and the person who gave me the stereo thought that all I needed was an Aux input. Now that you all have ecuated me about power usage, converters, inverters and electric math, I see that it is not the best solution. If I could get into the stereo power source and make it into 12 volt that would be great. BTW-the person who gave me this stero is my only crew member so I want to keep her happy.
The 120W JVC stereo was a gift for my boat so I am trying to work with it. I was orginally looking for something to use with my iPod and the person who gave me the stereo thought that all I needed was an Aux input. Now that you all have ecuated me about power usage, converters, inverters and electric math, I see that it is not the best solution. If I could get into the stereo power source and make it into 12 volt that would be great. BTW-the person who gave me this stero is my only crew member so I want to keep her happy.
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