400 watts how many amps?
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mudder
400 watts how many amps?
im thinking of buying a 400 watt amp for my truck that has a 95 amp alternator.will i need another battery and a bigger alternator?not sure if i do or not one guy told me 100 watts draws 17 amps so 400 watts would draw 68 amps.so i would have 27 amps to spare but im told i need an extra 40 amps what do you think?thanks in advance..
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Shaft
The formula for calculating power is P=I*E, or Power = Current * Voltage. So for a 400 watt amp you would divide 400watts by 12v and you get 33.3 amps, not 65 like you think.
But then again, 33.3 amps is only at peak power. Most vehicle electrical systems can handle that. But here's something else to consider. While the engine is running the alternator supplies the power to the vehicle's electrical system. Most cars charge at 14 volts. Now you are looking at a current draw of 28.5 amps.
Let your head lights be your guide. If they dim heavy when you key up, then think about upgrade your electrical system. The first thing I would do is upgrade the battery to something like a red top Optima.
But then again, 33.3 amps is only at peak power. Most vehicle electrical systems can handle that. But here's something else to consider. While the engine is running the alternator supplies the power to the vehicle's electrical system. Most cars charge at 14 volts. Now you are looking at a current draw of 28.5 amps.
Let your head lights be your guide. If they dim heavy when you key up, then think about upgrade your electrical system. The first thing I would do is upgrade the battery to something like a red top Optima.
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SmallTruckBigRadio
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mudder
ok
Shaft wrote:The formula for calculating power is P=I*E, or Power = Current * Voltage. So for a 400 watt amp you would divide 400watts by 12v and you get 33.3 amps, not 65 like you think.
But then again, 33.3 amps is only at peak power. Most vehicle electrical systems can handle that. But here's something else to consider. While the engine is running the alternator supplies the power to the vehicle's electrical system. Most cars charge at 14 volts. Now you are looking at a current draw of 28.5 amps.
Let your head lights be your guide. If they dim heavy when you key up, then think about upgrade your electrical system. The first thing I would do is upgrade the battery to something like a red top Optima.
ok well on eat coast amps web site they say 400 watts will draw 60 amps heres the link..[Please login or register to view this link]
ps i use to run a 400 watt amp before i blew it up and it killed my stock 95 amp alternator and it would dim my head lights at night.
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dud muck
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If the amplifier were 100% efficient, then it would consume 33amps.Shaft wrote:The formula for calculating power is P=I*E, or Power = Current * Voltage. So for a 400 watt amp you would divide 400watts by 12v and you get 33.3 amps, not 65 like you think.
But a 100% efficiency is a pipe dream. The 12.5v transistors in these amplifiers typically get 40-45% efficiency, which means you must put in a bit more than double the power you want to get out. The wasted power is heat.
The only way to get more efficiency is to use 28volt or 50volt pills, or tubes.
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howcome "destinated" isnt in the CB-slang dictionary?
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Stroker
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Duck Commander
i need a bigger alt i guess i duno what size mine is on my Blazer but ive got 2 yellow top optima batts and all im runnin is a DaveMade 1x4 and my headlights dim perty good at night. But im plannin on gettin a 10 pill before long so i need to upgrade to be able to run that thing, i would like to have an adjustable voltage regulator on mine to if i could run my stuff off of 15.5 or so volts that would be nice real nice. Got this local crackerhead around here he went and got him a damn 2x4 DaveMade so i gota hurry upn do sumpn to get bigger than him.
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Shaft
Duck, I have 2 questions for you.Duck Commander wrote:i need a bigger alt i guess i duno what size mine is on my Blazer but ive got 2 yellow top optima batts and all im runnin is a DaveMade 1x4 and my headlights dim perty good at night.
1, how old are those yellow top batteries?
2, are those the only batteries you have in your vehicle?
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Shaft
OK, I wouldn't worry about the batteries just yet, but what I am about to tell you is something to consider.Duck Commander wrote:Maybe 6 months old and yes they are the only 2 in my vehicle.
Optima yellow top batteries last maybe about 2 years. I personally had 2 yellow tops in parallel in one of my cars and I experienced problems with them when they got to be about 2 years old. I also have sold many of those batteries in all my years of work in high end car audio, and I've seen their performance.
Yellow top batteries are not good for starting. Buy a red top for that. If you want to use them as a secondary battery when using an isolator, then they are OK.
I would try doing this. Disconnect one of your batteries and see how the car starts and runs. Then try running the other battery solo. You might be surprised at what you find.
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Stroker
What year and what engine in your blazer. You need a 200 amp alt just to run a 8 pill.. I can get you a 140 amp w/ adjustable regulator for a decent price . The if you do go bigger at-least you can run your driver of the 140.
My wife's truck has a yellow top for her 2x4 and car audio used a 200 amp isolator I'm seeing 15.2 at both batteries.
My wife's truck has a yellow top for her 2x4 and car audio used a 200 amp isolator I'm seeing 15.2 at both batteries.
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Duck Commander
Shaft if i do that im guna have to charge my battery every nite rite? Also i think those batteries have a 3 year warranty on em so maybe they will go bad in 2 years and i can swap em in on some Red Top's u think?
Stroker it is a 1987 K-5 with the TBI 350. I wuz planning on getting a 200-250 amp alt sometime just gota sit down and check around and find not neccessarilly the best priced but the best alt for what i need. I hear quite a bit about the Leese NaVille's so im guna check into them then i duno what else to check into but i gota do it perty quik.
Stroker it is a 1987 K-5 with the TBI 350. I wuz planning on getting a 200-250 amp alt sometime just gota sit down and check around and find not neccessarilly the best priced but the best alt for what i need. I hear quite a bit about the Leese NaVille's so im guna check into them then i duno what else to check into but i gota do it perty quik.
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626s
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Stroker
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FordPSD60
If your battery is being charged then why is buying a better battery needed?
I have a new F-250 with the diesel engine. It has 2 batteries. I assume it has 2 batteries because diesels have high compression and needs the added power to crank it.
Or are the 2 batteries there because it has a higher amp alternator and these trucks are expected to be operating more power accessories?
I have a new F-250 with the diesel engine. It has 2 batteries. I assume it has 2 batteries because diesels have high compression and needs the added power to crank it.
Or are the 2 batteries there because it has a higher amp alternator and these trucks are expected to be operating more power accessories?
