Running Stereo without battery.

BillT

New member
I was wondering if it would be possible to run the electronics in my YJ off of a 120V power source. I was thinking of using a computer power source (120V AC to 12V DC) and just connecting the wires to the battery terminals from the Jeep. I just want to be able to play the stereo, not turn it over.
 

So, you are trying to play your stereo without running down your battery? You'd be better off buying a cheap battery charger and hooking it up when playing the stereo. I'd be worried about over charging with the computer power source as it wasn't designed for charging. I could be wrong.
 
Ya. I wouldn't worry to much about running the battery down. I can play my stereo for 4 hrs and I have two amps. If you want to you can hook a 2amp charger to it and be fine but you will still have to turn the key back.
 
I want to take the battery out of the equation. We party out at the farm and it'd be nice just to run an extension cord and plug it into a power source. We get music all night long and I'm not putting my strain on my battery recharging it.
 

I would bring a house hold stereo that you could just plug into the outlet.
 

Isn't completely draining a battery bad for it? I can't believe no one has tired this before...
 
Yes it can be done, in fact Schumacher makes a 120vac/12vdc converter that you just plug into your power port or lighter. It's pretty much a trickle charger that puts out 2amps but it should do good for what your wanting.
 

I have a car stereo in my shop it runs of a small power supply I picked up at radio shack $45. so yes it can be done
 
I added a 12VDC computer backup battery in mine and a timer on the radio so it shuts off automatically after 3 hours.
 
you could just put in a second battery, wire up the isolation circuit, if you use a deep cycle and put your radio and maybe a few other accessories on that battery it would last for you... then auto charge when you started the jeep to go where ever.. and....... you'd have your main battery for starting your jeep!
 

back up the truck... You need to be careful here! regular battery chargers can fry stereos, they are pulsed DC, not filtered Notice that nasty Buzz? it's straining your power amp. Get a good battery minder capable of 20 amps designed for this type of duty. it will supply the bulk of the power you need, work as a charger when you need one and not strain your electronics or allow your battery to cook out. The problem with charging the battery is you boil out the water and cause sulfite to form on the plates. when the plates are close to 25% sulfited the battery is shot and will only charge up to 65 to 70% of its warm capacity, that means its cca is about 30%.
 
back up the truck... You need to be careful here! regular battery chargers can fry stereos, they are pulsed DC, not filtered Notice that nasty Buzz? it's straining your power amp. Get a good battery minder capable of 20 amps designed for this type of duty. it will supply the bulk of the power you need, work as a charger when you need one and not strain your electronics or allow your battery to cook out. The problem with charging the battery is you boil out the water and cause sulfite to form on the plates. when the plates are close to 25% sulfited the battery is shot and will only charge up to 65 to 70% of its warm capacity, that means its cca is about 30%.
true to an extent, there are chargers that are not chipped as we called it (sine wave has a dip where it falls off).... depending on the circuitry and filtering.. those capacitors, zeners, and such can clean the charge cycle better than your alternator, which by the way is AC rectified.. same thing your shaking your finger at.. I do see your point in being careful WHAT type charger your going to use, and if its not fully regulated, true, it will cook the battery... the new pulse chargers are great.. they are regulated, and only pulse in the charge voltage, actually fine tuning your battery.. and will most of the time, bring a bad battery back to life.. if it tests bad, throw the big charger on it to get a little voltage, then put the pulse charger on it to finish it up... my 12vdc power supplies put out a better sine wave than a 12v battery... extremely clean..
 
frhrwa said:
true to an extent, there are chargers that are not chipped as we called it (sine wave has a dip where it falls off).... depending on the circuitry and filtering.. those capacitors, zeners, and such can clean the charge cycle better than your alternator, which by the way is AC rectified.. same thing your shaking your finger at.. I do see your point in being careful WHAT type charger your going to use, and if its not fully regulated, true, it will cook the battery... the new pulse chargers are great.. they are regulated, and only pulse in the charge voltage, actually fine tuning your battery.. and will most of the time, bring a bad battery back to life.. if it tests bad, throw the big charger on it to get a little voltage, then put the pulse charger on it to finish it up... my 12vdc power supplies put out a better sine wave than a 12v battery... extremely clean..

Agreed.
 

???? A 12 vdc power supply doesnt put out a sine wave. They put out DC... A sine wave is AC or modulated DC depending on the set point of the wave form. And "WE" dont call them Chipped, never did, I was one of the people who worked out the bugs on designing them. A typical Battery charger puts out a half wave unfiltered pulse, the voltage regulator in or on an Alternator works as a "chopper" filter, which is why you dont hear any buzz on your audio equpment, but do ocassionally hear an extremely high pitched whine, which is the result of the arcing of the brushes not an AC component.
 
I've never seen a good quality battery charger pulse unless it was a deep cycle battery charger. I can watch with a lab scope, volt meter , etc. all mine are a steady 14.0 volts at which ever amperage.
 
A typical Battery charger puts out a half wave unfiltered pulse, the voltage regulator in or on an Alternator works as a "chopper" filter,

The voltage regulator in an alternator is on and off. Nothing to do with the type of voltage it puts out. The rectifier or diodes three is what converts it from ac to dc. By filtering out the lower ac wave. The voltage reg just turns on and off depending on the supply requirements of the system.
 

???? A 12 vdc power supply doesnt put out a sine wave. They put out DC... A sine wave is AC or modulated DC depending on the set point of the wave form. And "WE" dont call them Chipped, never did, I was one of the people who worked out the bugs on designing them. A typical Battery charger puts out a half wave unfiltered pulse, the voltage regulator in or on an Alternator works as a "chopper" filter, which is why you dont hear any buzz on your audio equpment, but do ocassionally hear an extremely high pitched whine, which is the result of the arcing of the brushes not an AC component.
sorry, didn't realize there were engineers out there.. true, sine is ac and.... All waves are made by adding up sine waves. The sine wave has a pattern that repeats. The length of this repeating piece of the sine wave is called the wavelength. The wavelength can be found by measuring the length or distance between one peak of a sine wave and the next peak. The wavelength can be found in many other ways too. the output of "most" chargers is a square wave, which is a kind of non-sinusoidal waveform, or pulsed waveform.. the caps (filters) help by smoothing out that chip in the peak of the wave.. "see that word chip again"... WE did call them chipped, and I also have been in the Electronics business, since 1964! so call it what you want.. doesn't matter, end result is the same..
 
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