battery gage doing the river dance | Page 2 | Ford Explorer Forums - Serious Explorations

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battery gage doing the river dance

Billy177 said:
For an amplifier to be able to produce power, it must consume power. In the case of the car audio system, we are limited to about 12V (up to 14.4V in some vehicles). Given even the most efficient Class-D amplifiers, operating at over 80% efficiency, we need about one-Amp of current for every 10W being produced. So, a 1,000W amp requires about 100-Amps of current. Remember, this is an approximation and depends greatly on the efficiency of your amplifier.

Ohms law states that for every Amp of current flowing through an Ohm of resistance, one Volt will be dropped across the load. If we double the current, we get more voltage drop. Conventional lead-acid batteries have somewhat high internal resistances, which is why the output voltage drops as the current draw increases. If you put an analog voltmeter on your car’s battery as you start it, you will see the voltage drop from 13.6V down to the mid 11s while the starter motor is running. It’s also the same reason why our headlights and dash lights dim when a stereo is drawing large amounts of current from the electrical system.

A capacitor is similar to a battery in that it can store an electrical charge. However, its internal resistance is much lower than that of a battery, so the voltage drop when large amounts of current are drawn from it are much smaller, almost negligible.

The other problem with batteries is that there is a limit to how much current can be drawn instantaneously. Batteries are slow-motion devices; meant to store a charge for a long time. A capacitor is the opposite. It can completely discharge itself almost instantaneously, given the correct load conditions.

So what does this do for us? A capacitor is installed in parallel with the battery, preferably as close as possible to your amplifier. When the amplifier requires a great deal of instantaneous current (more than the battery can supply), the capacitor supplies it. This helps improve the transient (dynamic) response of the amp, but doesn’t help in long-term (more than a second) power delivery.

the rest is here http://www.pasmag.com/news/get.asp?ID=457&tsectionkey=
since it only drops for a second when the base hits and the base is only drawing 12.5 amps this is all you need. an example of this is if you turn your lights on the battery gauge will drop for a second then come back up, this is the voltage regulator telling the alternator to put out more juice

I hope you didn't just copy and paste all that from somwhere :thumbdwn:
However where's the proof of how much a cap helps? Oh that's right, cuz there's no electrical equivalent to a wet fart :confused:
 



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batcap is only advantageous over a battery due to size and weight
 






so do i need a new alternator and a second battery or should i buy your used batcap?
 






all are about the same price... personally id get a new alternator, but for me its second on the list, first is a bigger, stronger, battery
 












Almost solved!

Almost solve the problem. I bought a Red Top and the battery gage is not moving anymore, but when i have my headlight on; it start dancing again. So my next step is to install a 200w alternator. I made a mistake when I bought a referbish alt from Advance Auto about a year ago. Do you guys know where i can purchase a 200w alt from? Thanks for the very helpful information.

ohh- another question: What do you guys think of Eclipse radio's. I was looking at the 5444 model to replace my old sony deck.

Thanks again.
 






let me know if that fixes it... my problem is right about there... only dims with the HL's on.. it dims with them off if i put the bass too high

ebay sells alternators
 






i did copy and paste it as i had previously stated
"the rest is here http://www.pasmag.com/news/get.asp?ID=457&tsectionkey="
 






Today i used a mutimeter to test the battery and alternator output and this is what i got:

battery, alternator
car off ...........................................................12.36 12.32
car on: ...........................................................14.28 14.36
car on, max AC, headlights, & turn signal ............. 14.27 14.35
car on, max AC, headlights,turn signal & radio @40..14.15 14.25
car on, max AC, headlights, turn signal &radio @55..13.12 13.64
radio @60...12.97 13.09

It seem that the ALt tested fine until i turned the radio volume up.
What do you think the cure is to my sickness.
Ex. Cap, Alt...etc....
 












if you have a noticeable "problem" i highly doubt less than 5 farads will make any discernable difference (the alt will still be destroyed either way) but 5 or more would probably make it workable for a while. less than that and its still goign to suck.

so get an alt, or better yet imo an auxiliary battery of some kind
 






Here you go, real world testing a cap hurt spl performance.....
http://forum.soundillusions.net/showthread.php?t=39716

when a power acoustik cap 2.4 farad was removed they gained .2 db on the mic
when they removed their batcap 400 they gained they gained another .1db

now as I've said before for car audio, caps suck period.... now there's some real world experience printed up on the net..... [/kickingdeadhorse]
 






The saga continues......Today I upgraded the "Big 3". with 4 gage wire.
Bat(-) to frame,
Alt(+) to Batt(+) with fuse,
Alt(-) to frame

My gage is still dancing. I was disapointed with the results. But i must say that when im driving the gage dont shake as much. Its just when im at idle it bounces. Especialy with my headlights on.
Im stuck on stupid, because i dont know what to do. I upgraded the battery to a redtop, did the big 3, and have a .5 cap. I guess the only thing left is the alt.
I looked on line a saw a few brands- Powermaster, mean green, Mr Alt...etc... Which one is the best. I know alot of companies say thier brand is rated at 200w but only gives you 130a.
Any advice will glady be appreciated.
This is becoming a nerve wrecking experience..
 






well it says 200amps... but thats its max output... all companys post their max output, and idle output is yeah somewhere around 130 amps.

i say as long as its a high current amp youll be fine
 






Well i guess im on my way to a new Alt. Ill keep you posted.
thanks.
 






riverst said:
The saga continues......Today I upgraded the "Big 3". with 4 gage wire.
Bat(-) to frame,
Alt(+) to Batt(+) with fuse,
Alt(-) to frame

My gage is still dancing. I was disapointed with the results. But i must say that when im driving the gage dont shake as much. Its just when im at idle it bounces. Especialy with my headlights on.
Im stuck on stupid, because i dont know what to do. I upgraded the battery to a redtop, did the big 3, and have a .5 cap. I guess the only thing left is the alt.
I looked on line a saw a few brands- Powermaster, mean green, Mr Alt...etc... Which one is the best. I know alot of companies say thier brand is rated at 200w but only gives you 130a.
Any advice will glady be appreciated.
This is becoming a nerve wrecking experience..

Big 3 and the battery was a good necessary step. I doubt you needed the cap.... .5 farad isnt that much anyways.... but still it can help. An alternator is almost inevitable, you'll benifit from it the most. I think once you do that you will find the single greatest improvement. You are always going to get a little voltage drop at idle, it will always happen, so just know that when you do upgrade.

GL
 






Thanks for the info. As soon as i get the cash, ill get the Powermaster Alt. It seems like the best brand due to it puts out 125w at idle and 200w peak. I went to this site called www.MECHMAN.com and there alt are trash. the 200w model only puts out 45w at idle. So im praying that powermaster keeps its word and delivers 125w at idle and 200 max.
 






FYI, alternators are rated in amps, not watts :D

Also, check on www.termpro.com forums and see if you can contact Dominik (sp?) Iraggi... he handwinds custom alternators that are supposedly superior to almost anything else out there... maybe worth a shot... also www.ohiogen.com makes some very nice alternators.
 






Thanks for the Correction.
Ill check it out.
Thanks
 



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on tpro check the batteries/alt forum -- lots of good info if you search too.
 






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