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My setup is as follows:

Pioneer AVH-P4100DVD
2007 OEM battery
OEM amp
OEM sub
OEM speakers

My battery has not exhibited any signs of weakness and the last time I took it to the dealer for an oil change, they checked the battery and it was good.

My question is this; my new HU can play DVD's and I was wondering approximately how long I can watch a DVD with the car NOT running? I know this is a subjective question, but I was just wondering from a hypothetical point of view based on the power required to run the system.

I'm definitely not an electronics expert, but would adding a capacitor to my system give me additional time?

Advice appreciated!
 

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2008 Element EX AWD TRP
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From a hypothetical point of view, the run time is the ampere hour rating of the battery divided by the load current.

The load depends, not on the models of your equipment, but on how loud you crank it. There is no spec on maximum input load current on the page you reference. The spec you reference says the DVD player has its own amplifiers. If the DVD player were wired directly to the battery, assuming that the amps are 50% efficient, it would draw an max current of (22W x 4 x2)/12V=14A. (Personally, I think you'd have to be a sadist to crank up the output to this level, which using good speakers, would represent 2-3W of acoustic power - enough to permanently damage your hearing- while watching a 7" LCD image.)

Anyway, continuing this hypothetical discussing, the Reserve Capacity Minutes is how long a battery will power a 25A load before the output voltage drops to 10.5V. If you can find this spec for the Honda OEM battery, you could estimate that the DVD player alone would work for about twice the RCM.

Since we don't have hypothetical vehicles, from a practical viewpoint, why don't you try it in your driveway? Use a digital voltmeter across the battery, measure how long it takes for the terminal voltage drops to 10.5V, and call that your max run time. (Keep a battery charger handy:lol:.)

Finally, adding a capacitor as a power buffer might reduce ignition noise, and may improve the dynamic response of the audio system; it won't extend run time. Capacitors are "lossy" (self-discharge). Adding one will decrease your run time.
 

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it depends on volume. the most powerful device is amplifier and subwoofer. dvd monitor needs less. imho 3-4 hours for battery isn`t problem
 

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Finally, adding a capacitor as a power buffer might reduce ignition noise, and may improve the dynamic response of the audio system; it won't extend run time. Capacitors are "lossy" (self-discharge). Adding one will decrease your run time.
you needn`t it. it`s choice for sound pressure competitions, when you need huge amount of energy for big "BOOM"
 

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The only positive way to be 100% sure how long it will last with your specific setup, is to test it.

There is no other way.\\

Sit in your driveway with a charger and power cord at the ready. Turn it all on , then enjoy a movie. When it stops working, you will know exactly how long it will last. No guessing, no math errors, no question, just fact.

Dom
 

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I just took my wife's 2007 CR-V to dealer for oil change & trans oil change at 30k. They actually did a free battery test during service, & found out battery is lower than spec cold cranking power. I got a new 100 month warranty Honda battery under warranty.

CR-V never had any cranking problem, included starting in cold winter morning.
But I won't complain about a brand new $127 100 month battery under warranty. ;-)

Battery crank power test at dealer is going to be part of my 30K maintenance check list for my 2009 E. Hopefully I could get a new battery at that time also.
 

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reserve capacity of the factory battery isn't very much... i would make provisions for more juice if you intend to push the issue.
 
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