Battery to play with engine off

[Thnking 10+ year member]

AH isn't really going to give anyone any good information about a battery dioscharge when the car is off; unless you have the volume on really low so the battery lasts 8 or 10 hours.

You would have to use Peukert's Formula to determine the discharge of the battery.

T=C/I^n

Modified to:

T=C/(I/(C/R))^n x (R/C)

T=Time

C=Capacity in AH

I=Average current (load)

R=AH rating (ie 20 hours, 10hours, 8hours, etc)

n=Peukert's number (I would just use 1.2 - the average- to simplify things)

So let me give you an example of a Kenitik battery with only a 30amp average load:

the HC2000 http://www.kinetikaudio.com/hc2000.asp

It looks like it give your a AH based on 100 hours, it's hard to tell because all of their information is vague, but I don't think it's based on 50 or 20 hours.

T=102/(30/(102/100))^1.2 x (100/102) = approx 1.75 Hours of 100% discharge.

Since we need to keep the depth of discharge around 15% at Max, a rough estimate of the playable time you can use the battery for is:

1.75hr x 15% = 16 minutes.

So at 16minutes, the battery voltage will essentially be at around 10V with a 30amp load....this is a rough estimate.

 

[coolahan 10+ year member]

Anyone elses head hurt? //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[azimuth 5,000+ posts]

Oh i was joking bout the seconds.. if you didn't pic up the sarcasm.

lol. i realize you couldn't kill it in seconds. when i got my new battery, i bumped my shit hard just to see how long it would last. not even 10 minutes.

 

[mlstrass 5,000+ posts]

Bigger issue is that you'll fry your alternator a LOT faster. Most HO alt companies will tell you it voids your warranty if you crank the system with the car off. Kills the diodes or rectifiers or something....

 

[xtremekustomz 10+ year member]

go here and check the out. You can call Ray and talk to him about it as well. http://www.batcap.net

 

[audiolife 5,000+ posts]

AH isn't really going to give anyone any good information about a battery dioscharge when the car is off; unless you have the volume on really low so the battery lasts 8 or 10 hours.You would have to use Peukert's Formula to determine the discharge of the battery.

T=C/I^n

Modified to:

T=C/(I/(C/R))^n x (R/C)

T=Time

C=Capacity in AH

I=Average current (load)

R=AH rating (ie 20 hours, 10hours, 8hours, etc)

n=Peukert's number (I would just use 1.2 - the average- to simplify things)

So let me give you an example of a Kenitik battery with only a 30amp average load:

the HC2000 http://www.kinetikaudio.com/hc2000.asp

It looks like it give your a AH based on 100 hours, it's hard to tell because all of their information is vague, but I don't think it's based on 50 or 20 hours.

T=102/(30/(102/100))^1.2 x (100/102) = approx 1.75 Hours of 100% discharge.

Since we need to keep the depth of discharge around 15% at Max, a rough estimate of the playable time you can use the battery for is:

1.75hr x 15% = 16 minutes.

So at 16minutes, the battery voltage will essentially be at around 10V with a 30amp load....this is a rough estimate.

playing music cant be stamped out into a formula (real world imposible)...i have seen the little 600's power systems of 2000 watts + for over 20 min at moderate volume. kinetiks its a c/20 rating just like everyone elses .... for some one who "knows" so much i think you would know make ups of batteries. directly what gives a battery more capacity? plates and how many a battery has...

 

[Thnking 10+ year member]

playing music cant be stamped out into a formula (real world imposible)...i have seen the little 600's power systems of 2000 watts + for over 20 min at moderate volume. kinetiks its a c/20 rating just like everyone elses .... for some one who "knows" so much i think you would know make ups of batteries. directly what gives a battery more capacity? plates and how many a battery has...

This is a real world example, and someone can use a formula with an estimated average load.

But someone needs to estimate average current draw. Your example means nothing to the real world – you would need to specify the AVERAGE draw over 20 minutes.

Also, c/20 is a joke spec, unless you’re music is low enough to make your battery last for 20hours before reaching the spec’d DOD.

As far as capacity goes in relation to plates, its surface area not plate #.

 

[mtdewelf 10+ year member]

*I usually left car running if I was bumpin at parties*- Any reason you can't?

being the portable DJ for parties is cool, but not so safe.

 

[acold7dusta 10+ year member]

all i got to my electrical system is a yellow top. running i get 14.8 volts, off i get 12.8 volts. with it off my battery has lasted 5 hours at a bonfire and showed no sign of stress, but then again i only have 400 rms to my sub and 120 per speaker, soi dont drawthat many amps ( compared to some of you)

anyone run outta juice at the drivein? that would definately **** lol

 

[audiolife 5,000+ posts]

This is a real world example, and someone can use a formula with an estimated average load.But someone needs to estimate average current draw. Your example means nothing to the real world – you would need to specify the AVERAGE draw over 20 minutes.

Also, c/20 is a joke spec, unless you’re music is low enough to make your battery last for 20hours before reaching the spec’d DOD.

As far as capacity goes in relation to plates, its surface area not plate #.

its a VERY common spec for a battery (optima hawker nsb all use the same spec)...if you are so SmArt you would Know I GeT TiReD Of PeoPle Who SaY ThiNgs LikE Low VoLtAGe NevERHurTs AnyThing BlAh BLaH BlAh. in the production process of plates you are right about the surface area but as they go together the battery with the most plates wins in that reguard unless we arent talking about same sized anything or we arent talking lead acid

 

[Thnking 10+ year member]

its a VERY common spec for a battery (optima hawker nsb all use the same spec)...

That’s right, and many years before car audio mainstream began using batteries as a source for their stereo, the AH spec was useful (for batteries as a secondary buffer source). But it’s not for people who use batteries for running their stereo with their engine turned off.

Puekerts formula is used by anyone when their discharge rate is not defined by CCA, HCA, MCA, PCA, or AH…which is basically anyone in car audio.

if you are so SmArt you would Know I GeT TiReD Of PeoPle Who SaY ThiNgs LikE Low VoLtAGe NevERHurTs AnyThing BlAh BLaH BlAh.

LOL, I have no idea what this has to do with this conversation.

in the production process of plates you are right about the surface area but as they go together the battery with the most plates wins in that reguard unless we arent talking about same sized anything or we arent talking lead acid

When all is said and done, the surface area of the plates is the main factor, not number of plates. A good example is a grid pattern plate vs a smaller open cell plate. There can be up to a 4x difference in surface area.

That’s reality.

 

[audiolife 5,000+ posts]

That’s right, and many years before car audio mainstream began using batteries as a source for their stereo, the AH spec was useful (for batteries as a secondary buffer source). But it’s not for people who use batteries for running their stereo with their engine turned off. Puekerts formula is used by anyone when their discharge rate is not defined by CCA, HCA, MCA, PCA, or AH…which is basically anyone in car audio.

LOL, I have no idea what this has to do with this conversation.

When all is said and done, the surface area of the plates is the main factor, not number of plates. A good example is a grid pattern plate vs a smaller open cell plate. There can be up to a 4x difference in surface area.

That’s reality.

i know you wouldnt know what to do with it its apparent lmao

 

[danz24 10+ year member]

Wouldnt a simple indicator that you should stop playing the music loud is to look at the voltmeter? I know some decks have a built in one and if it starts getting lower than 11 volts I would start the car or stop playing music.

 

[tEh koRnDog 5,000+ posts]

i burned my battery just by leavin the door open for 10 minutes

 

[tEh koRnDog 5,000+ posts]

taht is why since that i recently have purchased a new battery