Twice

 

I don't learn so good!

 

How long can you run a full system for with the car off would you guys guess? I know everyone's experience would be different, but if you had to guess? Is 10 mins safe? 20? 30?
We know from skip an hour is too long (confirmed twice)

 

[QUOTE]Originally posted by FF2Skip

 

[QUOTE]Originally posted by Ajjra
How long can you run a full system for with the car off would you guys guess? I know everyone's experience would be different, but if you had to guess?

 

My system at full blast will last 8 minutes. Tried it with my spare battery (fully charged)

 

Didn't know that. I'll be mindful of that, thanks...

 

[QUOTE]Originally posted by Ajjra
How long can you run a full system for with the car off would you guys guess?

 

It's true that a cap can recharge faster than an amp draws current (in most reasonable cases) since an uncharged cap looks esentially like a short (and we all know how much current flows in a dead short!). I'm not quite sure what you mean, though, about a higher voltage drop.

Let's put some numbers to all of this (realistic ones or not) to make visualization easier (warning: major oversimplification and nonstandard use of terms used here). Let's say the alternator is capable of providing 300A (after all of the other accessories have been powered), and is obviously a replenished supply of current. The battery and cap are only replenished if there is extra power from the alternator after supplying the amp with its power demands. Let's say the battery holds 50A and the cap 10A.

Say our system requires 280A continuously, with short peaks of 320A once a second form the music being played, the battery and cap are fully charged. A beat hits, 300A is pulled form the alternator, 10A from the cap, and 10A from the battery. But when the beat is not being played, the amp takes 280A form the alternator, the cap gets 10A and the battery gets 10A (for a total of 300A from the alternator, replenishing everything back to its original state, and away we go again.

Now what happens when we play music that requires 330A for the beat instead. Beat hits, 300A comes from the alternator, 10A form the cap, and 20A from the battery. When the beats not playing, the alternator supplies the amp with 280A, the cap gets 10A, and the battery gets the remaining 10A (for a totoal of 300A form the alternator). but now the battery is 10A short and only holds 40A. So we hit another beat, and again, the battery comes up 10A short, now only holding 30A. Eventually, the alternator will not be able to supply enough juide between beats to keep the battery and cap charged and will eventually run them down completely.

In the first case, the alternator has enough juice left over to continually resupply the cap and leave the battery alone. In the second case, it's a losing battle and your system will begin to suffer from a low voltage condition as the battery and cap are no longer recharged. It's a very real situation, but the solution (in this particular case) is not adding in more caps, it's making sure the alternator is supplying enough juice.

[QUOTE]Anyway, it is my "expert" opinion that the s2000 does not need a capacitor.

 

Not to mention that your alternator will fail earlier because of the demand that is being placed on it in the example above...

Best way to solve this power problem is not with a cap, it's with a larger alternator or better yet a second one. <--- I did that in a previous car with no a/c. NEVER had a power shortage again....