Although my audio system is on hold at the moment (Suspension is more of a pressing concern at the moment, and I just paid for schooling), that doesn't mean I can't prep a battery box in the mean time for a new battery (Pretty sure the current one is cooked, heavy, up high and out back). So for any of our electrical aces, or sound gurus, do you think this would be sufficient as a battery: http://www.kinetikaudio.com/2009/product.asp?P=KHC600&C=1 - http://www.kinetikaudio.com/2009/product.asp?P=KHC600&C= 1

Bare in mind that while I will have a fair bit of audio stuff in the car, I don't intend to be playing it overly loud, and I do have an upgraded alternator to try and keep her juiced. Just basically wondering if that should be sufficient to turn her over in the morning, as the next size up is 26 pounds, it would be nice to save those 8 pounds.

Why...lol, depends on how much in amps your driving, Cap is good to have, again get a Optima Yellow and you'll be fine

Again...what are you running, how much amp's, etc...I play my system LOUD and have a 6 channel JBL at 600 watts...have never even come close to draining.

I know any audiophile will suggest to upgrade the world...Right Zander, Tyler & Waylon...lol

I see a trend..."Optima Yellow Top"

YellowTop Group 75/25 Dual Purpose (Deep Cycle & Starting):

Weight 37.8lbs.
Length 9.38inches
Height 7.75inches
Width 6.81inches

http://shop.optimabatteries.com/products/productdetail/YellowTop+Group+75/25+Dual+Purpose+%28Deep+Cycle+%26+Starting%29/part_number=D75/25/1737.0.1.1.62466.0.0.0.0?pp=8 - Or

INTERSTATE BATTERY MEGA-TRON PLUS - 85 MONTHS - 700 CCA

Had me thinking Colby...Yellow Top worth the Weight...haha, get it

Fire451 wrote: if you need a cap I have one here that is still brand new in the package and will sell it cheap (unless brian still has/wants dibbs)

Cheers man:)...no need

Capt Fiero wrote: Wow nice to see Mr Fire451 posting up, haven't seen you in a while.  You and the ladies should come out on the 25th with everyone. 6 Fiero's will be on the track racing.

Performance driving

Cheese wrote: Bassman wrote: Had me thinking Colby...Yellow Top worth the Weight...haha, get it No? Do you mean Tristan?

Kidding, of course.

Both of ya..Tristan's the one looking and Colby advised on spec

lol

Aw, and here I thought you were just ignoring lovely little Tristan.

Keep in mind with your calcs that music is about 30% duty cycle. Meaning, if you run your 600W flat out, it will only suck about 200W for real (15A).

So it's like leaving your lights on basically.

As far as batteries go, my limited understanding is this:

The tradeoff is between deep cycle and starting amps. A deep cycle has less plate surface area, but thicker plates. The oposite is true for a starting battery...mores surface area but thinner plates (For any given battery package size). The combo batteries are just that, some thin, some thick, or all medium thickness.

Caps help reduce the transient requirements on the power system (Battery and altenator). They are best when mounted really close to the main power device, in this case the pwer amp. This is because of the impedance of longer leads lessens the transient help the cap can give.

It should 'clean up' and base distortion due to lack of supply which can occur in setups with long, small supply wiring to the amp. Another way to look at it is if you buy the big cap, you can tell the guy trying to sell you the 4/0 cable for you amp the big finger, 'cause really you only need #10 (Which will easily pass 30A). This will more than pay for the cap in a longer supply run.

It won't help in your amp-hour energy requirement.

If it was me, I'd stick with the smaller deep cycle battery, and a larger altenator, plus a nice juicy big cap stuck next to the power amp.

1 more thing...if you run this setup, have a really good low impedance ground from the power amp to the head unit. This will prevent ground rise oscillations from occuring.

Chay

Yup they're heavy alright. Cake...eat it....you get the idea.

batcaps? Is this a composite word, or are you looking a super(ultra)capacitors?

Chay

I know that device as a super or ultra capacitor. Of course, it may be a bit different, because the ones I was looking at were 20F and above, and could be drained right down. Also, charging time is limited only by thermal characteristics of the unit (In other words, very high current charge) yeilding charge times of less then 5 seconds from a source capable of it.

It's starting to be the solution to wasted brake energy in hybrid vehicles because they can absorb large amounts of charge in small amounts of time (Unlike a nicad/nmh, etc), and they are light as you're said (Weight is the enemy of efficiency in a vehicle).

I was looking at a bank to run my electric bike for 30 minutes at 6A, 30V and it was going to cost $2500. I think you'll run into the same cost prohibitive numbers if you look at the capacity you'd need.

Lets examine a starting situation:

 Let's say you want 500A for .5 seconds, then 150A for 2 seconds, and you need the voltage to stay above 12V. Let's assume you charged them to 14.5 volts from the car's system.

cap current = C*dv/dt (D = change in)

rearanging, dv = (dt*i)/c. For the 2 stages, you have to seperate two occurances:

Dv = (dt1*i1)/c+(dt2*i2)/c Where dt1 = .5sec, i1 = 500A, Dt2 = 2sec, i2 = 150

For DV = 2.5V For (14.5V-12V),

so 2.5V = 250/c+300/c, 2.5 = 550/c

c= 220F

500A and 150A may be pretty marginal. I'm not sure what the starter actually draws...

How much is 220F worth for the devices you are talking about?

A couple more things to think about...why not diode isolate the cap unit from the battery, and run the stereo off the caps, rather than try to start with them.

If you run 15A on the stereo, and you had a 200F bank, and you could accept running between 14.5V and 12V it would last:1200 MINUTES.

The only trick would be to control the charge current when you charge them back up. It will max your alt out until they are charged, because they look like a dead short to voltages above what they are charged at.

For example, if the 200F cap was at 12V, the alt would have to pump it max current (Let's say it has 30A extra to charge the caps) for 600 minutes. You could limit this (Which is what i would definately do) with a power resistor. For example, to limit the current charge to 20A, and a max diferential voltage of 4V (Let's say you ran them down to 10.5V) the resistor would be 1/4 ohm. The power is high though, 100W.

The diode would have to deal with this charging current as well, but that can be had no problem.

Chay

Loked up the batcap...I don't know how informed the posters are, but it seems to be just a thin film low impedance battery. If so, my guess is it will wear out fast.

Chay

Check this out:

http://www.maxwell.com/ultracapacitors/products/medium-cell/bcap0350.asp - http://www.maxwell.com/ultracapacitors/products/medium-cell/ bcap0350.asp

Chay

http://www.tecategroup.com/store/index.php?main_page=product_info&cPath=18_20_32&products_id=1220 - http://www.tecategroup.com/store/index.php?main_page=product _info&cPath=18_20_32&products_id=1220

Wow. These came way down in price! These caps are 310F (Huge) and only 2.5V. Series them up and you loose capacitance....

So, 6 caps in series (To acheive the require voltage rating of 15V) yeilds a measly 55F. Then parallel some chains to up the capacitence again, 4 chains will give you 220F. Total cost = $16*6*4 = $384...not too bad.

Chay

http://www.tecategroup.com/store/index.php?main_page=product_info&cPath=26_62_66&products_id=112 - http://www.tecategroup.com/store/index.php?main_page=product _info&cPath=26_62_66&products_id=112

Looks like they thought about automotive too. Cost = unknown. 100F box, the size of a big shoebox.

Chay