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-   -   is anyone running a capacitor? (http://www.wakeworld.com/forum/showthread.php?t=797618)

bass10after 04-10-2013 8:39 PM

is anyone running a capacitor?
A buddy asked me about this today and actually hadn't really heard of anyone using one in a while... Seems like it used to be popular or something everyone did but not so much anymore. Do any of you guys/gals run one?

wakerider111 04-10-2013 8:47 PM

wake boats cant get up to 88 mph so no one really bothers :P

Houstonshark 04-10-2013 9:07 PM


chpthril 04-10-2013 9:30 PM

We are using Mr Fusions exclusively


Seriously though. No, been doing this for a number of years and have never installed a CAP in a boat. In the words of Billy Joel, "You get more miles from a cheap pair of sneakers" or in other words, you get more play time from a larger battery bank. Dimming head lights when the sub hits is not a problem on boats.

david_e_m 04-11-2013 7:48 AM

A stiffening capacitor is fine for a daily driver but not a good idea for any craft/vehicle that is in storage long term. It can actually become a liability in a boat. Plus, it would do nothing for the real supply problems related to a boat versus a car.

Earmark Marine

bass10after 04-11-2013 8:56 AM

guess i should have clarified a little better, although being a boat forum my q should have been directed at just boats. I was wondering about cap's in general-cars/boats/utv etc.. I feel like i used to hear about them a lot more 5 years ago, but not so much anymore. I was wondering if battery technology caught up to allow more amperage draw quicker, maybe they were just a phase, or maybe i'm just out of the loop and people are still using them....

philwsailz 04-11-2013 9:22 AM

To put it in layman's terms, caps can be considered a bandaid for less than optimal power wiring.

If you had too small of a power wire setup, or a poor ground where the supply wiring was current limited, the capacitor would step in and provide the instantaneous current/voltage to prevent the voltage sag that would go with a big bass note hit.

If your wiring was correctly sized to the amplifier, with a good solid ground connection, and if you had a good battery with solid clean connections there, the capacitor is to a large degree unnecessary. A properly designed power wiring system basically prevents the need for a capacitor as the properly designed power system provides the current and voltage that a big bass note needs. That is the very short and sweet of it.

There are going to be exceptions to this set of parameters I have pointed out; there always are.... For example, for some car installations where the power wiring is totally proper, some folks will experience that headlight dimming, but others will not. Those point ot differences in alternators, charging systems, relative system needs, amplifier power, etc...

As always, my explanations tend towards somewhat of a simplfication in order for the largest audience to grasp the concepts presented. It is rarely a totally-enveloping answer that addresses all tweaky little minute exceptions... :D But to the bottom line, for a properly designed and installed system, most people will find capacitors are not necessary for proper electrical function. It is often just a nice touch of bling some folks decide they want to add...

David, care to elaborate?


brianinpdx 04-11-2013 10:57 AM

The issue is the long term storage guy. Over time that capacitor 1F, 5F 20F (whatever) starts to rob current from the supply to keep itself fully charged. This isn't a good situation. This doesn't typically happen in the auto world due to the nature of consistent use of the vehicle.

The use of caps gained popularity in the hey day of IASCA sound off competitions. The idea was that when running 0 gauge from the front to the rear of the car the system would experience a fractional voltage drop. By putting a cap within close physical proximity of the amplifier, the system would regain this lost voltage. And a by product of the capacitor is it would "stiffen" the transient response of the amp. All this stuff is well and dandy but has very little practical application in the everyday world.

In my past life, at PG, one of my last products I did was the Powercore 15/30. It took this idea to the limit. I designed it to look like an actual amplifier. We sold 100's of these things to competition guys. This product is long since extinct.

[IMG]<a href="http://s1112.photobucket.com/user/brianinpdx/media/6235300071_large_zps294fb177.jpg.html" target="_blank"><img src="http://i1112.photobucket.com/albums/k491/brianinpdx/6235300071_large_zps294fb177.jpg" border="0" alt=" photo 6235300071_large_zps294fb177.jpg"/></a>[/IMG]


david_e_m 04-11-2013 12:43 PM

Sure. I can add a little detail to that. Thanks.
If you have a voltage drop from the front to rear of the vehicle because of insufficient cables, a stiffening capacitor cannot remedy that. A cap cannot raise the voltage beyond the supply in any way or form. It can only stiffen or maintain the voltage for a small fraction of a second based on the voltage across the capacitor terminals, and not the voltage at the battery or alternator terminals. There is no impetus for current to flow to the capacitor unless the supply voltage is greater than the capcitor voltage. Plus, it takes a mighty big capacitor to see a benefit....because if you exhaust the capacitor charge below a percentage of its storage capacity it no longer can stiffen the voltage. Remember that a capacitor must recharge in between transient demands. Yes, a capacitor can release its voltage at a faster rate than a battery and it is elastic in its ability to provide a voltage buffer that momentarily props up the voltage but if the cycle is too long or the cycle is too large, a depleted capacitor is more of a liability than an asset.
The problem with a capacitor in a boat is not the parasitic draw because you would normally be shutting it off with a battery switch when the boat is placed in storage. The problem is that once you introduce the capacitor to the battery AFTER storage, you are rapidly and violently recharging the capacitor. With repetition that will damage the capacitor and in a damaged state the cap is actually hurting the charging system. You could slow charge the cap every time with a resistor, just like you would during the initial installation, but that is really inconvenient and most wouldn't do it.
As an esoteric additional to a vehicle once every other charging system refinement is managed, I can see it.
In a boat it's just plain impractical. In a boat you should focus on improving the batteries and having the right AC shore charger. Again, a capacitor can stiffen the supply but never raise the supply.

Earmark Marine

philwsailz 04-11-2013 6:53 PM


Originally Posted by brianinpdx (Post 1816284)
The idea was that when running 0 gauge from the front to the rear of the car the system would experience a fractional voltage drop. By putting a cap within close physical proximity of the amplifier, the system would regain this lost voltage.

Huh?????? We create a voltage potential in any device by exposing it a voltage greater or equal the desired voltage. Are you suggesting you could put 11.7 volts in, ( a byproduct of voltage loss in the wire) and get 12 volts out? I find this fascinating for a passive device!

How did you get the cap up above the supply voltage it was connected to? The only time I have seen similar straight-wire gains came from proper cryogenic freezing, followed by green ink, polarized speaker cables and a properly burned-in Tice clock...


hatepain 04-11-2013 9:08 PM

Yes, we call them big batteries and thick cable.

brianinpdx 04-11-2013 10:21 PM

Sorry Phil - "current" not "voltage". Been a long day. And yes, close proximity. usually Auto distro blocks feature 2 pwr inputs (1 for the supply i.e front of car and the second for a cap). And 1 ground - Chassis. The point being, keep it close to the amplifiers themselves. Some great tech speak if you all want more on this subject:

http://www.alumapro.com/docs/capcomps1001.pdf (Pg1)

http://www.alumapro.com/docs/capcomps1002.pdf (Pg2)

http://www.alumapro.com/docs/capcomps1003.pdf (Pg3)

http://www.alumapro.com/docs/capcomps1004.pdf (Pg4)

We used to build this product for them too. I think Ken @ alumapro still sells them for all the car enthusiasts.

Fixable 04-12-2013 7:09 AM


Originally Posted by brianinpdx (Post 1816397)
Sorry Phil - "current" not "voltage". Been a long day.

Pretty sure you meant Voltage.... Just not in the way you explained it exactly. You will not have a loss of current, in the wire, due to wire size.... If the wire is smaller than optimal for the application, you will have a voltage drop . The drop in voltage, will give you a drop in current. The current will not drop for any other reason.

Most of that problem can be cured with an appropriate sized wire. Overkilling it will not hurt. The larger the wire, the less voltage drop you will have. Even if it is 4x larger than optimal.

Caps will not increase available voltage or current availability. They simply smooth out the transition from the supply source to the demand draw.

DealsGapCobra 04-14-2013 3:52 AM

Funny, after reading this thread, I came across this add...


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