Capacitor/amp how to questions

[lipski24.ml 10+ year member]

Alright my first question about capacitors!

1) What is a farad?

2) Do you want more farads?

3) what is the cheapest but yet reliable capacitor to buy??

4) I don't have any wires to the capacitor, and do I just use the amplifier install kit wires?

I have a scosche 500k micro farad capacitor without the wires. Is it a decent capacitor? Can I use the amp kit wires for it?

5) How do I wire the dang thing correctly?

I'm a capacitor and wiring noob so lots of help needed!

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[SounDrive Pro Seller]

Answer to all 5: capacitors are completely useless in your situation - avoid them.

 

[lipski24.ml 10+ year member]

I am going to be running a Kenwood kfc3013ps off a Audiopipe Apsm1300. So I kind of figured it would help. But do you think I should do the big three just for good measure? Or is that a bad thing?

 

[SounDrive Pro Seller]

I am going to be running a Kenwood kfc3013ps off a Audiopipe Apsm1300. So I kind of figured it would help. But do you think I should do the big three just for good measure? Or is that a bad thing?

Doing the big three should be enough for that amp, depending on the size of your stock alternator. Maybe consider getting an AGM battery for under the hood if you think you need a little bit better electrical to back it.

And standard capacitors don't have enough capacitance (storage) to be able to supply your amplifier for more than a few milliseconds, at which point its charge is gone and it just puts more of a load on your vehicle's electrical system.

 

[lipski24.ml 10+ year member]

I have no idea the Alternator size. It's a 99 Chevy Blazer ls. So if that helps any! I will do the big three then! AGM battery? Sorry, i am new to all this. I'm constantly learning new stuff on here though! Ha!

 

[keep_hope_alive Premium Member]

Alright my first question about capacitors!1) What is a farad?

2) Do you want more farads?

3) what is the cheapest but yet reliable capacitor to buy??

4) I don't have any wires to the capacitor, and do I just use the amplifier install kit wires?

I have a scosche 500k micro farad capacitor without the wires. Is it a decent capacitor? Can I use the amp kit wires for it?

5) How do I wire the dang thing correctly?

I'm a capacitor and wiring noob so lots of help needed!

1) Farad is a measure of capacitance. higher value means more energy storage. Wiki "capacitor" and read. note that caps have a voltage rating. this is the voltage that shall not be exceeded, a rating of what it can handle, not what it will provide. caps will mirror the voltage of the source and also resist drops in voltage as long as they can meet the need, but they will drop in voltage as they supply current, then they need to be recharged and then act as a load. the amp uses caps for that purpose, to stabilize the DC rectifier. but the overall process is inefficient and the internal caps won't help the vehicle's electrical system.

2) yes. more is better. Wiki will also explain what happens to capacitance and voltage when caps are wired in parallel or series.

3) cheap means it doesn't do squat. cheap is 1 Farad. cheaper is 0.5 Farad (= 500k micro F).

4) 500k micro Farad is nearly useless. it can be used to hold papers in place. it can be used to make small sparks for fun.

5) a cap needs to be wired to the electrical system. you typically run power wire to the cap (+) and secure with a ring terminal. then continue to the amp (requires another ring terminal). same with ground (four ring terminals total). so positive wire from battery (through fuse) to cap positive to amp positive. ground wire from chassis to cap negative to amp negative. viola!

you deserve honest answers to your questions.

you have received the correct advice to just focus on the Big 3. I agree.

you don't need to use the 0.5F cap you have. it will just be a hassle. I did install a 0.5F once, and my build log shows that effort. it was removed because despite being installed as well as possible (literally the wire to the amp was 1" long), it still did nothing appreciable.

Tenac mentioned "standard capacitor". I know what he means by that, but I think it important to be understood. standard caps use a metal foil to create surface area. capacitance is a function (in part) of the surface area of the plates and the distance between them. more area and/or less distance = more capacitance. cylindrical caps have the plates wrapped in a spiral. another type has been available for a while and they are called super capacitors or ultra capacitors. they use carbon sheets which have 3,000-6,000 more surface area due to their fibrous nature. as a result, their capacitance for the same size is much, much higher.

I run six 2.7V 3,000F (Maxwell BCAP3000) caps in series for 16V and 500F (= 500,000 micro Farads). It does stabilize voltage and could start my car without a battery. my cap bank costs around $400 new ($65 each on Mouser + bus bars and ring terminals and wire and fuse holder for disconnecting).

an ultra capacitor bank costs the same as a H.O. alternator but the alt is safer and overall a better option. high energy storage cap banks are dangerous and I don't recommend them to a novice. you need to have a good understanding or have someone like me on speed dial and in person to oversee the install and discuss the risks of storing something with that much energy that can be released quickly. note I have a H.O. alt and big 3 and an excellent battery as well, and did those long before adding an ultra capacitor bank. if I had spent the money on a larger H.O. alt, the ultra capacitor bank would not be necessary. for those reasons, I recommend H.O. alts over any type of capacitor.

cheers

 

[keep_hope_alive Premium Member]

AGM is Absorbed Glass Matt. it is a type of sealed lead acid battery (also called Valve Regulated Lead Acid or VRLA). this battery type is more robust, and doesn't require you add water. it also performs better.

I run a Sears Die Hard Platinum Group 34/78 (dual side and top posts for easy aftermarket wiring while using factory battery terminals). This comes with a 4 year replacement and then another 4 year pro-rated warranty, better than anyone else. they sell for $200 at Sears. there are others like it with shorter warranties. look for Reserve Capacity (RC) when comparing batteries.

replacing an alt may be easy, may be a PITA. depends on the vehicle. Quality Power in CA is one source. Ohio Generator is another. Budget $300-$400 for a good one). it requires upgrading wiring associated with the charging and grounding system (Big 3). this is tedious as it means you are adding thick wires to an engine bay. make a mistake or have your wiring fail and you are stranded. it's not hard, but attention to detail and good wire termination methods matter. I detail my process in my build log also.

 

[keep_hope_alive Premium Member]

BCAE1 Capacitors Explained

this also answers your questions

 

[lipski24.ml 10+ year member]

Thank you! I will stay away from the cap! And while doing the big 3 i will have my step dad help me, who is very intelligent when it comes to almost anything! Ha! But thanks again for all the help! Sounds like you know your stuff man, impressive! I may upgrade the battery as well and may need a future reference! But i will probably ask my uncle who is mechanic to help me out! Thanks again!

 

[keep_hope_alive Premium Member]

Thank you! I will stay away from the cap! And while doing the big 3 i will have my step dad help me, who is very intelligent when it comes to almost anything! Ha! But thanks again for all the help! Sounds like you know your stuff man, impressive! I may upgrade the battery as well and may need a future reference! But i will probably ask my uncle who is mechanic to help me out! Thanks again!

happy to help. when explaining the big 3 to a mechanic, explain that you are simply reducing resistance associated with charging cables between the alternator and battery. two ground wires and one power wire.