I got a 1.5 fahrad cap on my system that I am trying to charge. I am using a 12v car battery charger to do it. I put the negative clamp from the charger onto the chassis and the posotive clamp on the + on the cap with a 12v bulb inline. It seems to charge fine to 14.4 volts, but then when I remove the charger the cap starts droppping majorly in voltage. After a minute or two I check the cap with a multimeter and it is only pulling 5 volts. The cap has the ground to the chassis. What gives?

 

uh, i'll take a punch in the dark here..

are you running the "power" from your battery through the cap?..then to the amp..

please revise your post.

 

yes but you do not charge the cap with the posotive from the battery attached to the cao, right? heres what I have

1.) cap grounded to chassis
2.) power from battery NOT hooked up to th cap yet, I was nder the impression you hook that up AFTER you charge the cap.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hoodwinked &raquo;</TD></TR><TR><TD CLASS="quote">yes but you do not charge the cap with the posotive from the battery attached to the cao, right? heres what I have

1.) cap grounded to chassis
2.) power from battery NOT hooked up to th cap yet, I was nder the impression you hook that up AFTER you charge the cap.</TD></TR></TABLE>

Ok, first off, you're not really "charging" the cap, all you're doing is keeping the terminals scuff free by not creating the big spark that happens when you first hook power to a cap (same thing is accomplished by using a resistor).

2nd, if the amps are still wired to the cap, they will draw the power. Your best bet is to use the resistor trick if you're affraid of sparks and/or blowing the underhood fuse. You take the wire comming from the battery, and hold a resistor to it with say some needle nose pliers. Then touch the other end of the resistor to the + terminal of your cap. The resistor slows the power flow into the cap so there isn't a big spark, but your resistor will most likely burn up (no biggy). Now after it's been on for like 30 seconds or so, take the resistor away and stick the + battery lead onto the cap. You're done.

Another way is to disconnect the + wires to your amp(s) and tape them off. Attach your battery charger to the cap, turn the charger on (it will take like a split second if your charger is a normal one with like 10 amps @ 12 volts). Now hook your batter wire up to the cap, there shouldn't be any real spark since the voltage between your cap and your car will pretty much match. Now wire your amps back up, making sure to remember that line now has +12 so don't let the leads touch ground.

 

The easy safe way to charge a cap , hook everything up, without main fuse on amp power wire under hood, useing any 12v bulb, brakelight, signallight, domelight , place light in series in place of fuse ,[pos.pin on bottom of bulb to batt. or amp side and neg., side of bulb ,to the other end] the bulb will light up and slowly dim out, when out,cap is charged, also a good way to check cap, if bulb does not go out, cap is leaking, how bad ,dependes on how bright the bulb stays
hope this helps 94

 

Actually you are charging the cap. The resistor you use in series with the cap controls the current going into the cap. So it will cotroll how fast the capacitor charges. Once it reaches the battery voltage current will no longer flow through the resistor. So then you can disconnect it and connect it back up with no spark.

I don't use the resistor either

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">Actually you are charging the cap. The resistor you use in series with the cap controls the current going into the cap. So it will cotroll how fast the capacitor charges. Once it reaches the battery voltage current will no longer flow through the resistor. So then you can disconnect it and connect it back up with no spark.

I don't use the resistor either </TD></TR></TABLE>

A lightbulb is a resistor 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">Actually you are charging the cap. The resistor you use in series with the cap controls the current going into the cap. So it will cotroll how fast the capacitor charges. Once it reaches the battery voltage current will no longer flow through the resistor. So then you can disconnect it and connect it back up with no spark.

I don't use the resistor either </TD></TR></TABLE>


Yeah, but I hate using the term charging, since a cap doesn't require a charge like most people know... like that of "charging a battery". Maybe I'm too picky lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rjr162 &raquo;</TD></TR><TR><TD CLASS="quote">


Yeah, but I hate using the term charging, since a cap doesn't require a charge like most people know... like that of "charging a battery". Maybe I'm too picky lol</TD></TR></TABLE>

A cap is realy nothing more then a very fast currant releasing batt. that cann't hold a charge very long by itself. 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">

A cap is realy nothing more then a very fast currant releasing batt. that cann't hold a charge very long by itself. 94</TD></TR></TABLE>

A capacitor and battery are very different. A battery converts chemical energy to electrical energy using three major materials: the anode, the cathode, and the electrolyte.

A capacitor can only store electrons it cannot create them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">

A capacitor and battery are very different. A battery converts chemical energy to electrical energy using three major materials: the anode, the cathode, and the electrolyte.

A capacitor can only store electrons it cannot create them. </TD></TR></TABLE>

DAH, 94