Ok, I currently have a abunch of electrical items and am still running the stock battery and alternator! Below is a list of my electronics I am running! Well the problem is whenever I turn my system up and have my lights on, all my gauges dim to the point they are almost off! Now I want to retain the fact that I can take out by box and heavy items easily for track days, but for DD I want to fix the Gauges from dimming! Please what do you think would be the best solution! I dont want to pay a fortune for this! Also if I add a second battery...what size power wire should I run to it, and what is the best way to hook it up?

Bigger Capacitor or another one? Add second battery in trunk for system? Bigger alternator? Thank You for your help!

Electronics
AEM UEGO Wideband 02 Sensor
Prosport Boost Gauge
Prosport Exhaust Temperature
Prosport Oil Pressure Gauge
Prosport Oil Temperature Gauge
Prosport Fuel Pressure Gauge
Cobra Radar/laser detector
TOMTOM One GPS
Python 990 Alarm
Rockford Fosgate T1 12” Sub
Directed 1200 Amp
2 Farad Capacitor
Pioneer AVH 9700 DVD Player

 

Are you taking all power for your system directly from the battery via a separate wire, or are you tapping off other wires? Simple question, but this is the most likely problem without finding out more.

Also, do they still dim with the engine running?

 

yes, its dimming while driving down the road! Sears checked my battery and load and said that the battery and alternator is working perfectly! Just that my system hass too much pull for the battery! The gauges arent installed yet, will be by the end of the week! Radar is a single wire to the battery, tomtom is in the cigarette lighter, Alarm installed by ABC Warehouse and spliced into god knows what harness wire! The installer is damn good tho and knows his ****! DVD is in the stock harness, and the AMP/Subs are powered by a 4 Ga power cable to the battery with a 2 farad capacitor!

I think that I need to add a 2nd battery in the trunk for just the system, removabke for track days, or A BIGGER Capacitor, or just another capacitor with the one I have now!

But Im trying to figure out what the safest and best way of doing this! My amp/sub are running at about 1500 watts!

 

If the gauges are dim all the time when you drive, increasing the size of the capacitor will not help. The capacitor will discharge completely in a very brief moment and will compensate for brief, huge current requirements from your subs. I'm sure you know this already.

I'm still worried that your gauges are going dim when driving. At 1500 watts and a conservative guess of 50% efficiency, you could be drawing 250 amps, and I think a car battery with working alternator should be able to supply that, even though it's a lot.

I would suggest getting a multimeter and checking your battery voltage off the terminals and from the back of one of the dim gauges. The voltage should be the same and should be over 13V. If not, then you could have bad wiring, a bad battery, or a bad alternator. Do you have a small battery or the stock one?

You could also try jumpering a second (charged) battery to your stock one temporarily to see if that cures it. Make sure you get the polarity right!

 

They dont stay dim, they are at full brightness, but everytime the sub hits hard, the lights dim! Sears checked the battery with the sub load and the car running, and said they the battery and alternator were running perfectly! In my celica with this setup I had an Optima red with the 2 Farad Cap and it was fine, however the Optima I had wouldnt fit in my EVO so I still have the stock full battery! I dont really want to pay $200 for another Optima, if I could fix it with another $75-100 Capacitor or add a $50 battery for the sub!

 

Ok, I think im going to install a 6 farad capacitor along with my 2-farad! This should be plenty to take the brute of my sub hitting and the lights dimming with each punch! The guy I talked to at sears said he had to install 2 of the 2-farad caps that I am running and that took care of the dimming in his car!

 

an upgraded alternator is the ONLY FIX for this issue, anything else is just a short term bandaid.

 

OK, if the lights dim when the sub hits hard, then an upgraded capacitor will help to some extent. Connect the capacitor as close to the amp as possible, i.e. away from the battery. Also look for a replacement battery that has a high peak current handling capacity.

An uprated alternator will help keep the battery charged, but even a small battery can supply much more peak current than any alternator.

Note: adding a bigger alternator will increase the total amount of current that can be supplied - it may be enough to fix your problem. I'd use this as a last resort though since changing an alternator is not as simple as changing a battery or adding a capacitor.

 

If I went with an alternator, where would I get it, and how much?

 

I dont agree with this.

The ONLY part of your electrical system that generates power, is the alternator, while a QUICKLY charging battery will help slightly, its still a battery that needs to be charged. All a battery is, is a storage of alternator output.

 

I agree, a capacitor is useless and a waste of money. An upgraded alternator is a much more worthwhile investment. I owned an excessive amperage 300a HO alternator. They make a great product. There is also mean green and a few others. A second (or main) battery from Kinetik would help as well.

 

An average battery can supply more current than even a powerful alternator, hence lights dimming are likely down to a problem with a small battery or a system that is drawing current for brief periods that exceeds the maximum current capability of the car's power system. A capacitor can supply tens of thousands of amps for brief periods, a battery can supply thousands, but an alternator can only supply current in the low hundreds.

If the battery is repeatedly going flat, then it is obvious you need a new alternator. If not, then the alternator is actually able to charge the battery despite the current draw of the system. Of course, adding a more powerful alternator will increase the total amount of current your car's power system can supply, but I am saying you do not need to consider that your only option. It will probably be easier to see the effect of replacing your battery and/or adding a capacitor.

Remember that lights dimming when the sub hits are because the current draw exceeded that of the capacity of the power system for a brief moment. A battery repeatedly going flat means that the average current draw exceeds the amount that the alternator can supply. His problem is the former, not the latter.

 

Thanks alot for your help, I just ordered a 6 Farad Cap that I am going to add to my 2 Farad I currently have! They will both be mounted on the box with my amp with less than 2 feet of wire between both of them to the amp! I really dont want to change an alternator, it doesnt look too fun on an EVO where its located! And I dont really want to buy a great battery for the fact of hopefully this winter I will be adding an exhaust and intercooler and have to use a mini battery for that anyway!

 

a capacitor won't help. a battery won't help. the ONLY solution is an upgraded alternator. For your Amplifier ALONE, at 50% load, you are pulling 41-50 amps. at 100% load, you are pulling 82-100 amps.

your alternator has a max of 90amps.

so, start adding all your amp draw out... and you will see that you are consuming more power than your alternator is creating.

Your battery and capacitor will take care of a TEMPORARY over-draw, but continuous excess draw will cause your battery to drain, and the resulting voltage dips.

Upgrade your alternator. simple

 

where can you buy and upgraded alternator for an evo?