battery handling???

[henrytad]

hey everyone, im currently running a sony head deck with a KICKER zx700.5 5 channel amplifier running a 8 FARAD soundstream capacitor, 2 rockford fosgate p2 subs, kicker front components and rear 6 by 9's. when i turn my decks volume up to about 30 i get amp cut outs, lights dimming and i have a battery gauge and it drops from 12.5 Volts (idle) to 10.5-11. is this normal? or does something need to be done?

[Timmos]

My first thoughts are your alternator is dying...

[henrytad]

how do i check my alternators situation?

[sweefu]

What guage wiring are you running? What Gauge & Where are your earths?

[henrytad]

im running 4GA Wire around the sound system alltogether. i have one of those calibre battery volt gauges you get from supercheap auto which shows my voltage. in early morning when i turn my car on, the car revs hard for about 2 minutes then idles normally, what does that mean? and if i drive straight away when i turn the car on the car drives really slow. ive always thought maybe alternator may be a problem, or battery? or i dunno

[SuperSixty6]

What size battery are you running? 550CCA at least?

It is definitely normal for you too experience voltage drop when your sound system is running hard. But your system should at least be reading 13.5v as your alt chargers at 13.8v

[holdenboy]

Firstly, check your alternator by starting the car and leaving it idling, turn off the stereo.
Get a multimeter and set it to volts DC, if its not autoranging then set it to "20v".

Put the probes on the correct battery terminals and note the voltage, as said above it should sit around 13.8-14.2v.

Now turn your high beam headlights on and re-check the voltage. It should read 13.4-14.0v, if its anything less than 13.4v then your alternator is not providing enough amps and needs to be repaired.

[henrytad]

ill have a check of it tommorow, after all its long weekend ahhahaha... but also is there any possibility the batteries on its way out ? its about over a year old though, but it has been thrashed coz of the sound system neons n everything.

[holdenboy]

Yep thats a possibility.....can also take it in to your local battery place and they can load test it.

[SuperSixty6]

ill have a check of it tommorow, after all its long weekend ahhahaha... but also is there any possibility the batteries on its way out ? its about over a year old though, but it has been thrashed coz of the sound system neons n everything.

Haha! Mate neons don't put much stress on your battery

I originally thought battery Failure, However on charge (When car is running) your gauge should be reading 13.8v regardless of whether the battery has failed or not.

[Denno]

I don't think you have said explicitly, so I'll ask. Have you upgraded the connection between your battery negative and your chassis? When I did this with my car, it helped massively with the light dimming. Didn't stop it altogether, but it definitely made a difference. Just throw some more 4gauge from the battery negative to a good connection on your chassis, preferably as close to the terminal as possible (so keeping the cable as short as possible).

Denno

[henrytad]

ok ill try connecting a new wire from the negative to a chassis. i used my multimeter on the weekend to get some results. with the car off, my batteries on about 12.5 volts, headlights on drop to about 11.8V and with the car running lights on etc, 14.2V. when i fire the sound system up to full blast i get massive drops

[holdenboy]

Disconnect the capacitor and see if it gets better or worse.

The charging / electrical system seem fine by those figures, so it has to be something in the system. If you were running several thousand watts then it could be explained, but your system shouldnt draw the voltage down below 12.5v at any time while the car is running.