Hi, After installing my sound system im getting great power drain, my lights are dimming when the deep bass notes hit, while the engine is running and the system is off my cars voltage is only 13.8 - 14.0 with my system on its 12.6 - 13.0 and with it pumping its 10.8 - 12.0 I had a 4 Farad capactior as well, i thought that might help things, it has made the subs more responsive but no help on power drain. im thinking of getting a new alternator, whats the way to go? can i get really good ones that are more efficent? or is there only 1 to get for a VS Calais 5.0litre? ANy help on this subject would be awesome... Cheers.
Some people go for a second battery in the boot whilst others go for the largest battery and heavy cables plus an upgraded alternator. Not sure what your alt puts out but remember that the rated output is at mid to high revs - at idle you may not notice any difference. Big heavy cables make a lot of difference and are not expensive. Those voltages you quote - are they from the battery + and - terminals or a feed wire (reason being that low volts may be due to wire resistance)?
Police alternator. I think the standard alternator is 90amp, but that there was a police pack alternator of 120 amps. Not sure of my facts, but you might be able to source a higher output alternator.
the voltage was taken from a stinger positive battery terminal with voltage display. these were also checked on the 4 Farad capacitor in the boot. Im running 4Gauge cable for my sound system.
I would go with a higher output alternator and consider a second battery. Your battery won't last long like this, It won't be getting charged enough. The standard alternators aren't designed for that kind of draw. Standard alternators ouput 90-100 amps. With the ignition system, lights, air-con fan, cooling fan and any other accessories running you can get close to drawing most of that. Add a huge amp and you will be over which will stress the alternator and belts (more current being drawn, harder it is to spin) and start to drain your battery rather than charge it. I'd go a high output alternator and as heavy a duty battery you can get for the car. If that doesn't help enough, go the second battery to reduce the drain. The second battery will still require a higher output alternator unless you plan on charging it separately.
i was thinking maybe a second battery, how would i weird it up so i dont have 24volts, i did you basic electronics a few years ago, and i know its either series or parallal but i cant remember which one and how to connect it. I can pickup a new bosch alternator for my car for $120. but im unsure of the AMPs it puts out. any ideas on a alternator that puts out big amps.
It may be worth researching caravan and camping forums. Its common to have a 12 volt system to run your camping gear using a deep cycle battery. When you drive off to your next destination the battery charges off the car. I'm pretty sure they use some circuitry to ensure it doesn't drain too much from the vehicle all at once, especially if the battery is pretty flat, to protect the alternator. I'm sure some specialist car audio forums will also have some suggestions.
4WD owners will also generally fit a second battery - they use an isolater device which makes sure the main battery is fully charged before diverting power to the second one. They also stop one battery draining into the other. They cost under $100.
The Optima Yellow Top battery is designed for car stereo applications - it can supply power faster than a normal lead acid battery. It can be charged a lot faster and has a reserve capacity. I bought mine from Battery World for around $300 and love it. Engine cranks over heaps better and stereo is heaps better. See an autoelectrician for advice. watch your stereo gear with low voltage... with low voltage/high current draw, the amps can burn out. Seen $3000 amps meltdown because of this.
